This document summarizes the effects of air pollution on human health. It discusses how air pollutants like particulate matter, sulfur oxides, carbon monoxide, and nitrogen oxides can cause respiratory illnesses like chronic bronchitis and pneumonia. Prenatal exposure to environmental chemicals can also harm fetal development. The document outlines methods to study health effects through surveys, exams, and tests. Overall, air pollution is associated with increased deaths from heart and lung diseases as well as acute illnesses, chronic conditions, and reduced lung function.

1. "EFFECTS OF AIR POLLUTIONS ON HUMAN HEALTH"
by
Dr. S.H. Clerk, MD, DPH, DIH(Eng)
Medical Officer (Industrial Health)
Ahmedahad Electricity Company Ltd.
A h m e d a b a d .
INTRODUCTION
The subject has long been a matter of concern, since the
industrialisation of the country brought in Its pollution '
hazards. Pollution of the atmosphere by chemical warfare
and invasion of space by-man are recent developments
which have increased the gravity of the problem.
The pollutants like dust particulates, sulphur oxide, carbon
monoxide, oxidants, nitrogen oxides, lead etc. have now taken
a back seat after the toxic chemicals have taken up a
predominant position.
Toxic chemicals are being exported by the developed countries
to the third world. We are circumventing the problem of
exposure^ toxic chemicals, if we consider that only the
exposed workers are the target of attack. Most of these
hazardous substances would permeate their way to the
opportunity by polluting air or water,. The next generation
is also at risk* as the genetic cocte gets damaged.
Environmental chemicals pose a potential threat to health,
because a large number of people get -exposed to chemicals
that linger in the environment.
Prenatal exposure to the environmental chemicals is more like!
to produce toxicity than adult exposure. For radiation,
methylmercury, lead etc. the unborn child is at"'"greater risk

2. 2
than the adult. Subtle functional deviations In the offsprings of
exposed mother:.- may bo one of the most sensitive indicators of potential
harm from environmental chemicals. The consequences of
prenatal environmental exposures may not be evident till
the advanced age.
Although we all had the mental perception of the whole problem
it lied buried in our mental recesses and red tape till t'ne
methyl isccyn'-'.te disaster in Bhopal industry awakened us
from the slumber. History states that only a industrial
disaster alerts the scientists and the politicians about
the pollution problems.
II. Types of air Pollution:
Three major types of air pollution are recognised:
1. The sulnhur oxide & particulate complex,
2. Photochemical oxidants,
3. Miscellaneous category of pollutants that
arise from industrial point sources.
The first two are permanent inhabitants of metropolitan
towns while the third type varies with the industrial
activity of individual location.
The sulphur oxide component includes sulnhur dioxide, sulphu-
ric acid, and sulphate aerosols. Particulate component
comprises of soot, dust, flv ash, metallic oxides ;f iron
& zinc, silicates, aerosols of sulphates & nitrates and
other compounds.
Photochemical oxidants are formed in the atmosphere from
a complex chemical reaction between solar radiation and
nitrogen oxides & hydrocarbons. Hydrocarbons are emitted

3. from motor vehicles and from other sources such as petroleum
refineries, manufacturers and users of solvents. Photo-
chemical oxidants have four manifest ations:formation of
ozone, acute eye and respiratory tract irritation, specific
types of plant damage and smog. Ozone is often considered
as an index of photochemical oxidants in ambient air,
•Emissions from the industry may be consisting of arsenic, cadmium,
mercury, asbestos, hydrogen sulphide. These days, newer toxic
chemicals form a vital component of the affluents, and which deserve
greater attention.
III. Methodology to study health effects:
A health survey of a sample of population exposed to air
pollution should be undertaken. A control survey is
conducted in a sample of population in a pollution free
area. The sample should comprise of persons of all age
groups, along with sizeable number of school children and
elderly persons. Health survey should Include the following
components.
(A) History -taking: A complete history of each person,
his personal and family history, any Illness in him and
his past and present occupation, any exposure to
dust, chemicals, gases, vapours or fumes at home or
at his workplace, etc. should be recorded in the
prepared questionnaire by^ktructured interview method.
The history should also include particulars of smoking
habit If any, and the number of bidis/cigarettes
smoked per day and the numbers of years of smoking.
(B) Clinical examination: A thorough clinical examination
of the persons has to be done. This would include

4. : H :
i) General examination
il) Examination of the respiratory system
iii) Examination of other systems.
(C) Chest X Ray: : Every person taken for the survey should
be X Rayed. A full sized 12' x 15' sized posterloant-
erior chest X Ray should be taken. 'Chest X Rays should
be read preferably by- a panel of 2-3 specialists, and
any abnormality seen should be recorded.
(D) Laboratory examination ': Routine blood examination
should be done. This comprises of total red cell and
white cell county differential white cell count,
haemoglobin percentage and absolute eosinophil count.
(E) Lung function tests : These tests have to be carried
out on a standard portable spirometer. Three tests,
which are not time consuming are very essential.
These are vital capacity. Forced expiratory volume
(0.75 or 1 sec), and Peak flow rate.
(F) Environmental hygiene studies: I need not go into the
details of these tests, as these shall be dealt with
by others. I would like to •emphasize that these
studies should be done concurrently with the health
studies on population. Air samples should be taken
at the nose level (breathing zone) of the persons and
analysed for different air pollutants.
IV. Effects on health:
IV.1 Deaths
There is an association between sulphur oxide/particulate
air pollution and deaths, in air pollution episodes. Such
episodes have occured in Belgium (1930), in Pennsylvania

5. : 5 :
(19^8), in London (1952, 1962) and in New York (1953).
Excess deaths have been reported among persons suffering
from heart and lung diseases. Deaths were due to bronchitis,
pneumonia, and other lung and heart diseases. Persons over
the age of ^5 were the maximum victims. Some healthy
persons were also affected.
Photochemical oxidants are highly toxic and at low concen-
trations are a respiratory tract irritant. Deaths
exclusively due to photochemical oxidants are not yet
recorded. -No single air pollutant however could be consi-
dered responsible for-the excess of deaths. Investigators
in various countries have reported associations between
residence in heav/JypolIuted areas and deaths from all
causes combined and from bronchitis and other respiratory
causes.
The advent of toxic effluents from the industry is a
recent addition to the list of causes of death. The methyl
isocynate emission in the Union Carbide factory at Bhopal
caused many deaths in the general population. The list of
chemicals and gaseous effluents in the air shall be
increasing every day with the use of such toxic substances
in the industries.
IV.2 Chronic lung diseases:
Chronic obstructive lung diseases like chronic bronchitis,
emphysema, etc. are-reported to be caused by air pollution
exposure. Many studies of chronic lunr disease and air
pollution conducted throughout the world have indicated a
relationship between the prevalence of chronic respiratory
symptoms and the sulphur oxides particulates complex.
Chronic lung disease appears t2 develop in response to
cumulative fasujiz that include smoking intensity,

6. : 6 :
recurrent lung diseases in childhood andvoccupational
dusts. Persons already having a chronic lung disease get
exearberation of symptoms and disease. Studies have shown
that most of the excess deaths and illnesses cccured in
persons who had chronic lung illness before the air pollution
episode. Frequently low temperatures exert a greater effect
than does air pollution and the similar temporal pattern of
air pclution and cold temperature in the past may have
accounted for some of the observed air pollution/disease agg-
ravation relationships. British studies suggest that
improvements in air quality during the past 10 to 15 years
in England have largely abated the relationships between
air pollution and disease aggrevation.
IV.3 Pneumoconiosis (Silicosis)
It may sound rj diculous if one would be told that there
could be a condition called 'Non-occupational pneumoconiosis',
There have been reports of the persons residing near the
desert areas getting exposed to the strong wind carrying
the sand particles continuously for many years, with the
result that the exposed persons suffer from pneumoconiosis
(silicosis) similar to the disease in occupationalv exposed
workers.
IV.4. Bronchial asthma
Asthmatic patients are particularly susceptible to short
terms peak concentrations of air pollutants. Increased
rates of asthma attacks were noted during episodes of
sulphur oxide/particulate and photochemical oxidant air
pollution. It was found that although asthma frequency was
directly related to the lower temperature gradient, air
pollution concentrations still exerted a significant
effect. The asthmatic person appears to represent an
extreme on the scale of respiratory sensitivity to external

7. 7
stimuli. Increased concentrations of air pollution are one
of many factors that may represent attacks in some persons
with asthma. Pollens in the ambient air also precipitate
attacks of bronchial asthma.
IV.5. Acute lung disease
A greater incidence of acute lung disease In communities
with sulphur oxide/particulate concentrations have been
observed. There is a prcbablje association between acute
lower respiratory tract diseases (acute bronchitis, pneumonia,
other acute chest Illnesses) in adults ana air pollution with
sulphur oxide/particulate complex and possibly with nitrogen
oxides .
Rates of acute lung illness in children have been repeatedly
associated with residence in more polluted areas affected by
sulphur oxide/particulate complex. Longitudinal studies of
children conducted in England show an association between
prevalence of cough in young adults and exposure to air
pollution in childhood.
IV.5 Lung function tests.
Lung function tests are considered to be very sensitive
indicators of lung disfunction. These tests are of in-
creasing importance in studying workef-s or population exposed
to dust, fumes, gases and vapours. In U.S.A., even though
the chest X Ray is normal, decreased lung function tests
are considered important for purposes of obtaining ccnpj}jj^-a-
tion for a ocoupational lung ailment. The tw. most important
tests which could be cerried out in the general "population
without any wastage of time are (a) Vital car-.city and .
(b) Forced expiratory volume (0.75 or 1 sec.). If we have
with us the normal values of healthy persons :f different age

8. 8
groups, decrease in these values in the exposed persons is
a sensitive indicator of health effect. These tests are
of particular importance in children. In nearly all
reported studies, children residing in more polluted areas
show diminished values when compared with their counter
parts living in less polluted areas. Improvement in lun.a
function tests in children living in more polluted areas
when air pollution concentrations decreased is significant
in suggesting the reversibility of air pollution effect on
lung function, at least in childhood.
IV.7 Air Pollution and Cancer of the lung
It is well recognised that smoking is a major factor in
the causation of lung cancer. Occupational exposures to
ionizing radiation among uranium miners and to asbestos,
arsenic, chromates, nickle and coke oven fumes are well
established as risk factors for lung cancer. An inter-
national study group in 1977 concluded that whereas smoking
was the predominant cause of lung1
'cancer, combustion products
of fossil fuels in ambient air probably acting together with
the cigarette smoke had been responsible for cases of lung
cancer. Of particular concern are recent reports of
nitrosamines and polycyclic hydrocarbons. Benzopyrene is
the most commonly employed index for atmospheric carcinogens,
particularly for the class of no'lycyclic hydrocarbons. On
the basis of the evidence gathered so far, the suspicion
that air pollution leads to lung cancer remains neither
proved nor disproved.
IV.8 Air Pollution and Heart Disease
Of the known environmental risk factors that contribute
to heart disease, smoking, diet, lack of exercise, hi-^h
blood pressure, and increased lipid concentrations have
received the most attention. Higher rates of case fatality

9. among patients admitted to hospitals for myocardial
infraction have been observed during periods of relatively
increased carbon monoxide pollution. There are other
reports which suggest relationships between exposure to
ozone and damage to myocardial fibres, between exposure to
sulphur dioxide and acardiovascular deaths, and between
sulphate concentrations and exacerbation of disease in
elderly patients with heart disease. Cadmium in large
concentration in the air is also suspected to increase death
rates from heart disease.
IV.9 Effects on the eyes
Some of the air pollutants cause irritation of the mucous
membrance of the eyes and cause lachrymation or watering
of the eyes. These effects are thought' to be temporary,
acute and short term. The person recovers as soon as he
comes out of the polluted zone. At times, the dust
particles enter the eyes and lodge in the conjunctive. Till
now no other eye effects due to air pollution have been
diagnosed and reported. There have been newspaper reports
of blindness or less of eye due to MIC exposure in Bhopal,
but no authentic scientific reports have come forth.
IV.10 Sensory, neurologic and behavioral effects
The odour of some air borne substances and the irritation
to the eyes, nose and throat caused by other pollutants
are the most common and annoying aspects of air pollution
for many persons. Perception of these effects Is very real,
but it is difficult to quantify their perception in
populations. Hydrogen sulphide f
tf ^S) is perhaps the only
material which has an cffensive odour. At concentrations
more thanrar^ppm, H0S may impair the sense of smell and
produce unconsciousness and death. Aldehydes e.^-,.
formaldehyde Irritate the eyes, nose and the respiratory
tract. Ammonia is a strong respiratory irritant. Ozone

10. 10
causes a burning sensation in the upper part of the chest.
Carbon monoxide can alter human performance as well as
cardiac function. Decrements In vigilance tasks have been
observed at relatively low carboxyhaemoglobin saturations
(in blood). Inhalation of significant amounts of air borne
lead can cause neurologic disturbances and even adverse
effects on the nervous system.
IV.11 " Human reproduction including birth defects
The unborn foetus is exposed to the chemical fumes/vapours
through the mother by haematogenous transplacental transfer.
It has been noticed that the chemicals affect not only the
reproductive system of the female but also the male. Carbon
monoxide, tetrachloroethylene, nitrous oxide, lead, cadmium,
mercury, pesticides are already listed and the list is
increasing. It is imperative that we should be concerned not
only of the present generation but ^also of the coming one.
v
- The Action of Air Pollution on The Respiratory System.
V.1 Normal defence of the respiratory system: t
j
Particles: The respiratory system is well endowed with
mechanisms to remove and clear particles. Although a person
breathes 10000 to 20000 litres of air per day, each litre
of which may contain several million suspended particles,
the air that reaches the terminal respiratory unit with
each breath is remarkably cleaned. This cleansing action
is brought about by removal of particles, and clearance
of deposited particles. In addition, there is , immunologici V
defence system, which also comes into force. Removal and
clearance of particles from the respiratory system is as

11. 11
fellows :
Defence mechanism
Site of action
Upper resp-
tract
(nasopharynx'
Removal of particles from
the air stream (particle
deposition).A • . . .. - • ...
Impaction on fine hairs &
in narrow & tortuous
passages of the nosoi
Clearance of deposited
particles
Nose blowing, sneering,
coughing, mucociliary
action, swallowing.
Tracheo-
bronchial
tree
Impaction, sedimentation,
diffusion.
Coughing, mucociliary
action, bronchial blood
flow.
Alveelar zone Sedimentation, diffusion Phagocytosis by macrophage
transepithelial transport
to lymph and blood.
It has been established by Policard, the Dean of French
investigators on Pneumeconiosis, that a French coal minor
during a life time of work of 30 years inhales approximately
6 kilograms of coal dust. Yet his lungs £t death will contain
only 60 grams. 'This means that the lungs are capable of
eliminating 99 percent of the inhaled dust. In other words,
the self cleansing mechanism of the lungs Is 98 to 99 percent
perfect. Now it is that 1 percent deficiency that causes
pneumoconiosis.
Gasesoluble- gases will be absorbed by the air passages,
where they may be^buffered, detoxified by biochemical reactions
diffused into systemic circulation or exert a pathologic effect.
Less soluble gases such as ozone and nitrous oxide pass more deep
into the respiratory tract.
V.2 Sulphur oxide/Particulate complex:
These two pollutants^are discussed as a single pollutant
complex as their increased concentrations are usually found
together in urban areas, and sulphur dioxide (S02) is
transformed into a particulate aerosol. Most suspended
particles range in size from submicronic to 10 Um in diameter.
Sulphur oxide component consists of sulphuric acid, sulphites,
and various metallic, acidic and ammonium sulphates. Combustion

12. 12
of fossil fuel which is the principal emission' source of
the sulphur oxide/particulate complex yields a variety of
chemical compounds including oxides of carbon, iron,
aluminium, sulphur, silicon, and phosphorous as the main
constituents. Increased ambient concentrations of sulphur
oxides and particulates have been consistently associated
with increased deaths during episodes of air pollution,
and with the aggravation of symptoms in persons with heart
and lung disease, lung functional changes and chronic
respiratory disease.
V.3 Photochemical Oxidants
They are formed in the atmosphere from precursor pollutants
(hydrocarbons and nitrogen oxides) with energy provided by
solar radiation. The principal component of photochemical
oxidant mixtures is ozone. The junction between the
respiratory bronchioles (smallest air passages) and alveoli
have been found to be most affected. There is an increasing
frequency of eye irritation, cough, chest discomfort,
breathlessness, as well as decrease in lung function values
due to exposure.
V.H Nitrogen dioxide
Exposure to nitrogen dioxide has been found to have a
significant excess of acute respiratory episodes. There is
also an Increase in the air way resistance in the respi-
ratory system. At high concentrations, maximal effects of
nitrogen dioxide may occur from 1 to 3 days after exposure.
Some epidemiologic data indicate that acute reactions to
complex urban pollutants may occur 1 or 2 days after peak
exposure.

13. 13
Carbon monoxide
Emissions from motor vehicles constitute the largest source
category ford Tnbient concentrations of carbon monoxide.
Carbon monoxide combines with haemoglobin of the blood to
form carboxyhaemoglobin which interfere with the oxygen
carrying capacity of the blood resulting in a state of
tissue hypoxia. Headache, drowsiness, coma etc. may
result from acute exposure. Exposure at low levels may
initiate or enhance myocardial changes, damage the
extrapyramidal system of the nervous system. Such a low
concentration may.have an effect on the nervnus function
principally in a distracting and monotonous situation.
Studies have revealed thatbeh^vi-ural changes occur.
Intelligence is not affected but the judgement is lost.
Other Pollutants of concern to human health
Many industries emit their own characteristic type of
pollution, and a review of this sort cannot adequately
treat such pollutants as vinyl chloride, other cholorina-
ted hydrocarbons, H2S, flourides, tars, arsenic, metal
fumes etc.~~£he use of new chemicals in the industries,
the list of new pollutants is increasing every day and
perhaps in -course of time, the chemicals polluting the
atmosphere would be more in abundance than the usual
pollutants of today.
Lead: Lead as a community air pollutant has been associa-
ted with increased blood lead in adults. There have been
substantially higher concentrations of atmospheric load in
some of the large cities due to large contribution of
motor vehicle exhaust. Important symptoms of lead toxicity
due to air pollution, like anaemia, colic, lead line on the
gums, premature loss of teeth, changes in bone narrow,
tremor, peripheral neuritis, and encephalopathy have not
been reported although there has been evidence of impaired
nerve conduction velocity.

14. : :
V.6.2 Asbestos: There is mounting evidence that general
population may suffer from exposure to asbestos. This
suspicion rests on 3 observations (i) Many persons without
occupational exposure have asbestos fibres in their lungs,
(ii) These fibres appear in the ambient air and (ill) in
some areas, persons without occupational exposure show
pathologic changes that indicate a reaction to asbestos,
In asbestosis, a lung disease, the presenting symptom is
breathlessness. X-Ray picture of chest shows a ground
glass or fine cobweb appearance. Lung cancer, mesothelioma
could occur in persons exposed to asbestos fibres.
V.6.3 Flourides: The systemic effects of prolonged absorption of
flourides from either dust or vapours have long been a
source of some uncertainty. There could be heavy exposure
to flourides in the event of accident or plant failure, as
in the case of Meuse valley disaster. Absorption of excess
of flourides in the body results in flourosis, which is
of three types: 1 Dental: This is found amongst children .
There is mottling of the dental enamel with chalky white
patches on teeth (best seen on upper incisor teeth),.2.
Skeletal: symptoms and tingling sensation in legs/feet, back
pain and stiffness. There is formation of new bone and
calcification of tendons, ligaments and interosseous
membrane. 3. Genu valgum and osteoprosis.
V.6.4 Mercury: Mercury pollution occurs in a variety of forms
from different sources, but the combustion of fossil fuels
accounts for a substantial portion of the atmospheric
contamination. So far there have been no reports of
mercury toxicity, as the concentration of the metal in
the ambient air has been very low. However, one has to
keep vigil on potential hazards due to mercury. Research
Studies on lungs of slaughtered animals in Bihar and

15. 15
Bengal coal fields have shown mercury to be present in
their lungs. Chronic excessive exposure may result in
one or more of the 4 classical signs: gingivitis,
f
tremor, emotional instability and increased salivation,
apart from other symptoms. The most characteristic
symptom is mercurial tremor. It may be lnterruptive
every few minutes by coarse jerky movements. It
usually begins inthe eyelids, lips, and tongue. I
remember, once when In Britain, I was going round along
with Medical Inspector of Factories in the thermometer
factory, we saw a middle aged worker actively at work
but constantly nodding his head. On asking, he
denied having any symptoms, but when examined, he was
„ detected to have early mercury toxicity. His immediate
removal from the work place prevented any further
deterioration.
Toxicity due to organic mercurials is characterised by
ataxia, tremor, dysarthria, impaired bearing, pavesthesia,
restriction of visual fields and emotional instability.
In Japan, methyl mercury poisoning through consumption
of methyl mercury contaminated fish and shell fish
precipitated 'Minamata disease1
. Cats in this district
had died after paroxysmal fits, convulsions, dart like
or circular running ana some-result like movement (the-
disease was thus also termed cat dancing disease),
frequently jumping into the sea and drowning. Infants
born of women exposed to methyl mercury had mental
retardation, spasticity, chronic seizures and
blindness. Mothers had no symptoms. In behavioral
symptoms known as 'erethism' in mercury toxicity, the
man is easily upset and em&assed, loses all joy of life
and lives in constant fear. He has a sense of timidity
and may lose self control before strangers. Drowsiness by
day, depression, loss of memory and insomnia may occur.

16. 16
V.6.5 • Beryllium: It is likely to be an air pollutant iniha,
neighbourhood of industries using it. Inhalation of
beryllium compounds causes distressing cough, breathlessness
followed by X-Ray changes of increased linear markings and
ground glass appearance in lungs. Later the lung lesions
become granular and modular with conglomerate masses.
Diffusion capacity gets impaJJtct.
V.6.6. Cadmium: Air borne particles of cadmium generally
present only a minor source of exposure except in the vicini-
ty of certain high emission sources such as smelters.
Inhalation of cadmium fumes or dust causes respiratory
tract irritation with symptoms of cough, chest pain,
and breathlessness, which may result in bronchitis,
pneumonitis and pulmonary oedema. Chrnnic intoxication
leads to lung emphysema, kidney damage and proteinuria!.
In Japan, inhabitants who absorbed cadmium from water and
„ food suffered from esteomalacia and skeletal deformation.
There was severe body pain and they cried ITAI-ITAI(Ouch-
Ouch).
V.6.7 Organic pesticides : ferial application and evaporation
allow pesticieds to become air borne, and the condensation
of organo-chlorlne vapours from compounds like DDT
orjto colloidal particles enhances their ability to
travel long distances. Communities near agricultural
spraying may have significant exposures. Most prominent
symptoms of toxicity are nausea, vomiting, constriction^,
of the pupils, weakness, dizziness, headache, tachycardia,
increased salvation. In Karnataka, harljans consumed
crabs containing high amounts of chlorinated hydrogen
pesticide residues causing Handigodu syndrome. The
pesticides used in agriculture practic-^^ were taken
up by the crabs. The syndrome is a type of acnendroplastic
dwarfism.

17. 17
V.6.8. Vinyl chloride : After the discovery that vinyl chloride
caused a rare type of liver cancer in occupationally ex-
posed persons, concern has Increased at the possibility
of general community measures. The appearance of 2 cases
of liver angiosarcoma in persons living near vinyl
chloride emission sources, suggested that such emissions may
indeed pose a community threat. Chronic exposure in
workers causes blanching and tingling of hands, tenderness
of finger tips as signs of Raynaud's phenomenon and
acro-osteolysis wherein X-Ray of the distal phalynges of
the hand show lytic lesions.
V.6.9 Hydrocarbons^ Hydrocarbons enter the atmosphere from
natural as well as technologic emissions and transportation
accounts for 52 percent of emissions in the latter category.
Photochemical reactions in the atmoshpere can produce
other hydrocarbons such as aldehydes and kotones and
accetones. Hydrocarbons may enter the atmospheric reaction
process leading to formation of ozone and other photo-
chemical oxidants. In their own right, hydrocarbons may
induce adverse health effects.
V.6.10 Isocyanates : They cause irritation of the eyes, respiratory
tract, and skin„ $sthmatlc reaction, wheezing, breathlessness
cough follow leading to bronchitis and pulmonary Oedema.
V.6.11 Pollens : Allergy to pollens in the ambient air has been
one of the important caus.es of respiratory disease.
Recent studies by Dr. Agnihotri have highlighted the
higher prevalence of allergic lung diseases in areas
having higher concentration of pollens in the atmosphere.
VI. Evaluating the overall health risks of air pollution.
Evaluation of health risks Involves 4 component tasks. 1.

18. : 18
Identifying the health effects of air pollution. 2.
Quantifying these effects at various concentrations, 3.
estimating how many people are exposed at these concen-
trations, and calculating the overall health risk
associated with a given degree of air quality.
As much as it has been possible to demonstrate the health
effects of air pollution as a whole, it has not been
possible to quantify the health effects in relation to
specific amounts of individual pollutants. Biologic
response to air pollution can range from irritating
sensory effects and physiologic changes to disease,
disability and death.
VII. Conclusion
Air pollution has come to stay in metropolitan & industrial
towns. Both environmental monitoring-and health monitoring
of the exposed population has to be done regularly, so that
' the pollution could be controlled '"man of today and
tomorrow could live a healthier and happier life.