A . Hygiene and Sanitation Prevention and control of disease has to address both intrinsic and extrinsic factors which are linked with various diseases. The box below lists these factors. Table : Intrinsic and Extrinsic factors linked with various diseases Intrinsic/host factors Extrinsic/environmental factors Age, sex, ethnicity, race Physical environment – air, water, soil, housing, climate, geography, heat, light, noise, radiation Biological factors such as heredity, blood groups, enzymes, levels of various substances in blood, e.g., cholesterol Functioning of various organs and systems Biological environment includes the human being, all other living beings such as animals, rodents, insects, plants, viruses, micro organisms Some of these act as disease-producing agents, some as reservoirs of infection, intermediate hosts and vectors of disease Social and economic characteristics, e.g., occupation, marital status, housing Psychosocial factors-emotional well-being, cultural values, customs, habits, beliefs, attitudes, religion, lifestyle, health services, etc.
Lifestyle factors, e.g., nutrition, diet, physical activity, living habits, use of addictive substances such as drugs, alcohol, etc. Among these factors sanitation and hygiene, nutrition and immunisation are key inputs. When we speak of hygiene we are concerned with essentially two aspects: personal and environmental. Health depends to a great extent on the social environment as well as on lifestyle and behaviour, including food intake.
It is also closely related to hygiene. Poor hygiene leads to several infections and infestations such as worm infestations. Environmental hygiene comprises external matter, both organic and inorganic, at the domestic hygiene (home) and community levels. This includes physical factors such as water, air, housing, radiation, etc., as well as biological factors such as plants, bacteria, viruses, insects, rodents and animals.
F igure : P ersonal A spects of H ygiene Personal Hygiene Water supply Housing Disposal of liquid wastes and sewage Vector control, e.g., mosquitoes and malaria Food sanitation Disposal of human excreta Sanitary practices Garbage disposal (solid waste management) Environ- mental hygiene F igure : E nvironmental A spects of H ygiene Environmental health needs attention so as to create and maintain ecological conditions that will promote health and prevent disease. Among these, safe drinking water and