This document discusses environmental health and sanitation, focusing on sewage disposal, refuse disposal, and pest/vector control. It describes various methods of sewage and refuse disposal including pit latrines, flush toilets, septic tanks, and proper refuse collection and disposal. Regarding pest/vector control, it defines vectors, provides examples of disease-carrying vectors like mosquitoes and rodents, and outlines steps for vector control including identifying breeding sites and applying appropriate treatments. The role of sanitation in preventing disease transmission is emphasized throughout.

1. ENVIROMENTAL HEALTH AND
SANITATION (PART 1)
Presented
By
G. C. Sibande MPH, RNM

2. Objectives
• Describe environment
• Describe components of the environment that
influence health
• Describe the following components of
environmental health:
Sewage disposal
Refuse disposal
Pest/ vector and pest/ vector control

3. Introduction
• This unit focuses on environmental health issues
that influence the health of individuals, families
and communities.
• Environment is the collective term used to
describe all the living and non-living things that
make up our surroundings.
• These include the biological, technological,
physical, cultural, social, economic and political
aspects.

4. Components of the environment
• The physical environment consists of air, water,
soil, climate and other physical conditions.
• Biological environment includes living things
like the plants, animals and microorganisms.
These also influence the health of the people.
• The social, technological and political
environments are man made e.g. The family,
village, culture, beliefs, industries, politics and
the government.

5. Description of the environmental
health
• Environmental health encompasses all elements
of the environment that influence people’s health
and well being.
• It is concerned with assessing, controlling and
improving the impact people make on their
environment and the impact of the environment
on people.
• The health, and even the survival of man
depends on his ability to adjust or adapt to the
environment.

6. Cont...
• Activities aimed at improving the quality of
the environment and reducing the amount of
disease is known as environmental sanitation
• It is one of the most important aspects of
primary prevention.
• Therefore it is the responsibility of all health
workers to help improve the environment.

7. SEWAGE DISPOSAL

8. Objectives
• Define sewage and sewage disposal
• Explain how excreta is disposed
Describe different types of latrines
Describe a water carriage system
Explain how the sewage system works

9. Sewage
• Sewage is waste material comprised of faecal
matter, urine, vomits, sullage from personal
washing, laundry, food preparation, the
cleaning of kitchen utensils, industrial and
agricultural wastes that is carried away in
water from homes and buildings in a system of
pipes

10. Sewage disposal
• Proper sewage disposal directly involves
disposal of human excreta and watery wastes
through latrines and water carriage systems
• Hygienic disposal of excreta forms the basis of
good hygiene in any household
• Prevents bad odour and presence of flies
• Prevents the spread of diseases directly or
indirectly through the 4 F connections -
diseases such as Typhoid, cholera, Hepatitis A,
dysentery e.t.c.

11. The 4 F connections
FLIES
FOOD
FAECES
FINGERS

12. Latrines
• A common method of excreta disposal in rural
areas is the pit latrine.
• A pit latrine consists of a hole in the ground, a
squatting plate (on which to squat) when
defecating or urinating.

13. Types of latrines
Pit latrine
• Traditional pit latrine
• San- plat (Sanitation Platform) – squatting slab
structurally safe, footrest - good for easy positioning to
reduce fouling, hole too small for child to fall in, cement
floor – easy to clean, some fly control with tight fitting
lid
• VIP (ventilated improved pit) It has a black vent pipe
fitted to the pit and a fly screen at the top outlet of the
pipe – eliminates odour and flies through air circulation
• Composting latrine
Bucket latrine

14. Pit latrine
Construction considerations:
• Pit latrine should be on dry ground where water
drains away, and with a surrounding storm-water
drain.
• The soil must be porous to allow the liquid to
drain away
• A pit latrine should be situated 15 meters away
from the water source if on the same level or
below the source, or more than 30 meters if the
latrine is above the water source.

15. Pit latrine contd
• Must be fly proof - pit must be 3.5 - 5 metres
deep. (10 feet deep) covered with concrete
platform or skilfully constructed floor with
local materials
• Have a reasonable cover over the hole
• It should have a pipe which goes deep into the
hole and out over the roof to remove odour

16. Pit latrine contd
Advantages
• Best for rural areas with no piped water
• It has an initial financial outlay but low
running cost
• Has long life span -bacteria act on the faeces
and convert the solid into liquid.
• It can be accessible to the local community
• It is suitable for mass usage

17. Pit latrine contd
• Faeces need no further handling after disposal
Care:
• The cement platform must be cleaned daily
• If the platform is constructed with mud, smear
at least one a week and sweep daily
• The hole should be covered with a fitting
cover to prevent odour and flies.

18. Bucket latrine
• A bucket receives the excreta
• Commonly used in town with no adequate
water carriage system
• Expensive to run
• Has to be emptied every night
• Difficult to find workers for this type of job

19. Flush toilet/ water closet
• The most hygienic way of dealing with foul liquid
waste and human excreta when properly used.
• Flush toilets need a permanent, continuous and
adequate piped-water supply to work efficiently
• Any failure of the water supply makes them
unhygienic to use.
• Drains and sewers collect the sewage
• Their construction is more complicated and
expensive, and can only be done by trained
workers.

20. Water carriage system
There are two types of water carriage systems:
• Small scale systems- Water closet (flush
lavatory) connected to a septic tank- this is
ideal for a house, health centre or small school
• Larger systems- Water closet (flush lavatory)
with direct sewer connection where sewage
ponds or lagoons are used and are sited some
distance away from buildings in the open air,
also biological action takes place. Mostly used
in urban centres.

21. Water closet
• Consists of:
• Porcelain pan with a seat
• 5 litres flushing cistern which empties the pan
of water and excreta
• S – shaped bend – acts as a trap, with a water
seal to prevent bad odours coming from the
waste pipe
• Connecting pipe, soil pipe and inspection
chamber
• House drain leading to a sewer or septic tank

22. Septic tank
• Ideal for isolated buildings and institutions where
there is no sewer
• Sewage is retained for days
• Heavy sediments settle as sludge
• Effluent escapes through the outlet pipe and soak
away pit.
• Bacteria and fungus make the sewage sludge and
effluent harmless
• The tank has to be emptied of sludge regularly
• The tank is sunk below the ground and should always
covered.

23. Septic tank contd
Advantages:
• minimal running costs
• Waste matter not handled
• Waste matter is inaccessible
• No disease risk
• No odour if properly constructed

24. Septic tank contd
Disadvantages
• Initial outlay expensive
• May smell if poorly constructed
• Emptying becomes expensive

25. Sewage works disposal
• Sewage may be pumped out to sea in coastal
areas but is not advisable.
Alternatively, biological method is used as
follows:
• Sewage is passed through a grid to remove
paper.
• Sand and grit are removed next then
sedimentation occurs.
• The sewage moves to the settling tanks where
solid sludge forms.

26. Sewage works disposal contd
• The effluent (top fluid) becomes harmless by
exposure to the air and bacteria.
• The harmless fluid is drained into rivers or
lakes.
• The sludge is removed, treated dried and sold
as manure

27. Role of community health nurse
• Individual and population risk assessment
• Risk communication
• Community involvement
• Epidemiologic investigation
• Advocate for policy development

28. REFUSE AND REFUSE DISPOSAL

29. Objectives
• Define refuse
• Describe types of solid waste
• Describe sources of solid waste
• Explain importance of proper waste disposal
• Describe disposal methods
• Discuss health care waste management

30. Definition
• Refuse or solid waste is anything that needs to
be disposed off or thrown away.
• Refuse or solid waste is considered as
something which is no longer wanted in a
given place and time.

31. Types of solid waste
• General waste - municipal waste or non-
hazardous waste
• Hazardous waste – one that poses substantial
potential hazard to human health or living
organisms

32. Sources of solid waste
• Residential/domestic - left over foods, waste
paper, plastic bags
• Commercial
• Institutional
• Industrial
• Agricultural
• Construction and demolition
• Municipal services e.g. street sweeping,
street- wrecks of cars, plastics and papers

33. Importance of proper waste disposal
• Rotting, decaying organic matter attracts insects
and vermin and cause fly breeding places.
• Collection of stagnant water in cans, bottles and
tyres provide breeding places for mosquitoes.
• Decaying refuse has a bad odour – air pollution
• Children may injure themselves on broken
bottles
• Can cause fires

34. Importance of proper waste disposal
contd
• Ground and surface water supplies may be
polluted by accumulated refuse especially in
wet season.
• Industrial waste contain harmful chemicals
which make local inhabitants at risk and can
also affect agriculture and fisheries
• Hospital refuse contain harmful bacteria and
viruses that can spread infection

35. Disposal methods
This depends on the types of refuse and can
be one of the following ways:
• Crude damping
• Burning
• Burying
• Incineration
• Controlled tipping

36. Crude dumping
• Open dumping or uncontrolled dumping. This
is a very unsatisfactory method of dumping
because of fly, mosquito and rodent breeding,
water pollution, air pollution from smells.

37. Proper disposal methods
Dry refuse disposal in urban:
• Should be put in a dust bins with heavy well
fitting lids to discourage dogs, rats and flies
• The dust bin should stand on a firm concrete base
be kept clean, scrubbed out regularly and dried in
the sun
Dry refuse disposal in rural areas:
• The rubbish should be burned or buried in a pit
• The ashes can be used as manure
• Vegetable and fruit peelings can be used as
compost

38. Proper disposal methods contd
• Animal carcasses should be removed and
buried to prevent flies. Veterinary officers
should be informed.
• Dog excreta should be removed around the
home and buried to avoid flies and prevent
children from playing on it.

39. Incineration/burning
• Burning in a simple mud brick incinerator.
• A bin incinerator made out of a drum with fire
bars across it and air holes underneath is an
effective and affordable way of disposal.
• Ideal incinerators may be used

40. Composting
• Wet and dry refuse is heaped onto alternate
layers onto a plot about 1.5 metres then
covered with grass or earth.
• Fermentation decomposes the refuse, which
should be turned after 30 days and again at 60
days.
• After 90 days, the refuse is ripe and may be
put on the land as fertiliser.

41. Controlled tipping (controlled
burial)
• Solid waste is disposed off into a dug pit and
regularly covered with soil in form of alternate
layers of waste and soil to avoid attracting
disease vectors such as flies and rodents

42. Health care waste management
• Health care waste – waste generated in health
care centres
• 75-95% of the health care waste is general
waste (similar to domestic waste)
• 10-25% is hazardous waste (infectious, toxic
e.tc)

43. Health care waste
Note:
Health care waste should be handled with
great care and should be disposed in separate
bins for:
non-contaminated waste – which include
papers from the nursing station, plastic juice
bottles
contaminated waste - that is infectious
sharps - which include contaminated needles
and scalpel blades.

44. Health care waste contd
Health care activities(human) that generate
waste include:
• Diagnosis
• Treatment
• Prevention of disease
• Alleviation of disablement
• Associated research

45. Health care waste contd
Major sources of health care waste:
• Hospitals
• Clinics
• Laboratories
• Research centres
• Blood banks
• Nursing homes
• Mortuaries

46. Health care waste contd
Hazardous properties of health care waste:
• Infectious
• Sharps
• Pharmaceutical
• Genotoxic
• Chemical
• Radioactive

47. Health care waste contd
Hazardous properties of chemical waste:
• Toxic
• Corrosive
• Flammable
• Reactive
• Explosive
• Genotoxic

48. Health care waste contd
Who is at risk?
• Doctors and nurses
• Patients
• Hospital support staff
• Waste collection and disposal staff

49. Health care waste contd
Public health risks (potential health effects):
• AIDS
• Hepatitis B and C
• Respiratory infections
• Skin infections
• Effects of radioactive substances – cancers,
birth defects for unborn babies

50. Health care waste contd
Good waste management depends on:
• A dedicated waste management team
• Good administration
• Careful planning
• Available legislation
• Adequate financing
• Full participation by trained staff

51. Health care waste contd
Waste management team:
• Hospital manager
• Waste management officer
• Heads of department
• Infection control officer
• Senior Nursing sister
• Hospital engineer
• Finance officer
• Chief pharmacist
• Radiation officer

52. Health care waste management
Minimization, reuse, recycling and
segregation of health care waste:
• Waste minimization - reducing the amount
of waste produced in a society at the point of
production e.g. Plastic water bottles
• Reuse: products are used again for the same
purpose. Only materials designed to be re-
used e.g. Endoscopy tubes i.e. Catheters and
plastic syringes should not be reused

53. Health care waste management
• Recycling – converting waste material into
new. packaging material can be recycled e.g.
Cardboard boxes, glass, metal container,
plastic wrappings .
• Waste segregation – dividing waste into dry
and wet

54. Health care waste contd
• Recommended colour coding of waste plastic
bags:
• Yellow/ Red for infectious waste
• Brown for chemicals and pharmaceutical
waste
• Black for general use

55. Health care waste management
Waste collection:
• Establish a routine programme for collection
e.g. collect ward waste daily
• Sharps containers should be sealed when ¾
full and replaced by another one.

56. Health care waste management
Waste storage facilities:
• Impermeable hard standing
• Easy to clean
• Readily accessible to staff
• Secure and lockable
• Good lighting and ventilation
• Proofed against rodents, insects and birds

57. Health care waste contd
Waste storage periods:
48 hours in cool season
24 hour in hot season
Waste labelling:
Date of production
Place
Waste quantity
Waste quality
Waste destination

58. Health care waste contd
Final disposal:
Municipal landfill
Burying inside premises
Incineration:
• High temperature oxidation process
• Reduces to ashes - reducing waste volume & wt
• Not all waste can be incinerated e.g. pressurised
gas containers, reactive chemical waste

59. PEST / VECTOR CONTROL

60. Outline
• What is a vector?
• Examples of vectors and their diseases
• Vector control steps
• General control measures
• Mosquito control
• Fly control activities
• Rodent control activities

61. What is a vector?
• A vector is an organism/agent (Insect/
animal/vermin) that carry disease causing
organisms from one animal/person or act as
the intermediate host
• The vectors do not suffer from the diseases

62. Pests/vectors
• Vectors/pests spread some of the common
diseases.
• It is useful to consider what can be done to
control pests.
• The control of insect pests ad vermin should
take into consideration the life cycle and the
general conditions favourable to their growth.
• This enables health personnel to identify
possible methods for intervention and control.

63. Examples of vectors and their
diseases
• Mosquitos: Malaria, yellow fever, dengue
fever, elephantiasis
• Black flies: Oncorcerciasis (River blindness)
• Snails: Schistosomiasis/ Bilhazia
• Rodents( rats): plague
• Fleas: Plague

64. Other common pests
• House flies
• Bed bugs
• Ticks
• Tsetse flies
• Mites
• Human lice

65. Vector control steps
• Complaint investigation
• Identification of routine breeding sites
• Surveillance of new or potential breeding sites
• Application of appropriate treatment

66. Control Measures
• Biological: Use of predators
• Chemical: e.g. Spraying, baiting (poisoning)
use of repellents
• Physical: trapping
• Use of personal protective equipment
• Environmental management
– Destruction of breeding sites
– Proper environmental hygiene
– Proper management of water schemes
– Proper disposal of wastes

67. Mosquito control
• Draining of water troughs
• Repairing of water leaks
• Vegetation removal – loan mowing
• Proper disposal of empty tins
• Removal of floating debris in ponds

68. Fly control activities
• Trash can rinsing
• Keeping lids on trash cans
• Bag and tie debris
• Burning of refuse
• Daily picking of pet and poultry droppings
• Reporting about all fly breeding sites

69. Rodent control activities
• Eliminate openings for rodents in the home
• Trap and bait placing along runaways
• Best rodent control measures include
- Good sanitation
- Rodent proof construction
- Cats

70. General methods to control pests/
vectors
• Disposing of all refuse, any decaying matter,
faeces properly- that is burying, burning or
composting for fertiliser.
• Keeping all surroundings clean all the time
• Keeping all food vessels and utensils clean
• Draining or filling up water holes and ditches.
• Clearing bush and grass along the banks of rivers
and ponds.
• Spraying insecticides in the environment.

71. Thank you!
ANY QUESTIONS??

72. Activity
• Describe the types of environment and their
influence on health
• Describe environmental degradation and its
influence on health
• Identify the types of chemicals that may
predispose to cancer