Human excreta is an important cause of environmental pollution and a source of infection. The HEALTH HAZARDS of improper excreta disposal are soil pollution, water pollution, contamination of food, propagation of flies. These in turn cause number of diseases like typhoid and paratyphoid fever, dysenteries, diarrheas, cholera, hookworm disease, ascariasis, viral hepatitis, other intestinal infections and parasitic infestations.
These diseases are a burden on the community in terms of sickness, mortality and a low expectation of life; and hurdle to social and economic progress. Proper disposal of human excreta is a fundamental environmental health service for improved community health.
How disease is carried from Excreta
The human excreta of a sick person or a carrier of disease is the main focus of infection. The channels of transmission are (1) water (2) fingers (3) flies (4) soil (5) food. The events are shown in Fig. 1.
It is important to break the cycle at vulnerable points like segregation of feces, protection of water supplies, protection of foods, personal hygiene, and control of flies.
Of these, the most effective step would be to segregate the feces and arrange for its proper disposal so that the disease agent cannot reach the new host, directly or indirectly. Fig. 2 shows the segregation of the excreta by imposing a barrier called the "sanitation barrier". The barrier can be provided by a 'sanitary latrine', a disposal pit, installation of sewerage system and sewage treatment plants.