General hygiene and medical ecology

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Ministry of Education & Science of The Russian Federation
Crimean Federal University
named after V.I.Vernadsky
Medical Academy named after S. I. Georgievsky
Department of General Hygiene and Ecology
General Hygiene and Medical Ecology
TEXTBOOK
for Students of Medical Faculties
Simferopol
2018

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Recensents:
Prorector Crimean Federal University named after V.I.Vernadsky, Head of
the Department of pathological physiology Medical Academy named after S. I.
Georgievsky, doctor medical sciences, professor A.V.Kubyshkin
Head of the Department of medical biology Medical Academy named after
S. I. Georgievsky, doctor medical sciences, professor S.A.Kutiya
Textbook is reccomended for issue by Scientific Counsil of Medical
Academy named after S. I. Georgievsky 28.12.2017, protocol N 12
Shibanov S.E. General Hygiene and Medical Ecology. TEXTBOOK for
Students of Medical Faculties. – Simferopol, 2018. - 247 p.
The manual has been elaborated by the Head of the department of general
hygiene with ecology of the Crimean state medical university professor
S.E.Shibanov according to the State Federal Educational Standart and program
on general hygiene and ecology for the students of medical faculties and
elucidates the basic questions of the discipline.
The manual is designed for the students of the 3rd course of medical
faculties and the 2nd course of stomatological faculty.
The authors: professor S.E. Shibanov.
CONTENT
Introduction. Goals and Objectives of Studying General Hygiene and Medical Ecology

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at medical faculties
Theme No 1. Subject and Tasks of Hygiene and Ecology
Theme No 2.Hygiene of the Environment. Hygienic Regulation of Adverse Factors in
Objects of the Environment. Influence of the Environment Quality on Health of Population
Municipal Hygienе
Theme No 3.Hygienic Requirements to Microclimate
Theme No 4.Weather and Health. Prevention of Heliometeotropic Reactions. Climate
and Problems of Acclimatization
Theme No 5.Chemical Composition of Atmospheric Air. Effect of its Components on the
Man. Protection of Atmosphere from Pollution
Theme No 6.Significance of Solar Radiation. Hygienic Requirements to Lighting
Theme No 7.Hygienic Requirements to Drinking Water Quality
Theme No 8.Hygiene of Water Supply. Methods of Improving Water Quality
Theme No 9-10.Hygienic Significance of Soil. Hygiene of Inhabited Locality.
Hygienic Requirements to Cleaning Inhabited Locality from Waste Products
Hospital Hygiene
Theme No 11-12. Hygienic Requirements Hospitals. Prevention in-hospital infections
Hygiene of Nutrition
Theme No 13.Principles of Sanitary Examination of Foodstuff. Sanitary Examination of
Milk
Theme No 14.Principles of Rational Nutrition. Prevention of Alimentary Diseases
Theme No 15.Value of Various Nutrients in Nutrition. Functions of Proteins, Fats and
Carbohydrates in the Body
Theme No 16.The Significance of Vitamins and Minerals in Nutrition
Theme No 17.Food Poisonings. Reasons, Symptomatology, Prevention
Theme No 18.Medical and Prophylactic Nutrition. Prophylactic Nutrition
Hygiene of Work
Theme No 19.Subject and Tasks of Hygiene of Work. Physiology of Work. The
Occupational Harmful Factors and Occupational Diseases. Prevention of Occupational
Pathology. The Occupational Dust Pathology and its Prevention
Theme No 20.Hygiene of Work at Effect of Physical Occupational Harmful Factors
(Noise, Vibration, Electro-Magnetic Fields)
Theme No 21.Radiation Hygiene and Ecology
Theme No 22.IndustrialToxicology.Toxicology of Agrochemicals and Hygiene of Their
Application
Hygiene of Children and Teenagers
Theme No 23.The Physical Development of Children and Teenagers as a Criterion of
Health
Theme No 24.Hygienic Requirements to Children's Preschool Institutions and Schools.
Hygienic Requirements to Training, Physical Training and Hardening of Children and
Teenagers. Hygiene of Children‘s Nutrition
Hygiene of Hot Climate
Theme No 25.Hygienic Characteristics of Hot Climate and Its Effect on a Human
Organism. Hygiene of Nutrition, Hygiene of Work, Personal Hygiene under Conditions of Hot
Climate

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Final Control on Hygiene and Ecology
1. Key questions
2. Samles of Tests
3. Situational tasks
LITERATURE
Attachment 1 Students’ Independent Work. Evaluation of adequacy of an indi-
vidual nutrition
Attachment 2 Symptoms of poisoning by Lead and Mercury
INTRODUCTION
Goals and Objectives of Studying General Hygiene and Medical Ecology at Medical
Faculties
The purpose of studying hygiene and ecology at medical faculties is the formation in a
future doctor of hygienic thinking, i.e. understanding the interrelation between health and
quality (degree of the pollution level) of the environment that is a necessary condition of
scientifically proved systems of health protection, healthy lifestyle, effective public and
individual prevention of various diseases.
While studying hygiene and medical ecology, the students should acquire the
knowledge of:
 methodology, basic laws of a hygienic science and common laws of relation of health
with factors and conditions of the environment.
 origin, characteristics and laws of influence of the basic natural and technogenic
factors of the environment and social conditions on the ecological situation and health
of the population.
 methodology of studying the influence of the environmental factors and conditions on
health of various groups of population; qualitative and quantitative parameters of
hygienic estimation of the environment condition and its influence on health of the
population.
 methodology and principles of hygienic regulation of harmful factors in the
environment, organization and contents of preventive and current sanitary
supervision over medical-preventive establishments, inhabited and other objects of
sanitary-municipal purpose, establishments of nutrition, children's and educational
establishments, enterprises of industrial and agricultural manufacture.
 bases of a healthy lifestyle, personal hygiene and balanced diet, to be able to prove
recommendations for prevention of various diseases.
In the future professional activity the hygienic knowledge and practical skills are
necessary for the doctor in the following situations:
 At differential diagnostics of diseases, administration of treatment, medical-preventive
conditions and medical-labour examination.
 In the work on professional orientation, professional training and employment of
persons with a different level of health.
 At estimation and maintenance of sanitary-hygienic and antiepidemic conditions of
medical-preventive establishments, institutions of preschool, school and professional

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training, establishments of public catering and others.
 For optimization of conditions of life, education, training, work, prevention of
intrahospital and other infections, substantiation of recommendations on personal
hygiene, balanced diet.
 At development and realization of complex programs of prevention of various
diseases.
 In the work on propaganda of medical knowledge and hygienic education of various
groups of population.
Theme No 1.
Subject and Tasks of Hygiene and Ecology
Hygiene as a Medical Science
In medicine it is possible to distinguish 2 areas: medical and preventive. They are
interrelated and supplement each other, but are separate scientific disciplines. The object of
studying clinical medicine is a sick person (patient); its aim is diagnosis and treatment of
diseases.
The preventive medicine or "hygiene" (from Greek — "bringing health") studies a
healthy person (individual health) or health of the population of a region or country (population
health) with the purpose of maintaining or improvement of health. Specialists in this area are
referred to as doctors-hygienists or sanitary inspectors (abroad — doctors of public health).
The task of studying hygiene in medical university is to inculcate hygienic thinking in a
future doctor, which means:
 to be able to connect the occurrence of disease in a separate person or certain
population of people with the influence of factors of the environmental, industrial or
household surroundings, with sanitary conditions of life
 to be able to develop the appropriate measures for prevention of negative influence
of adverse environment factors on human health.
The Concept of Hygiene
Hygiene is a medical science studying the influence of environmental factors on a
human organism and on public health in order to prove hygienic measures, sanitary rules and
measures for maintenance and improvement of a human health and prevention of diseases.
Factors Influencing the Health of Population
According to the data of the World Health Organization (WHO), the health of population
of any country of the world depends on the following factors:
 in 48-53% — on socio-economic conditions in the country or region and a lifestyle
of a person (physical training, smoking, etc.)
 in 18-20 % — on the genetic factor (spread of hereditary illnesses in population)
 in 17-20 % — on quality (degree of pollution) of the environment
 in 8-10 % — on level of development and quality of medical aid.
Thus, the improvement of quality of the environment can theoretically produce a positive
effect two times greater than that of the development of the clinical medicine. It shows the
significance of preventive medicine or hygiene for improvement of health of population.

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The Origin and Development of Hygiene
A centuries-old history of hygiene can be conditionally divided into 2 periods:
Empirical hygiene (experimental hygiene) is a gradual accumulation of hygienic
knowledge by people from the time of primitive society on the basis of own experience or
experience of the previous generations (the use and preservation of various food, water from
different water sources, arrangement of habitation in different districts, etc.). The further
development of empirical hygiene took place in the slave-owning system, to a great extent
under the influence of religious instructions of Ancient East, Babylon, Greece, Rome. In the
Middle Ages the centers of medical science shifted from Europe, suppressed by inquisition, to
the East (the works by Avicenna or Ibn-Sina).
The period of empirical hygiene had been completed by the epoch of Renaissance in
Europe (15th century), by discovery of microscope and nature of infectious diseases (16-17th
centuries).
The period of scientific-experimental hygiene is a period of studying the harmful
factors influencing the health of a person in natural and experimental conditions (on laboratory
anivals) and development of scientifically grounded preventive recommendations.
The first known scientific work on hygiene was "Reflections on Illnesses of
Handicraftsmen" by Italian doctor B. Ramazzini in which the conditions of work of 52 trades
were described (17th century). In Russia the president of Petersburg medicosurgical academy
A. Frank (18th century) issued the multivolume book "A Complete System of Medical Police".
The first department of hygiene in the territory of the Russian empire was opened in
1863 at Kiev University, in 1865 — in St. Petersburg. The prominent hygienists in Russia
before the revolution were N. A. Dobroslavin and F. F. Erisman. In the Soviet period the
outstanding scientists-hygienists were academicians A. N. Sysin, A. N. Marzeev, L. I. Medved.
In USSR such eminent scientists as academician J. I. Kundiev (director of scientific
research institute of occupational hygiene), academician E. I. Goncharuk (rector of Kiev
medical university), academician A. M. Serdyuk (director of Ukrainian scientific hygienic
centre), A.N.Sysin (director of Moscow scientific research institute of general and municipal
hygiene was worked.
Subject of Hygiene
The subject of studying hygiene is health of a person and environment in their complex
interaction.
The environment in a wide sense is everything that surrounds person and influences
him.
In hygiene the environment is considered as 4 objects, which primarily influence the
organism of a person. They are:
 Atmospheric air and air of a working zone;
 Water of reservoirs and drinking water;
 Soil;
 Foodstuffs.
Table 1
Structure of Environment and Biosphere
Environment Biosphere
1. Atmosphere air (Air in premises) 1. A troposphere — a low surface layer of
atmosphere (10-18km)
2. Water of reservoirs and drinking water 2. Hydrosphere — up to 11km
3. Soil 3. A lithosphere — up to 12 km
4. Foodstuffs
Primary Tasks of Hygiene
They include:
 Studying natural and anthropogenic factors of the environment (table 2) influencing a
human being — their sources, reasons of occurrence, ways of influence on a person,

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basic quantitative and qualitative characteristics. In hygiene all the variety of the
environment factors influencing a person are subdivided into:
 Physical factors (noise, vibration, radiation);
 Chemical factors (various chemical substances);
 Biological factors (microbes, viruses, biological agents, etc.);
 Psychogenic factors (informational — a high level of negative information can cause
illness or even death of a person);
 Social factors (level of life, conditions of rest, etc.)
Table 2
Classification of Environmental Factors
Hygienic Ecological
1. Physical (noise, vibration, EMF, radiation, etc.) 1. Abiotic (nonliving nature)
2. Chemical (various materials, steams, gases) 2. Biotic (alive nature)
3. Biological (macro- and microorganisms, bioactive
materials)
3. Anthropogenic (man-caused)
4. Psychogenic (psychophysiological)
 Studying the influence of the environment factors on the organism (in natural or
laboratory experiments).
 Scientific substantiation and elaboration of hygienic standards, rules and
recommendations to decrease or eliminate the influence of harmful factors and
strengthen the effect of positive factors.
 Implementation of hygienic recommendations in practice, check of its efficiency and
further perfection.
 A scientifically grounded prognosis of sanitary situation in certain region or country for
the nearest and remote period on the basis of multifactorial mathematical modelling.
The Basic Sections of Hygiene
The contents of hygiene as a science is determined by the list of its basic sections:
 General hygiene (propaedeutics of hygiene)
 Hygiene of nutrition
 Municipal hygiene
 Hygiene of environment
 Occupational hygiene
 Hygiene of children and teenagers
 Hygiene of medical-prophylactic establishments
 Hygiene of extreme conditions
 Military hygiene
 Hygiene of hot climate
 Radiative hygiene
 Other sections — transport, sports hygiene, etc.
Methods of Hygienic Researches
Alongside with methods used in other medical sciences — physical, biochemical,
physiological, morphological, hygiene has a number of specific methods of research:
 Epidemiological method — studying health of population according to basic quantity
indicators as an integrated criterion of quality of the environment. The basic quantity
indicators of population health are:
 Demographic — death rate, birth rate, natality, average life expectancy, etc.;
 Parameters of morbidity (common sickness rate, morbidity, etc.);
 Physical development — (weight, height) — is especially important in children and
teenagers;
 Disablement (invalidity) of population (amount of invalids in population, reasons

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(diseases) of invalidity, etc).
 Method of sanitary inspection. The very first method in hygiene is a sanitary inspection
of an object (for example, a canteen with drawing up the act of sanitary inspection).
 Method of sanitary examination — examination of civil-engineering designs of objects
from the point of view of hygienic requirements, examination of foodstuffs (comparison of
product parameters to requirements of the state standards and making the decision on
possibility of food product realization).
 Method of hygienic experiment — studying the effect of a harmful factor on the
organism of animals in laboratory experiment with modelling conditions of real influence
on a person with revealing the affected organs and systems, the threshold and
noneffective levels of effect — is the basis of hygienic regulation of harmful factors.
The State Sanitary Inspection and Its Structure
Hygiene is a scientific part of preventive medicine.
Sanitary is a practical part of hygiene; its aim is application of hygienic requirements to
practice and the control of their fulfilment.
To fulfill this task, each country has a special public service supervising the observance
of the sanitary legislation. In Russia and Ukraine such special public service was called a
sanitary-epidemiological service (SES), which is a part of Ministry of Public Health of the
country.
From 2004 in Russia was formed Federal Service for Supervision of Consumer
Rights Protection and Human Welfare (Rospotrebnadzor RF), which includes Territorial
Administrations and Centers of Hygiene and Epideviology.
Types of State Sanitary Inspection
These are the following:
Preventive sanitary inspection — it is carried out at designing, construction and
putting enterprises in operation by means of sanitary examination of projects and sanitary
inspection of enterprise under construction in conformity with hygienic requirements. To this
also hygienic normalization of harmful factors in the environment refers.
Current sanitary inspection — supervision of observance of hygienic requirements on
functioning enterprise, control over the levels of pollution of the surrounding or industrial
environment, application of economic, administrative or criminal sanctions with respect to
those who infringes the sanitary legislation.
Bases of General Ecology
Ecology is a biological science concerned with interrelationships among living
organisms, encompassing the relations of organisms to each other, to the environment, and to
energy balance within a given ecosystem. Ecology(bionomics) issubdividedintothefollowingsections:
Autoecology — a section of bionomics which studies all ecological aspects of separate
species. Autoecology studies the effect of the environmental factors on each living organism.
Thus, an investigated organism is considered outside the link with other living entities of the
given ecological system.
Synecology studies communities of various living organisms, for example, the
community of microorganisms, plants, animals and their interaction with each other, as well as
with inorganic environment.
In ecology the hygienic concept "environment" approximates to the concept of
"biosphere", but ―biosphere‖ is a wider one.
The Concept of Biosphere and Its Structure
The term "biosphere" was introduced in 1875 by the Austrian scientist E. Zyuss. The
doctrine of biosphere as a complex multicomponent planetary system was created by V. I.
Vernadsky.
Biosphere — the sphere of life on Earth — includes:
 Troposphere — a surface layer of atmosphere (its height is up to 25 km)
 Ground — lithosphere (its depth is up to 10 km)
 Hydrosphere (depth of oceans is up to 12 km).

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Ecosystem is a set of organisms interacting with each other, as well as with the
environment, in which they live.
Any ecosystem consists of two parts:
The 1st part is called biocenosis. It includes all living organisms of ecosystem.
The 2nd part is called biotope. It is a part of the earth surface with particular
physicochemical properties, on which biocenosis lives.
Types of Ecosystems
 Microecosystems — a small stream, glade.
 Mesoecosystems — a sea, wood, pond, river.
 Macroecosystems — an ocean, continent.
 Global ecosystems — biosphere as a whole.
Larger ecosystems include smaller ecosystems.
Fig. 3. Types of ecosystems
Environment is a wider concept. The environment consists of biocenosis, biotope and
also physical, chemical, biological, anthropogenic factors (forces) effecting a living organism
(Fig. 4).
Fig. 4. Structure of the environment
Fig. 2. Structure of
ecosystem

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Ecological Factors
 аbiotic (factors of lifeless nature)
 biotic (mutual relations of alive organisms, trophic chains, etc.)
 anthropogenic (connected with a human activity)
At effect on a living organism the ecological factors depending on their intensity can be:
 irritants causing adaptive reactions;
 signals testifying to the change of other factors of the environment;
 modifiers causing morphological changes;
 terminators stopping or suppressing the vital activity of organism.
The rule of limiting ecological factors. The more the value of a separate ecological
factor keeps away from the zone of optimum for the given kind, the more it suppresses the vital
activity and is called limiting.
Ecological niche is a set of ecological factors providing the normal vital activity of the
given kind of organisms.
Ecosystem is a set of in common living species of living organisms and conditions of
their existence.
Biogeocenosis is a set of homogeneous ecological factors and species of living organ-
isms in a certain territory; it consists of 2 parts:
 ecotope — a set of аbiotic factors,
 biocenosis — a complex of living organisms.
The basic parameters of ecosystem are:
 Qualitative — a species variety of ecosystem, amount of species of living organisms
 Quantitative — a number of species of a separate kind.
Every ecosystem is in a condition of mobile-stable balance — homeostasis. A gradual
change of parameters of ecosystem under the influence of any factors is a succession of eco-
system.
The Laws of Existing Ecosystems
The law of ecological optimum (Fig. 5): The vital activity of organisms, their quality and
quantity conditions of life depend on different factors of the Environment. The zone of ecologi-
cal optimum is a range of values of ecological factor, optimal for vital activity of the given spe-
cies of living organisms. Above and below the value of ecological factor in the zone of optimum
there are zones (points) of pessimum (suppression of vital activity).
The range of zone optimum for each ecological factor for the given species of organisms
is called ecological valency of species.
Ecological spectrum of species is a set of ecological valencies on different ecological
factors. By width of ecological spectrum all species are divided into eurybiontic (for example,
eurythermal), having a wide spectrum, and stenobiontic, having a narrow ecological spectrum.
The zone of ecological optimum is a zone of comfort for living organisms, when the
environment factors act favourably on animals and plants. Quantity and quality of organisms in
this zone is greatest.
The zone of pessimum (depression) is behind (lower or higher) the zone of optimum.
The environment factors act unfavourably on animals and plants. The indexes of quantity and
quality of organisms are lower in this zone.
The critical point of life is the value of environment factor. In this point life is impossi-
ble.

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Fig. 5.
The law of trophic chain. The trophic chain is a chain of transmission of substance or
energy from low-organized to high–organized organisms in ecosystems (Fig. 6).
The first level of trophic chain is the level of producents (plants).
The second level is the level of consuments of the1st order (herbivorous animals).
The third level is the level of consuments of the 2nd order (carnivorous).
Fig. 6. A trophic chain
The law of accumulation of polluting substances in trophic chains. Polluting sub-
stances can accumulate in plants, herbivorous and carnivorous. Polluting substances are
transmitted from a lower to a high level of a trophic chain (Fig. 6).
The Significance of Studying Trophic Chains for Hygiene
In these chains due to bioconcentration toxicants may accumulate up to the levels dan-
gerous to a human being. Moreover, the loss of some parts of trophic chains under anthropo-
genic influence results in disappearance of trade species of animals or fish that can worsen the
quality of nutrition of population.
Interrelation and Differences of Hygiene and Ecology
Common features of these sciences are the following: they study factors of environ-
mental effect on organisms, maintain the environment (habitat) from degradation due to pollu-
tion. Changes in ecosystem sooner or later have a negative effect on conditions of life or
health of a person.
Differences are as follows:
 Different objects of research — a person (in hygiene) or living organisms (in ecology)
 Different methods of research in these sciences in connection with different objects of
research
 Differences in principles of normalization of harmful factors (in hygiene — maintaining

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health of each person, in ecology — preservation of basic parameters of ecosystem
with possible partial destruction of organisms).
Recommendations for Practical Classes on the Theme
Key Questions:
1. History of development of hygiene and ecology. Common features and differences of hy-
giene and ecology. Tasks of medical ecology.
2. Basic tasks and sections of hygiene. Basic laws of hygiene.
3. Basic methods of hygienic researches and examples of their realization.
4. Structure of the environment and biosphere, kinds of monitoring of their pollution.
5. Classification of factors of environment in hygiene and ecology.
6. The basic concepts of ecology: ecological factors, ecosystem, biocenosis, trophic chain.
7. Parameters of health of population and factors influencing the health of population.
8. Types of state sanitary supervision, the structure of sanitary-epidemiologic service of
Ukraine, the structure of sanitary-epidemiologic station (SES).
Self-control Test
1. Identify the major factors determining health of the population.
А. Climatic features, geographical position, degree of urbanization of territory
* В. Socio-economic, genetic, ecological, medical
С. Quality of nutrition, lifestyle, conditions of habitation, occupational factors
D. Lifestyle, national features, religious factors, social system
Е. Age, sexual, individual, hereditary factors.
2. Among the majority of factors determining health of the population, the following
group is greatest influence on parameters of population health:
А. Level of development of public health services and quality of medical aid to the popula-
tion
В. Level of a hereditary pathology
С. Educational and cultural level of the population
* D. Lifestyle and socioeconomic conditions
Е. Degree of the environment pollution
3. Identify the proportion of influence of the environment quality on the health of popu-
lation:
А. 45-53 %
* В. 17-20 %
С. 8-10 %
D. 24-25 %
Е. 15-17 %
4. What components are included into the concept "environment"?
А. Air, plants, animals, water, ground
В. Abiotic and biotic factors of the environment
* С. Water, air, ground, foodstuffs
D. Plants, buildings, ground, air
Е. Water of reservoirs, air, ground
5. What components does biosphere consist of?
А. Exosphere, ionosphere, mesosphere, troposphere
* В. Lithosphere, hydrosphere, troposphere
С. Air, water, ground, ecosystems
D. Autotrophic and heterotrophic organisms
Е. Space, globe

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6. What parameters of population health are the most sensitive to pollution of the envi-
ronment?
А. Demographic
* В. Sickness rate
С. Sickness rate with temporary loss of work capacity
D. Disability
* Е. Physical development
7. What diseases refer to ecologically caused (ecopathology)?
А. Diseases which worst yield to treatment in the given district
* В. Most frequently encountered diseases in the given district
С. Diseases, for which the role of the environmental factors is proved
D. Diseases among the most sensitive groups of population (children, elderly people)
Е. Diseases considerably differing in frequency in various regions
8. What parameters are studied at application of epidemiological method of research in
hygiene?
А. Parameters of pollution levels of the environmental objects
В. Frequency and incidence of infectious diseases among the population
* С. Parameters and indexes of population health
D. Incidence of endemic diseases in the given district
Е. Parameters of ecosystems condition on the investigated territory
9. What does the method of sanitary inspection consist in?
* А. The study of object with drawing up the act of hygienic inspection
В. Sanitary inspection of object with the purpose of its closing
С. Selection of tests of the environmental objects and their comparison with standards
D. The study of object quality as to conformity to the requirements
Е. Carrying out experimental researches on animals
10. What does the method of sanitary examination consist in?
А. The study of object with drawing up the act of hygienic inspection
В. Sanitary inspection of object with the purpose of its closing
С. Selection of tests of the environmental objects and their comparison with standards
* D. The study of object quality as to conformity to the requirements
Е. Carrying out experimental researches on animals
11. Identify the classification of the environment factors in hygiene.
А. Biotic, abiotic, anthropogenic
В. Air, water, ground, foodstuff
* С. Chemical, physical, biological, informative
D. Dangerous, harmful, indifferent
Е. Of natural and anthropogenic origin
12. Identify the classification of the environment factors in ecology.
* А. Biotic, abiotic, anthropogenic
В. Air, water, ground, foodstuff
С. Chemical, physical, biological, informative
D. Dangerous, harmful, indifferent
Е. Of natural and anthropogenic origin

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Theme No 2.
Hygiene of the Environment.
Hygiene of the environment is a section of hygiene studying medical aspects of the envi-
ronment protection as a scientific basis of prevention of unfavorable influences of the environ-
ment factors on a person at individual and population levels.
The following concepts of the environment exist:
 The internal environment of the organism is the internal content, the nervous and
humoral mechanisms of regulation and maintenance of homeostasis.
 The external environment is everything that is outside the organism and acts on its
membranes and receptors. From the point of view of physiology, the internal and ex-
ternal environments are very individual and dynamic for each person.
 The environment is everything that surrounds and affects the life and development
of an organism. It is not individual but common for the population. In hygiene the ba-
sic objects of the environment are atmospheric air, water of reservoirs, ground and
foodstuffs.
Depending on degree of influence of anthropogenic factors the following conditions of
the environment are distinguished:
 unchangeable (natural) — part of the environment not subjected to anthropogenic in-
fluence (reservations, etc.)
 changed (polluted) — as a result of human‘s activity, it can render negative influence
on people‘s health.
 artificial — the environment specially created by human (a spaceship, submarine,
etc.)
The Basic Sources of the Environmental Pollution
Natural and anthropogenic sources of the environmental pollution are distinguished.
Natural sources include volcanoes, earthquakes, floods, forest fires, typhoons, and oth-
er natural cataclysms. The dimensions of the environmental pollution in this case may be sig-
nificant, cover great territories, and levels of pollution may exceed anthropogenic pollution.
Anthropogenic sources are caused by human activity: industry, atomic power stations,
transport, agriculture, municipal services, etc.
Major factors of the environmental pollution are:
 chemical (pesticides, oil products, heavy metals, etc.)
 physical (noise, ionizing radiation, electromagnetic fields)
 biological (microorganisms, biological preparations, etc.)
Concept of the Environmental Pollutant
A pollutant is any natural or anthropogenic factor, being in the environment in amounts
exceeding the limits of natural fluctuations or natural background, or exceeding the permissible
standards for the given object of the environment. Not any presence of pollutant in the envi-
ronment is pollution.
Pollution is the presence of pollutant in the environment above the maximal permissible
concentration, which may produce an unfavorable effect on a human health.
Criteria of Danger of the Environment Pollution and Types of Its Monitoring
To estimate the danger of the environmental pollution is possible by the following criteria:
 According to the degree of excess of maximum permissible concentration of pollu-
tants in the environment — analytical monitoring;
 By integrated parameter — the health state of the population — medical-hygienic
monitoring;
 By changes in ecosystems — ecological monitoring (on a regional scale), bios-
pheric monitoring (on a global scale).

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The Basic Directions of the Environment Protection from Pollution
 Administrative-legislative measures of the environment protection on the interna-
tional, national or regional scale. These are priority measures, as they create a legal
basis for all nature-protective activity. Now there is a special direction in jurisprudence
— the nature protection law.
 Hygienic actions — realization of preventive and current sanitary inspection. The
preventive sanitary inspection is examination of projects of enterprises, capable to
pollute the environment, regulation of pollutants in objects of the environment. The
current sanitary inspection is the control of pollution levels of the environment, reveal-
ing sources of pollution and acceptance of measures to decrease pollution.
 Architecture-planning measures — a proper location of pollution sources for de-
crease of influence on especially important objects (for example, zones of sanitary
protection of water sources, functional zoning in cities, sanitary-protective zones near
enterprises, etc.).
 Medico-hygienic measures — studying the parameters of population health, reveal-
ing, treatment and health improvement of persons having disturbances of health due
to the environmental pollution. These measures allow revealing the most dangerous
sources and factors of the environmental pollution and the most sensitive to pollution
parameters of population health.
 Ecological monitoring — studying the condition of ecosystems and separate spe-
cies of living organisms under the influence of the environmental pollution with the
purpose of prevention of irreversible disorders of ecosystems.
 Technological measures: transfer of enterprises into the closed cycle (without emis-
sions into the environment), change of technology for decrease of emissions into the
environment (for example, transfer of motor transport into electricity), development of
sanitary engineering (cleaning constructions for purification of emissions into atmos-
phere, for reservoir burial, construction of areas and storages of waste products, etc.)
Hygienic Regulation of Harmful Factors in the Environment
Regulation of harmful factors in the objects of environment is an important element of
preventive sanitary inspection as it establishes the criteria of the permissible content of pollu-
tants in objects of the environment.
In hygiene there are 2 approaches to regulation of factors of the environment affecting
the man:
 In respect to natural factors (parameters of microclimate, lighting, ventilation of air, re-
quirements to nutrition), regulation is substantiation of optimal levels of factor values for
maintaining and improvement of human health or providing comfortable conditions for his
life and work.
 In respect to harmful factors in the environment there are 2 concepts:
 Concept of exception — absolute prevention of entering harmful factors in the envi-
ronment, but it is unreal because it means stopping industry, transport, power sta-
tions, etc.
 Concept of restriction — when it is impossible to eliminate the presence of a harm-
ful factor in the environment, it is necessary to confine its content up to safe for the
man levels — hygienic regulations.
The Concept of Hygienic Regulation of Harmful Factors in the Environment
It is such concentration, dose or level of the harmful factor in object of the envi-
ronment which neither cause any pathological changes in the organism of man and
subsequent generations (which can be found out on a modern level of development of
science) during the whole time of contact with this factor (during life or work expe-
rience), nor worsen the sanitary conditions of life of population.
Types of Hygienic Regulation of Harmful Factors in the Environment
Each country has its own regulations of harmful factors in the environment approved by
the state; there are also the international standards coordinated by the WHO and UNEP (the
program of the United Nations Organization for the environment protection).

16
In Russia such regulations are called maximal permissible (concentrations, doses, le-
vels):
 maximal permissible concentration (MPC) — for harmful substances in water, air,
ground, foodstuffs;
 maximal permissible dose (MPD) — for radiation;
 maximal permissible level (MPL) — for noise, vibration, electromagnetic fields;
 maximal permissible level (MPL) — for pesticides in foodstuffs;
 permissible residual quantities — for pesticides in ground and foodstuffs.
Apart from these regulations approved by Ministry of Public Health, the temporary regu-
lations for new substances are primarily elaborated:
 a tentative safe level of influence — for air,
 a tentative permissible concentration — in water.
Principles of Hygienic Normalization of Harmful Factors in the Environment
 Priority of medical indications at establishing a standard. At determining the value of
a standard only the levels of its safe effect on organism are taken into account, instead of
technical and economic reasons for observance of this specification.
 Differentiation of degree of biological response of organism to action of a harmful
factor. Depending on level of a harmful factor, which influences organism, and resistibili-
ty of organism to harmful influence we can distinguish the following levels of biological
responses:
 destruction of organism,
 llness,
 prepathology (disturbances of organism‘s functions without clinical signs of disease),
 tension of adaptive-compensatory processes (functional disturbances of unknown ae-
tiology),
 accumulation of substance in organs and tissues without functional and clinical
changes.
Regulations must be established not higher than the 4th level.
 Division of objects of the environment for sanitary protection. As each object of the
environment (air, water, ground, foodstuffs) has the physical and chemical features and
different conditions of contact with a human organism, regulations are established sepa-
rately for each object of the environment.
 Principle of registering all probable adverse effects of the normalized factor on a
certain object of the environment. There are the most important parameters reflecting
the harmful action of the investigated factors on quality of a certain object of the envi-
ronment. Such parameters are called signs or criteria of a harmful action. They include:
organoleptic, common sanitary, phytoaccumulative, water-migratory, air-migratory, reflec-
tory, toxicological, etc. (see table below).
Table5
Signs of Harmful Action at Regulation of Harmful Factors in Objects
of the Environment
Sign of harmful effect Type of unfavorable effect
Organoleptic change of odour, taste, colouring, etc.
Common sanitary influence on a saprophytic microflora, processes of
self-cleaning
Phytoaccumulative accumulation of pollutant in vegetative products
Water-migratory accumulation of pollutant in ground waters
Air-migratory evaporation of pollutant in the air not higher than MPC
Reflective irritating activity on mucous membranes of organism
Toxicological toxical effects on organism of animal
Specific allergenic, gonadotropic, embryotropic effects
The remote effects oncogenic, mutagenic effects

17
At studying each sign of harmful effect in laboratory a threshold concentration (TC) of
pollutant for each sign of harm is determined; the parameter of harmful effect with the least TC
is called a limiting sign of harmful action and according to it MPC is proved.
 Principle of presence of threshold (limiting) harmful effect is the central prin-
ciple of normalization. For each harmful factor there is a threshold of harmful action
— a level at which the harmful effect is registered (LOAEL) and a low level (NOAEL)
— when such effect is absent.
 Principle of dependence of harmful effect on concentration (dose) of the inves-
tigated factor and time of its effect. It is based on mathematical dependences
"concentration (dose) — effect" or "time — effect". The latter dependence is observed
at chronic effect in the presence of cumulation (chronoconcentration poisons).
 Principle of laboratory experiment. The investigations of effect of the normalized
factor on organism and sanitary living conditions are carried out in laboratory condi-
tions at unification and standardization of techniques for comparison of results re-
ceived by different researchers.
 Principle of aggravation. In laboratory researches the most adverse conditions are
modelled promoting the maximal manifestation of harmful effects of the investigated
factor. To the same principle the transfer of toxicological data received on laboratory
animals to the human organism refers.
 Principle of relativity of standards. The established standards are not constant and
final. At occurrence of new experimental data or results of negative effect of the nor-
malized factor on health of population at levels lower than maximal permissible con-
centration, standards are reconsidered towards decreasing.
The Scheme of Research of Toxicological Sign of Harmful Action at Hygienic Normaliza-
tion of Chemical Substances in the Environment
One of the most difficult and expensive for research signs of harmful action at normali-
zation is toxicological. It is investigated according to the following scheme:
1 Stage. Studying physicochemical properties of normalized substance with the purpose
of search of similar substances, for which standards are established, for an approximate eval-
uation of levels of toxicity and mechanisms of activity of a new toxicant.
2 Stage. Studying acute toxicity of substance (at one-time effect — lethal doses and
concentrations, threshold of acute harmful effect, etc.).
3 Stage. Studying subacute toxicity of substance at effect on experimental animals dur-
ing 30-45 days (ability to cumulation, etc.).
4 Stage. Studying chronic toxicity of substance (during some months or years — thre-
shold of chronic harmful effect).
5 Stage. Determination of threshold concentrations or doses by a toxicological sign of
harmful action. The threshold (LOAEL) and subthreshold concentrations (NOAEL) for the per-
son are determined on the basis of the data received on laboratory animals.

18
Features of Hygienic Normalization of Harmful Factors in Various Objects of the
Environment
Hygienic Normalization of Pollutants in Atmospheric Air
Pollution of atmospheric air among other objects of the environment represents the
greatest health hazard for the person for the following reasons:
 The majority of emissions of harmful substances get into the air and spread to big
distances — a lot of people are exposed to its effect;
 On inhalation a large surface of the lungs having many capillaries is exposed to ef-
fect, thus in blood a high concentration of pollutant quickly occurs and blood from the
lungs bypasses liver and spreads in the organism, causing poisonings;
 Except for direct negative effect on a human organism, the atmospheric pollution
renders an indirect negative effect on health and living conditions of the population.
Types of Hygienic Standards in Atmospheric Air
By their effect on organism the atmosphere pollutants are subdivided into 3 groups:
 Substances of the reflex (irritating) action
 Substances of the absorption (toxic) action
 Substances of the reflex-absorption action
There are 2 types of maximal permissible concentration of atmosphere pollutants:
 Maximal–single permissible concentrations (MPC m.s.) are designed for a 20-30-
minute effect of irritation pollutants and directed at prevention of reflex reactions and
poisonings in people at high concentration of pollutants in air (emergencies). They
are established by irritating action on mucous membrane of the eye and by toxic ef-
fect. For toxic substances such researches are carried out on animals with transfer of
the data on a human being.
 Daily average maximal permissible concentrations (MPC d.a.) are designed for
absence of pathological changes in people at a twenty-four-hour effect during the
whole life, and also for absence of remote effects in the subsequent generations.
MPC d.a. is much lower than MPC m.s. in view of greater exposure (time) to effect.
The criteria of harmful effect at normalization of pollutants in atmospheric air are as fol-
lows:
 organoleptic (determining the threshold concentration of pollutant by change of
smell, colour, transparence of air);
 reflectory (establishing the threshold concentration by irritating olfactory effect on a
human or laboratory animal);
 toxicological (threshold concentration is established by common toxic, specific or
remote effects at inhalation on laboratory animals).
Normalization of Pollutants in the Air of a Working Zone
Air of a working zone is the air of industrial and other premises, which pollution affects
the workers. At normalization the term of effect is estimated for 40-50 years (the maximal work
experience), therefore the maximal permissible concentration of pollutants in the air of a work-
ing zone is a bit higher than the maximal permissible concentration in the atmospheric air. At
normalization of substances in the air of a working zone the possibility of the skin-absorptive
effect on organism is also studied in experiments on animals.
Normalization of Harmful Substances in Reservoir Water
Normalization of pollutants in water depends on type of water use, i.e. drinking, house-
hold, recreational, balneological, industrial, fishing, meliorative, transport. Depending on type of
water use, various criteria of harm action are applied, therefore the maximal permissible con-
centration for the same substance can differ considerably. Hygienic standards are established
for first four types of water use.
At hygienic normalization of substances in reservoir water the following 3 signs of harm-
ful effect are studied:
 organoleptic (threshold concentrations changing organoleptic properties of water)
 common sanitary (threshold concentrations affecting the saprophytic microflora,

19
oxygen regulations of reservoir, providing the processes of autopurification of reser-
voir from pollution)
 toxicological (determination of threshold and non-effective concentrations of sub-
stance in experiments on animals as for toxic, specific and remote effects).
Hygienic Normalization of Harmful Substances in Foodstuffs
As standards of pollutants in foodstuffs the MPC and MPL (maximum permissible —
level — for pesticides in foodstuffs) are used. For substantiation of MPC in foodstuffs very diffi-
cult researches are required, that is why maximal permissible concentrations are established
only for few substances for the time being.
The characteristic feature of normalization of pollutants in foodstuffs is that MPCs are
established in view of PDD value (permissible daily dose of harmful substance entering the or-
ganism), thus the entry of pollutant into organism not only with foodstuffs, but also with drinking
water and air are taken into account.
Signs (Criteria) of Harmful Effect at Normalization of Pollutants in Foodstuffs
 Organoleptic — effect on organoleptic properties of foodstuffs;
 Hygienic — maintaining the nutritional value, i.e. major nutrients — proteins, fats, vi-
tamins, etc.;
 Technological — transformations of pollutant at culinary (thermal) processing of
product, the formation of more toxic metabolites;
 Toxicological — studying toxic, specific and remote effects at introduction into labor-
atory animals.
Hygienic Normalization of Exogenous Chemical Substances (ECS) in the Ground
ECS are substances of anthropogenic origin, purposely (pesticides, fertilizers) or acci-
dentally (heavy metals, mineral oil, etc.) brought to the ground by a person.
The ground is a burial place of waste products and at normalization of ECS it is neces-
sary to keep processes of autopurification, and also to prevent pollution of subsoil waters and
atmospheric air.
Maximal permissible concentration of ECS in the ground is such content of pollutant
in the ground, which at direct contact with a human organism (work on the ground) or at migra-
tion on ecological chains guarantees absence of negative effect on a human health, does not
disturb the processes of ground autopurification and does not influence the sanitary living con-
ditions of the population.
The Basic Signs of Harmful Action at Normalization of ECS in the Ground
 Organoleptic — change of organoleptic properties of air, subsoil waters, vegetable
foods contacting with ground, containing various concentrations of normalized sub-
stance.
 Common sanitary — effect on the ground microflora and processes of its autopurifi-
cation.
 Phytoaccumulative (translocative) — accumulation of normalized substance in
vegetable foods (not higher than maximal permissible concentration for foodstuffs).
 Air-migratory — evaporation of substance in atmospheric air above the ground (not
higher than MPC for air)
 Water-migratory — accumulation of substance in subsoil waters (not higher than
MPC for water).
 Toxicological — by toxic, specific and remote effects on laboratory animals at skin or
inhalation action together with a soil dust.

20
Hygienic Estimation of Objects of the Environment at Combined Pollution
In a real life a human organism is affected, as a rule, not by a single but by a number of
harmful factors and their combined effect may considerably differ from a separate effect of
each factor. The following types of combined effect are distinguished:
 A combined effect is a simultaneous action on organism of some factors of identical
nature, for example, only physical (noise and vibration), or only chemical (chemical
substances).
 An associated effect is action on organism of some factors of different nature, for ex-
ample, chemical materials and radiation effect.
 A complex effect — a harmful factor affects the organism in different ways simulta-
neously (for example, with inhaled air, nutrition, water, penetrates through skin).
Types of Combined Effect of Chemical Substances on the Organism
 Antagonism (less than an additive action) — mutual weakening of toxic effects of
poisons at combined action on organism. It has a chemical (mutual destruction of
poisons) or functional nature (different influence on functions of organs and systems).
 Summation (additive action) — an arithmetic addition of separate toxic effects.
 Potentiation (more than an additive action) — a mutual sharp increase of toxicity of
each toxin at combined action.
Rules of Sanitary Estimation of the Environment at Combined Pollution
1. In case of antagonism at combined effect the estimation of environment (water, air,
etc.) is carried out by comparison of concentration of each revealed substance with its MPC
separately. Estimation of the object is given by formula:
C / MPC < 1,
where
C — concentration of revealed substance,
MPC — its maximal permissible concentration in the given object of the environment.
2. At summarizing the combined effect the estimation of the environment is carried out
according to the formula of summational toxicity (Аveryanov‘s formula):
where
C — concentration of the revealed substances,
MPC1 MPC2 MPC3 — their standards
3. In case of potentiation in the above-stated formula 1/К is taken instead of 1 (K —
factor of potentiation, i.e. how many times is toxic effect amplified at combined effect in com-
parison with separate effect of each poison).
where К — an increasing coefficient (factor of potentiation)

21
Hygienic Normalization of Biological Factors in the Environment
To such factors in the environment the following refers:
 Pathogenic organisms of infectious or invasive nature — bacteria, viruses, hel-
minthes, protozoa or their toxins
 Allergens of biological nature
Main Principles of Normalization of Microbe Pollution of the Environment
 Absence of causative agents of infectious diseases in certain volumes or amounts of
the environmental object.
 Substantiation of allowable content of microorganisms in objects of the environment
at which they are considered safe in the epidemiological respect.
 Use at normalization of indicative (sanitary-indicative) microorganisms.
The indicative principle of normalization of microbes in the environment, offered more
than 100 years ago by R. Koch, up to now remains a leading principle of normalization of mi-
crobe environmental pollution.
On choice of sanitary-indicative microorganisms as indicators of pathogenic micro-
bes the following is taken into account:
 Commonplace of dwelling in a human organism
 Identical ways of entering the environment and a human organism (ways of transfer)
 Higher survival rate in the environment in comparison with pathogenic microbes,
higher resistance to disinfection
 Harmlessness for a human being (inability to cause infectious diseases)
Now as an indicator of virus pollution of the environment bacteriophages of colibacillus
(E.coli) are used. By structure, survival rate, resistance they are similar to enteroviruses, caus-
ing intestinal infections.
Various sanitary-indicative microorganisms for estimation of various objects of the envi-
ronment were offered, for example, for reservoir water — bacteria of Escherichia coli group
(BECG), coli-phages.
The quantitative evaluation is made by coli-index — quantity of BECG in a certain vo-
lume of sample and by coli titer — volume of sample in which one BECG is found out.
For example, for drinking water coli-index is up to 3, coli titer is more than 300 ml, in se-
wage coli-index — up to 1,000, coli-phages — up to 1,000, absence of pathogenic microbes in
1 L of water (Table 6).
Table 6
Bacterial Standards in Objects of the Environment for Water Estimation
Kind of water Coli-index Coli-phage Absence of patho-
genic viruses in vo-
lume of water
Drinking < 3 - 10 L
For bathing < 1000 < 1000 in 1 L 1 L
Sewage after cleaning < 1000 < 1000 in 1 L 1 L
Sanitary Estimation of Microbe Air Pollution
The indicative parameter of microbe air pollution of premises is a common microbe
number (CMN) — quantity of microorganisms per m3 of air, a parameter of direct epidemiologi-
cal danger — quantity of haemolytic streptococci per m3 of air. The criteria of estimation of bac-
terial pollution of premise air is given in Table 7.
Special requirements to microbe air pollution are established for operating-rooms, ma-
ternity wards for prevention of intra-hospital infections, postoperative complications (see Table
8).

22
Table 7
Bacterial Standards in Objects of the Environment for Estimation of Premise Air
Quality
of air
Common microbe num-
ber per m3
Amount of haemolytic streptococci
per m3
Clear < 2000 < 10
Satis-
factory
clear
2000 — 4000 11 — 40
Low
polluted
4000 — 7000 40 — 120
Polluted > 7000 > 120
Table 8
Bacterial Standards in Objects of the Environment for Estimation of Operating-Room Air
Time of definition Total microbe number per
m3
Amount of golden staphylococci
per m3
Before operation < 500 0
During operation < 1000 < 4
For estimation of bacterial pollution of ground coli-titer, Cl. Perfringens titer, amount of
helminth eggs per kg are used.

23
Effect of the Environment Quality on the Population Health
Now it is conventional that the integrated criteria of quality of environment (degree of
contamination) is the health of the population. It is used at social-hygienic monitoring environ-
ment of the country.
The Concept of "Health of Population"
Paradoxical though it may seem, but there is no universal definition of concept "health"
up to now.
In medicine and hygiene most frequently the concept of health is used as an average
statistical value characterizing a health state of a certain population, being in identical socio-
economic and ecological conditions.
The border between health and illness is the so-called a 95 % confidence interval — in
a healthy person all the investigated parameters should range within the limits, characteristic of
95 % of people of the given population.

24
Factors Determining Health of Population
If the whole complex of factors influencing health of the population is taken for 100 %,
they are distributed in the following way:
№ Name of the factor Specific Gravity in
%%
1. Lifestyle and social-
economic conditions
49-53 %*
2. Genetic factors 18-22 %
3. Pollution of the environ-
ment
17-20 %
4. Medical factors
(quality of medical aid, devel-
opment of network of public
health services, etc.)
8-10 %
Note: * — oscillations in different countries
According to various data, the occurrence of 70 % of all diseases, 60 % of defects of
physical development and more than 50 % of death cases are caused by environmental pollu-
tion.
Types of Effect of the Environmental Quality on Health of Population
Types of Effect of the Environmental Quality on Health of Population
Direct Negative Effect: Indirect Negative Effect
1. Acute effect: Specific, Nonspecific
2. Chronic effect: Specific, Nonspecific
3. The specific and remote effects
 Direct Negative Effect:
 Acute effect:
 Specific effect — in people sharp specific intoxications occur due to effect of big
concentrations of certain pollutants;
 Nonspecific (provoking) effect (toxic fogs-murderers in London, photochemical
smog of a Los-Angeles type, attacks of bronchial asthma during great air pollu-
tion);
 Chronic effect:
 Specific — accumulation in the environment of small amounts of stable pollu-
tants, causing specific ecologic pathology:
 "Itay-itay" disease (in translation from Japan ―it hurts — it hurts‖) — it was first
described in prefecture of Tokyo. Characterized by myalgia, albuminuria, glau-
coma, dystrophy, spontaneous crises; in 12 years death occurs. Its reason is
accumulation of cadmium compounds in the ground, water, fish and by trophic

25
chains it gets into a human organism;
 Minamata disease — a neurologic disorder caused by methyl mercury intoxi-
cation; first described in the inhabitants of Minamata Bay, Japan, resulting from
their eating fish contaminated with mercury industrial waste. Characterized by
peripheral sensory loss, tremors, dysarthria, ataxia, and both hearing and vis-
ual loss.
 Usho disease (oil illness) — it was also first found in Japan. Characterized by
dimness of the skin, rash, affection of eyes and internal organs; the remote ef-
fects are mutagenic, embryotrophic, cancerogenic. The reason is accumulation
in the environment of polychlorinated compounds containing dioxines — the
extremely toxic and stable substances.
 Endemic diseases (fluorosis, etc).
 Chronic nonspecific effect of biosphere pollution on health — deterioration of all
parameters of health of the population, nonspecific diseases, their aggravation,
etc.
 The specific and remote effects of pollution of biosphere. Allergenic, gonadotrop-
ic (specific), embryotrophic, teratogenic, mutagenic, cancerogenic, immunodepres-
sion effects of environmental contamination which occur in population many years af-
ter pollutant effect or in the subsequent generations.
 Indirect Negative Effect:
The indirect negative effect of pollution is marked by influence on health or living condi-
tions of the population through ecological interrelations in nature (for example, at pollu-
tion of atmosphere the level of ultra-violet irradiation decreases causing growth of rickets
in children; acid rains result in destruction of crop, transition of pollutant from one object
of environment to another, etc.).
Degrees of Biological Response of a Human Organism to the Effect of the Polluted Envi-
ronment
These include:
 death — 1 level of respouse
 disease — 2 level of respouse
 functional signs of illness without symptomatology (prepathology) - 3 level of resp-
ouse
 functional shifts of unknown etiology (tension of adaptive opportunities) - 4 level of
respouse
 asymptomatic accumulation of pollutant in a human organism - 5 level of respouse
Basic Parameters of Population Health and their Use for Studying Influence of the Envi-
ronmental Pollution
 Sanitary-demographic parameters: death rate, birth rate, life expectancy, etc. For
studying the effect of the environment quality they are seldom used because changes
are revealed in a long time, not less than 10 thousand of population and data for not
less than 10 years are necessary for research.
 Parameters of morbidity (sickness rate) are the basic parameters for research of
this problem; it is important to study not the common sickness rate, but that in sepa-
rate groups of diseases.
 Parameters of physical development are especially important in children and tee-
nagers. It is a rather sensitive parameter of the environment pollution that is eluci-
dated in researches of our department carried out in ecologically different regions of
the Crimea.
 Parameters of invalidity: the total amount of invalids per 100 thousand people ac-
cording to groups of physical disability and reasons of physical disability. These are
seldom used for estimation of quality of the environment but more often — for general
characteristics of health state of the population as they largely reflect the effect of
professional harmful factors.

26
Methodical Approaches to Studying the Influence of the Environmental Quality on
Health of the Population
There are a lot of approaches to studying this problem. They include:
 Traditional approach — researches proceed from pollution of the environment to health
of the population. Here 2 main concepts are distinguished:
 A factorial sign X — the factor(s) of the environment which action on health is being
studied;
 An effective sign Y — the parameter (s) of the population health.
There are 4 basic methodical schemes of researches:
Scheme 1: (X > Y) — studying influence of one factor of the environment on one para-
meter of health;
Scheme 2: (X > Sum Y) — effect of one factor of the environment on a complex of para-
meters of health;
Scheme 3: (Sum X > Y) — effect of complex of the environment factors on one parame-
ter of health;
Scheme 4: (Sum X > Sum Y) — effect of complex of factors on a complex of parameters
of health.
 Nontraditional (inversion) approach has been used more often recently, especially
abroad. A way of researches is from a health state of the population to revealing the
most substantial factors of the environment determining the level of health with the pur-
pose of their elimination or minimization.
Concept of Observation (Research) Zones
A very important moment at carrying out researches is a correct choice of such zones; it
is possible to decrease the level of effect of other factors (socioeconomic, demographic, medi-
cal, etc.) on health of the population.
Zone of observation is a certain territory in which the effect of ecological situation on
health of the population is studied.
At carrying out researches it is necessarily to choose 3 zones of observation:
 Experimental zone — territories in which the environmental pollution in accordance
with the investigated factor (complex of factors) essentially exceeds MPC
 Control zone No. 1 — territories where pollution is at a level of MPC
 Control zone No. 2 — territories where pollution is much lower than MPC or absent at
all.
Rules of Choice of Observation Zones
The chosen zones of observation should be identical as for the following parameters: 1)
socioeconomic conditions and lifestyle of population, 2) sex, age, professional structure of
population, 3) number of population.
These zones should differ only in levels of environmental pollution.
Key Questions:
Concepts of ―environment‖ and ―biosphere‖, their basic objects.
 Basic sources and factors of the environment pollution. Classification of adverse fac-
tors in hygiene and ecology.
 Criterion of estimation of the environment quality and types of monitoring of its pollu-
tion (analytical, medical, ecological).
 Concept of hygienic regulations of pollutants in the environment, basic principles of
hygienic standardization.
 Features of hygienic standardization of harmful factors in various objects of the envi-
ronment. Limiting attributes of harmful effect.
 Hygienic standardization of biological pollutants in the environment.
 Hygienic estimation of objects of the environment at simultaneous pollution by vari-
ous substances.
 Basic parameters of population health and their use for monitoring the environment

27
quality.
 Factors of effect on health of the population.
 Types of direct and indirect effect of the environmental pollution on health of the pop-
ulation (acute and chronic effect, remote consequences).
 Methodology and methodical schemes of studying the environmental effect on health
of the population.
 Rules of choice of observation zones for research of effect of the environment quality
on health of the population.
Self-control Test
1. A quantitative parameter of the environmental factor which is safe for maintaining the
ability to life of the man and for population health, and for future generations is
called
* A. Hygienic standard
B. Hygienic factor
C. Sanitary standard
D. Level of safe effect
E. Parameter of the minimal safety
2. A parameter of harmful action, which at establishment of the hygienic standard has
received the minimal concentration (doses) at its action on organism or environ-
ment in comparison with other parameters of harmful action is called:
* A. A limiting parameter
B. A leading parameter
C. A common parameter of sanitary safety
D. A sanitary parameter
E. A hygienic parameter of adverse effect
3. As a level of harmful action of adverse factor on organism, which is determined as
minimally acceptable at establishment of its hygienic standard, is:
A. Accumulation of pollutant in organs and tissues which will not cause any physiological
or biochemical changes in their functional condition (V level)
B. Mortality of organism (І level)
C. Specific disease (ІІ level)
D. Non-specific signs of pathological changes (ІІІ level)
* E. Temporary and partial physiological changes of unknown origin (ІV level)
4. The features of hygienic standardization of the environmental factors based on the
so-called non-line-parabolic dependence of biological effects on dose are:
A. Determination of at least two hygienic standards (level of useful and harmful effect)
B. Determination of at least one hygienic standard (level of harmful effect)
C. Determination of at least one hygienic standard (level of useful effect)
* D. Determination of least two hygienic standards (level of safe and harmful effect)
E. Determination of two and more hygienic standards (useful, minimally safe and harmful
effect)
5. The excess of MPC of toxic substance in the atmospheric air makes up 100. What
changes in the health state of population should be expected?
* A. Severe poisonings
B. Expressed physiological changes in organs and systems
C. Increase of specific and non-specific morbidity
D. Change in health state according to separate functional parameters
E. Fatal poisonings among children
6. The pollutant of atmospheric air refers to the class of extremely dangerous sub-
stances. What is the most probable effect of this pollutant?
* A. Cancerogenic effect
B. Irritating effect

28
C. Neurotropic effect
* D. Embryotropic effect
E. Allergenic effect
7. The hygienic normalization of a harmful factor in the environmental object is:
* А. Such level of the given factor in the environment which does not cause any patholog-
ical changes in organism during the whole period of effect
В. Such level of the given factor in the environment which causes pathological changes in
organism during the whole period of effect
С. Such level of the given factor in the environment which causes prepathological
changes in organism during the whole period of effect
D. Such level of the given factor in the environment which causes functional changes in
organism at the end of effect
Е. Such level of the given factor in the environment which does not cause irreversible
changes in organism during the whole period of effect
8. To hygienic standard of the permissible content of harmful substance in reservoir wa-
ter the following refers:
А. MPL (maximal permissible level)
В. MPD (maximal permissible dose)
* С. MPC (maximal permissible concentration)
D. MAL (maximal allowable level)
Е. MAD (maximal allowable dose)
9. Identify a correct concept of "health" by WHO from the point of view of the individual
theoretical approach.
A. Condition of a human organism, at which it is capable to carry out the biological and
social functions
B. Condition of a human organism, when all its functions are counterbalanced by the en-
vironment
* C. Condition of complete social, biological and psychological well-being of the man (si-
multaneously with absence of illness or physical defects in him)
D. Conditional statistical concept, which is fully characterized by a complex of demo-
graphic parameters, morbidity, physical development, physical disability
Е. Interval, within the framework of which the fluctuation of biological processes keeps
organism at a level of a functional optimum
10. Identify the major factors determining the condition of population health.
* A. Social, economic, genetic, ecological factors
B. Qualitative structure of nutrition, morbidity, mortality, birth rate
C. Geographical position, climatic features, urbanization
D. Ethnical factors
Е. Level of lethality
11. What parameters of population health are primarily worsened under the influence of
the environmental pollution?
A. Demographic
* B. Physical development of children
* C. Morbidity
D. Disability
Е. Quality of emergency care to population
12. To ecopathology of population the following refers:
A. Diseases which most badly yield to treatment
* B. Diseases caused by ecological factors
C. Diseases most frequently encountered in the given district
D. Diseases with a latent course
Е. Diseases affecting the majority of population

29
MUNICIPAL HYGIENE
Theme No 3.
Hygienic Requirements to Microclimate
Concept of Climate and Microclimate
Climate is a complex of average physical parameters of a surface atmosphere in
significant area (region, country, etc.), such as meteorological, synoptic, heliogeophysical.
Microclimate is estimated by physical parameters of air in a small area (a quarter, street)
or in premises.
Major factors of microclimate are temperature, humidity, speed of air movement,
atmospheric pressure (the latter does not vary greatly in premises, therefore it is usually not
taken into account at estimation of microclimate).
Influence of microclimate on a human organism
Microclimate basically affects the thermoregulation system of a human organism.
Thermoregulation system of a human organism may be of 2 types: chemical (heat
production) and physical (heat emission), in a healthy person they are in a dynamic balance.
System of Thermoregulation
It consists of chemical thermoregulation Q1 (thermogenesis) and physical
thermoregulation Q2 (heat emission). Q1 = Q2
System of Thermoregulation
Chemical Thermoregulation
(Thermogenesis)
Physical Thermoregulation (Heat
Emission):
1. Heat conduction (30-40 %)
2. Heat evaporation (10-15 %)
3. Heat radiation (40-45 %).
Chemical Thermoregulation (Thermogenesis)
This is heat formation in the body due to biochemical processes, its level being
determined by the basal metabolism. In a healthy person the level of heat production basically
depends on air temperature (Т)* (through thermoreceptors in the skin and centers of
thermoregulation in CNS). A zone of indifference has the temperature of 15-25º С. If the
temperature is below 15 ºС, the increase of heat production takes place, if above 25 º С — the
decrease of heat production; at over 35 ºС there may be disturbance of thermoregulation
(thermal fatigue, thermal feet edema, thermal emaciation , heat cramps, heat shock, thermal
syncope).
Physical Thermoregulation (Heat Emission)
There are three ways of heat emission:
 Heat conduction (30-40 %)
 Convection — emission of heat to the air (it depends on Т, Е, V)*.
 Conduction — emission of heat to objects (it depends on Т of object, its thermal
conductivity and area of contact with an object).
 Heat evaporation (10-15 %) — it occurs on perspiration and depends on Т, Е, V of the
air.
 Heat radiation (40-45 %). It depends on radiation temperature, i.e. the difference

30
between temperature of environmental objects and a body temperature (36.6 ºC).
_____________________________________________________________________
*Note: Т — temperature, Е — humidity, V — speed of air movement
In normal conditions (in rest) a person loses 30 % of heat due to heat conduction, 15 %
— heat evaporation and 55 % — heat radiation.

31
Types of Thermoregulation Disturbance in Hot Climate
These include thermal emaciation, thermal hypostases of legs, thermal emaciation due to dehydration
and desalination on perspiration, heat spasms, heatstroke, thermal fainting. (See Theme No 25 in the
end of the textbook).
Table 25
Standards of Microclimate for Different Premises and Methods of its Estimation
Factor of microclimate Kind of premise Norms
Temperature of air
Devices: thermometers,
thermograph
Habitable rooms
Sports halls
Operating-rooms
18-22˚С
16-18˚С
22-25˚С
Air humidity
Devices: psychrometer,
hygrometer
Habitable rooms
Operating-rooms
40-60 %
up to 55%
Speed of air movement
Devices: anemometer,
catathermometer
Habitable rooms
Child institutions
0.2-0.4 m/sec
0.07-0.1 m/sec
Air Temperature
The optimal temperature range for any premises (rooms) is 18-22ºС, for sports halls —
16-18˚С, for operating-rooms — 23-25°С (prevention of postoperative complications from cold
are necessary, because in patient under narcosis the centers of thermoregulation do not work).
Fig. 9. Instruments and methods of taking air temperature
The instruments for taking air temperature are called thermometers.
Thermometers may be: household, minimal and maximal.
The household thermometer shows temperature at the given moment, it does not fix
the temperature.
The minimal thermometer fixes the lowest temperature for a certain period. The minimal
thermometers have a capillary with alcohol inside.
The maximal thermometer fixes the highest temperature for a certain period. The
maximal thermometers have a capillary with hydrargyrum inside. The medical thermometers
are maximal thermometers.
Rules for Taking Air Temperature in a Room

32
 Taking air temperature horizontally.
The temperature of air is taken at a height of 1.5 meters above floor level in five
points. The first, second, third, fourth points are the four corners of a room. The fifth
point is in the centre of a room. The odds between measurements of air temperature
in these points should be not more than 2º С.
 Taking air temperature vertically.
The temperature of air is taken in the centre of a room at a height of 0.1 meter above
floor level (at a level of man‘s feet) and 1.5 meters above floor level (at a level of
man‘s respiratory organs). The odds between measurements of air temperature in
these points should be not more than 2.5º С.
 Taking air temperature within a day.
 The temperature is taken in a room in the morning, afternoon, evening and
night. The odds between these measurements should be not more than 5º С at
local heating (fireplaces, furnace). The odds between these measurements
should be not more than 3º С at central heating (radiators of central heating).
Fig. 10. Thermograph
The purpose of this device is determination and recording of fluctuations of air tempera-
ture within time.
Design and principle of its work:
 A perceiving part — a temperature sensor: it presents a bent bimetallic plate
consisting of 2 metals having various temperature coefficients. At fluctuations of
temperature the radius of plate curvature changes, that is transferred to the
pointer with the help of lever system including the driving mechanism — lever,
rod, regulator, axis.
 A recording part: the pointer, which has a writing point on one end, registering
on a tape having an hour and day scale of temperature changes.
 Drum with an hour mechanism. The tape is reeled up on a rotating drum; the
drum can make a complete revolution for one day (daily) or for one week (week-
ly).
Thermograph provides continuous registration of air temperature in a range of +45 - -55º
С with accuracy of ±1º.
Humidity of Air

33
The following types of humidity are distinguished:
 Absolute — the amount of water vapours in the air at a given moment (g/m3 or
mm/Hg);
 Maximal — the greatest possible saturation of air with water vapours at a given
temperature,
 Relative = absolute/maximal in %.
The norm of air humidity is 40-60 % (30-70 %); at a lower humidity dryness of skin and
mucous membranes are observed, at a higher humidity the disturbance of heat emission takes
place. In operating-rooms the humidity should be not more than 55 % in order to prevent the
explosion of ether-air mixture).
Devices for Measurement of Air Humidity
Fig. 11. August’s Psychrometer
Fig. 12. Assman’s Psychrometer
(Aspirational)
Estimation of air humidity. It is necessary to moisten the thermometer with water, to
start the fan with a key, to hang up the device on a support at a distance of 2 m above the floor.
The device can also be used at negative temperatures, but not lower than –10ºС. In 4-5
minutes write down the indications of dry and damp thermometers. As from the surface of a
mercury ball of the damp thermometer the evaporation of moisture and absorption of heat oc-
cur, it will show a lower temperature.
Calculation of absolute humidity is done by the formula:

34
A — absolute humidity;
f — maximal pressure of water vapours at temperature of damp thermometer;
0.5 — constant psychrometric coefficient (amendment to speed of air movement);
t — temperature of the dry thermometer;
t 1 — temperature of the damp thermometer;
Н — barometric pressure;
755 — average barometric pressure.
The maximal pressure of water vapours at t° of damp (f) and dry (F) thermometers is de-
termined by the tables.
Relative humidity (R) is calculated by the formula:
R — relative humidity;
A — absolute humidity;
F — maximal humidity at temperature of the dry thermometer.
Speed and Direction of Air Movement
The normal air speed is 0.2-0.4 m/sec (according to sensations of a person), in a day
nursery — up to 0.1 m/sec (prevention of colds).
Air speed is measured by an anemometer if the speed is more than 1 m/sec, or by a ca-
tathermometer if is less than 1 m/sec according to Hill‘s formula.
For investigation of direction of air movement in open places weather-vanes are used.
The construction of wind rose, i.e. a graphic representation of primary direction of air move-
ment in the given area is very important at location of various objects.
Devices for Estimation of Air Movement Speed
Fig. 13. Anemometer

35
A large pointer goes around a dial having 100 divisions, indicating meters; small pointers
move around a dial having 10 divisions and showing hundreds, thousands, tens of thousands
and more meters. Each small pointer at a complete revolution shows 10 times larger values
than the previous pointer; for example, the transition of the first small pointer to one division
(100 m) is equal to a complete revolution of a large pointer; the transition of the second small
pointer to one division is equal to a complete revolution of the first small pointer, etc.
On observation a person faces a wind and establishes the device in such a way, that the
dial should face the observer. The indications of pointers are written down (a large pointer is
established on zero), then the scales should rotate idle for 1-2 minutes, and after that the coun-
ter of anemometer is switched on, simultaneously with a stop-watch. In 10 minutes the counter
is switched off and new indications of pointers are written down. The difference in indications
between the number of meters passed by air flow for the period of observation is found out.
The obtained number of meters is divided into amount of seconds of the anemometer work.
Fig. 14. Katathermometer
Very weak air flows are determined with the help of katathermometer (cylindrical or
spherical), representing a special spirit thermometer with a scale of 35-38º or 33-40º.
At first the cooling ability of air is determined. For this purpose a katathermometer is put
into hot water (about 80ºC) and heated up until the spirit rises up to half of top expansion of a
capillary. After that the device is wiped and hung up on a support or held on the outstretched
arm in place of investigation, protected at that from effect of sun energy by means of a small
screen (cardboard, plywood). Then, keeping an eye on the stop watch, it should be found out,
how much time it takes the spirit to go down from 38 to 35º; the experiment is repeated twice
and the average value is calculated.
CAA (cooling ability of air) is estimated by the formula:
Н = F/t (mCal per second/cm2),
where F — a katathermometer factor (it is indicated on the back side of each device),
t — time of cooling a katathermometer.
Knowing CAA, the speed of air movement is calculated according to the Hill‘s formula:

36
where Н — the cooling ability of air;
Q — difference between a body temperature of the man (36.5º С) and temperature of a
premise; 0.2 and 0.4 — empiric factors, Х — speed of air movement in m/sec (for small speeds
up to 1 m/sec).

37
Atmospheric Pressure. Devices for Estimation of Atmospheric Pressure
Fig. 15. Barometer
A barometer consists of a vacuum metal box with elastic wavy walls. The fluctuations of
atmospheric pressure have an effect on capacity and form of the box, which walls are flexed
inside at increase of pressure, and are straightened at decrease of pressure. With the aid of a
spring and system of small levers these changes are transmitted to a pointer moving around a
dial, on which the divisions corresponding to a scale of a mercury barometer are marked. The
figures of the scale designate hundreds and tens millimeters mercury; units are counted by in-
termediate divisions of the scale. Before readout it is necessary to knock cautiously on the de-
vice glass to prevent friction of the metal transmission parts. On the dial there is also a ther-
mometer, which indications should be written down.
Metal barometers are less precise than mercury ones, but they are portable and conve-
nient in application. Some of them have the second pointer for indicating pressure at a given
moment.
Fig. 16. Barograph
For continuous observation of fluctuations of atmospheric pressure a self-recording de-
vice — barograph is used, which sensor part is composed of a number of aneroid boxes con-
nected with each other. At change of pressure these boxes move, that is transferred by the
system of small levers to the pointer with a writing point rotating with the speed of one com-
plete revolution per week. All components of the device are placed in a case, which opens only
at change of tapes.

38
Methods of Complex Estimation of Microclimate
The main goal is a complex estimation of microclimate according to one parameter.
Several methods of microclimate estimation are distinguished.
Catathermometry
This method was offered by American scientist Hill in 1916. It is based on speed of cool-
ing a heated body depending on 3 factors of microclimate. A catathermometer is a model of a
human body heated up to 36.6°C. The cooling ability of air (H) is determined by the formula:
H = F / t (millicalories/cm2/sec)
(F — factor of catathermometer — a specific heat emission, t — time of cooling a cata-
thermometer from 38°C to 35°C in seconds).
The normal H is 5.5-7 mCal/cm2/sec. If this value is less, it is hot and stuffy, if it is higher,
then it is cold. This method is now applied for measuring small speeds of air movement by
Hill‘s formula.
Method of Effective Temperatures (ET)
It was developed for USA Navy (submarines, etc.). The microclimate was estimated by a
thermal state of a person at mass examination of seamen in a special chamber with the follow-
ing parameters of microclimate: Е (humidity) = 100 %; V (speed of air movement) = 0 m/sec;
only the parameter of air temperature was variable.
A comfort zone of thermal state of people upon these conditions makes up 17.2-21.7°
EТ. A line of comfort is 18.1-18.9° EТ.
The effective temperatures are determined by nomograms or tables with the help of in-
dications of dry and damp thermometers and speed of air movement.
The further modification of this method is the method of equivalent-effective tempera-
tures (EEТ). Additional chambers were created where Е (humidity) or V (speed of air move-
ment) changed in such a way that the thermal state of a person corresponded to EТ in a com-
fort zone. As a result tables were developed for automatic air conditioning via computer.
Application of Methods of Complex Estimation of Microclimate
Methods of complex estimation of microclimate are used in the following situations:
 At conditioning premises while staying indoors for a long time — spacecrafts,
planes, submarines.
 In balneology — for dosing air procedures.
 For improvement of hygienic working conditions in hot workshops of industrial
enterprises.
Apart from this, microclimate can be estimated by thermal state of people staying in a
given premise with the help of:
 a questionnaire technique — interrogation of people in a premise about their
thermal state of health — a 7-point scale of heat sensation exists (but many
people are required for examination),
 method of skin (dermal) temperatures by means of electrothermometer:
Table 26
Temperature Temperature of
the forehead skin
(t1)
Temperature of
dorsum of hand
(t2)
t1 — t2 Thermal sensation
10 31.2 24.2 > 6 cold
20 33.5 29.1 3 — 4 comfort
30 35.3 33.1 2.2 hot
35 35.8 35.6 < 1.5 very hot
 Technique of perspiration measurement — by electroresistibility of skin, by

40
Lesson No. 1.
Hygienic Requirements to Factors of Microclimate
Key Questions
1. Concept of climate and microclimate.
2. Hygienic significance of air temperature and rules of its measurement.
3. Hygienic significance of air humidity and methods of its estimation.
4. Hygienic significance of speed of air movement and methods of its estimation.
5. Characteristics of microclimate of hospital wards and operating rooms, and other pre-
mises.
6. Concept of ―wind rose‖, its hygienic estimation.
Learning Objectives and Their Concrete Definition
1. To know devices for estimation of air temperature and humidity. To get acquainted with a
technique of estimation of air temperature and humidity in premises.
2. To know the design and rules of work with devices for estimation of temperature in de-
grees by Celsius: the minimal thermometer; the maximal thermometer; the household
thermometer; the electronic thermometer; thermograph (see Appendixes).
3. The estimation of air humidity is carried out with the help of Assman‘s and August‘s
psychrometer with application of formulas and psychrometric tables.
4. Devices for estimation of speed of air movement. A technique for estimation of air
movement speed in a lecture-room. Design and rules of work with devices for estimation of
air movement speed. Anemometer.
5. Method of construction of ―wind rose‖ and its hygienic estimation.
Concept of "Wind Rose"
Winds blow permanently in atmosphere. The direction of wind may be: northeast, north,
north–west, west, south–west, south, south–east, east. The direction of wind is indicated by a
point whence the wind blows.
Fig. 17. The construction of "Wind Rose"
Example:
Graphic presentation of the primary direction of air movement in a given area is called a
"wind rose". The direction of wind begins in the center of the picture. Points of the wind direc-

41
tion are connected with a line. In this picture the wind blows from the east more often.
Scientists use the "wind rose" at constructing industrial enterprises, hospitals, houses.
Industrial enterprises must be constructed in a town zone where winds blow least of all.
Example:
Where must the industrial enterprises, hospitals, apartment houses be constructed?
Solution
Industrial enterprises must not be constructed in the east of town. They must be con-
structed in other town zones (north-east, west, south). In this case the town will not be polluted
with industrial wastes. Hospitals must be constructed in the east of the town (the cleanest zone
of the town). Blocks of flats must be constructed in the north, north–west, south–west, south–
east, east of the town.
Self Test
1. Which of the following devices are used for estimation of humidity? (More than one answer
may be correct)
*A. Psychrometer
B. Thermograph
*C. Hygrometer
D. Anemometer
E. Wind vane
2. The optimal norm of relative humidity for premises is:
*A. 40-60%
B. 30-70%
C. 10-30%
3. In the classroom on the 5th lesson the following parameters of microclimate have been
found out: temperature — 25°С, relative humidity — 79 %, speed of air movement —
0.1m/sec. What physiological parameters testify to unfavorable effect of microclimate on
a functional condition of the pupils‘ nervous system?
*A. parameters of capacity for work and chronoreflexometry
B. pulse, respiratory rate, vital capacity of the lungs
C. parameters of capacity for work
D. body temperature, chronoreflexometry
4. In which operating room is microclimate for the operating surgeons more favorable?
*A. temperature — 23°C; relative humidity — 40 %; speed of air movement — 0.03 m/sec
B. temperature — 25°С; relative humidity — 45 %; speed of air movement — 0.09 m/sec
C. temperature — 23°С; relative humidity — 40 %; speed of air movement — 0.1 m/sec
D. temperature — 24°С; relative humidity — 30 %; speed of air movement — 0.05 m/sec
E. temperature — 25°С; relative humidity — 50 %; speed of air movement — 0.08 m/sec
5. The relative humidity of air in a hospital ward meets the requirements of hygienic norm.
Choose the optimal value.
*A. 30 — 60 %
B. 30 — 70 %
C. 30 — 80 %
D. 20 — 40 %
E. 20 — 50 %
Problem Solving
1. On inspection of conditions of patients‘ staying in the hospital the following has been
established: the area of a single-bed ward is 6 m2, an average air temperature — 18° C, hu-
midity — 60 %, speed of air movement — 0.18 m/sec. Give a hygienic estimation of microcli-
mate in the ward.
2. In city N. the engineering plant is being constructed. According to a long-term obser-
vation the recurrence of winds makes up (in percentage): N — 14, NE — 5, E — 2, SE- 6, S-
19, SW — 26, NW — 18. Specify the optimal direction of the engineering plant location in rela-
tion to the built-up area of the city.

42
Standard Answers:
1. The microclimate in the ward is satisfactory; all the parameters correspond to the hy-
gienic norms.
2. East, as the recurrence of winds from the east direction was equal to 2 %, that is the
least value.
Lesson No 2.
Methods of Complex Estimation of Microclimate. Types of Disturbance of Thermoregula-
tion in Conditions of Hot Climate
Key Questions
1. Bases of physiology of a human heat exchange and its connection with a microclimat-
ic condition of the environment.
2. Hygienic significance and technique of estimation of organism physiological reactions,
which manifest the condition of the thermoregulation system.
3. Methods of complex estimation of microclimate:
 katathermometry
 effective temperatures;
 equivalent-effective temperatures
4. Application of methods of complex estimation of microclimate.
5. The disorders in a health condition and diseases which occur due to effect of discom-
fort microclimate on the man. Measures of their prevention.
Learning Objectives and Their Concrete Definition
1. Estimation of cooling ability of air (CAA) by method of katathermometry.
For the purpose a katathermometer (see the description in the previous lesson) is
placed into hot water (about 80°C) and heated up until the spirit rises up to half of top expan-
sion of a capillary. After that the device is wiped and hung up on a support or held on the out-
stretched arm in place of investigation, being protected from effect of sun energy by means of
a small screen (cardboard, plywood). Then, keeping an eye on the stop watch, it should be
found out, how much time it takes the spirit to go down from 38 to 35°; the experiment is re-
peated twice and the average value is calculated.
CAA (cooling ability of air) is estimated by the formula:
Н = F/t (mCal per second/cm2),
where F — a katathermometer factor (it is indicated on the back side of each device),
t — time of cooling a katathermometer.
The normal CAA = 5.5-7.0 mCal per second/cm2; if this parameter is lower than the
norm, there will be overheating, if it is higher — overcooling.
2. A technique of estimation of effective temperatures by nomogram.
A total effect of temperature, humidity and air movement are expressed now in degrees
of effective temperature. The indications of dry and wet thermometers of a psychrometer, as
well as data about speed of air movement are necessary for estimation of effective tempera-
ture by nomogram. Having obtained them, the procedure is as follows: points on the right and
left scales of nomogram corresponding to indications of dry and wet thermometers are con-
nected by a line. The place of intersection of this line and the curve of appropriate speed of air
movement gives the value of effective temperature.
Example: The temperature of the dry thermometer of psychrometer is 24С, the tem-
perature of the wet thermometer of psychrometer is 16С. Air speed is 30 m/min. Determine
the effective temperature under these cinditions.
Solution: On the left-hand side of nomogram we find the temperature of the dry ther-
mometer; on the right-hand side of nomogram — the temperature of the wet thermometer. We
superimpose bar on both retrieved points. We see that the bar intersects a curve of air move-
ment speed corresponding to 30 m/min in a point marked by figure 20. This figure will thus be
considered the effective temperature. On the basis of numerous observations the following

43
norms of effective temperatures are distinguished:
a) The zone of comfort is 17.2–21.7 effective temperatures. At these tem-
peratures 50 % of people feel well and comfortable.
b) The line of comfort is 18.1-18.9 effective temperatures. At these tem-
peratures 100 % of people feel well and comfortable.
3. Definition of equivalent-effective temperatures. There is a special table, according
to which we can find out the optimal microclimate for a person at different values of tempera-
ture, humidity and speed of air movement so, that heat sensation of organism is as if in a zone
of comfort.
Algorithm of Practical Work of Students
The first stage. Testing the initial level of knowledge and skills.
The second stage. Active participation in discussion of key questions on the theme of
the lesson.
The third stage. Independent work on estimation of CAA, speed of air movement in a
premise, determination of effective temperatures.
The fourth stage. Solving situational tasks and final testing on the given theme.
Self-control Test
1. Where are the centers of thermoregulation in a human organism?
A. brain cortex
B. hypothalamus
*C. medulla oblongata
D. cerebellum
E. reticular formation
2. What are the devices for estimation of cooling ability of air?
A. psychrometer
B. thermograph
C. hygrometer
D. anemometer
*E. katathermometer
3. Specify the zone of comfort according to effective temperatures (in ° ET):
*A. 17.2-21.7
B.18.0-22.0
С. 20.1-23.5
D.18.0-20.0
E.16.0-18.0
4. What factors influence the intensity of cooling the heated body?
*A. air temperature, air humidity, speed of air movement
B. air temperature, air humidity
C. air temperature, speed of air movement
D. air temperature
E. air humidity; radiation temperature
5. At harvesting grain in July the air temperature outside was 31°С; in the cabin of com-
bine harvester — 35°С, speed of air movement — 0.2 m/sec, relative air humidity
— 55 %, temperature of sides and roof of the cabin — 45 oС. Normalization of mi-
croclimate in the cabin is possible by means of
A. thermal isolation of sides and roof
B. decrease of air humidity
C. increase of air humidity
*D. cooling of the air
E. increase of speed of air movement
6. In patient with pneumonia the body temperature has increased up to 39°С, the skin
integuments have turned pale and become dry, gooseflesh occurred. What distur-
bances of thermoregulation caused these manifestations of fever?
A. dilatation of vessels, increase of perspiration, prevalence of heat production
*B. vasoconstriction, decrease of perspiration, prevalence of heat production

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