The below mentioned article provides a short note on Excreta Disposal.
Public Health Importance:
1. Human excreta is an important cause of environmental pollution.
2. Improper excreta disposal causes soil pollution, water pollution, contamination of foods and propagation of flies. The resulting diseases are typhoid and paratyphoid fever, dysenteries, diarrheas, cholera, hookworm disease, viral hepatitis and similar other intestinal infections.
3. Proper disposal of human excreta is a fundamental environmental health service.
Carrying of Disease from Excreta:
The fecal-borne diseases are transmitted to a new host through various channels such as water, fingers, flies, soil and food.
Methods of Excreta Disposal:
Some methods are applicable to unsewered areas and some to sewered areas.
1. Unsewered Areas:
(i) Service type:
Night soil is collected from pail by human agency and later disposed of by burying or composting.
(ii) Non-service type:
Bore hole latrine, Dug-well latrine, water-seal type of latrine, septic tank, aqua privy.
(iii) Latrines for camps:
Shallow trench latrine, deep trench latrine, pit latrine, bore hole latrine.
2. Sewered Areas:
Sewage treatment:
(a) Primary treatment:
Screening, removal of grit, plain sedimentation.
(b) Secondary treatment:
Trickling filters, activated sludge process.
(c) Other methods:
Sea outfall, river outfall, sewage farming, oxidation ponds.
1. Service Type:
(a) The collection and removal of night soil from bucket by human agency is called the service type, and the latrines are called service latrines.
(b) Service latrines are a source of insanitation. They have the drawbacks and faults which tend to carry the disease cycle of fecal-borne diseases in the community.
(c) The night soil is exposed to flies and there is always the possibility of water and soil pollution.
(d) The emptying occupation of buckets is not always satisfactory.
(e) It is also difficult to recruit adequate staff for the collection of night soil. If the sweepers go on strike, the entire machinery collapses with bad results to public health.
(f) The human labour for the collection of night soil is un-favourable with human dignity.
(g) The environmental hygiene committee has, therefore, recommended that the service latrine should be replaced by sanitary latrine.
2. Sanitary Latrines:
A Sanitary latrine fulfils the following criteria:
(a) Excreta should not contaminate the ground or surface water.
(b) Excreta should not pollute the soil.
(c) Excreta should not be available to flies, rodents, animals.
(d) Excreta should not create a nuisance due to odour.