Man-made pollution of the environment has become a main concern of the governments of industrialized nations, but environmental hazards are perhaps most pernicious in the rural regions of the tropics. Epidemics and endemic disease are a constant threat to millions of people, most of them helpless to overcome the danger. There has been a great deal of progress in public health and in international cooperation to fight disease, but much remains to be done. In the more advanced rural communities, sanitation is often of a high standard, with programmes covering nearly the complete range of man's environment. Such communities approach well-developed urban settlements in quality of service. However, in those scattered rural communities not yet collected into villages, and those areas where the rural village is underdeveloped, sanitation is usually minimal or non-existent.
In some small villages, although everyone desires to be healthy, there are certain traditional modes of behaviour that stand in the way. For example, animal waste is often collected in close proximity to humans both in the house and on the village streets and pathways. Raw sewage is deposited near the village, and constitutes a safety, as well as a health, menace to children and animals. Rubbish collection is too infrequent and there are no collection bins, with the result that some villagers simply throw their refuse over the side of a road into a public dump, thus perpetuating another threat to public health.
Residents of most rural villages have little access to the benefits of modern health care. Their vitality may be sapped by chronic infestations of common parasites and worms due to inadequate and contaminated water supplies. Overcrowded living accommodation, in buildings with dirt floors and thatched roofs, promotes the harbouring of dangerous insects. Diets lack adequate vegetables and proteins, either because fruit and vegetables are not grown or because they are not used to their full potential. Many villages have no local milk production or cold storage capabilities. Academic achievements of students may be hampered by chronic infections which are often due to low resistance and nutritional deficiencies, and yet villagers do not understand why they are frequently ill and what makes them sick. Despite growing international awareness that preventive medical procedures are urgently needed to upgrade the physical energy levels of the people of developing communities, until these sanitation problems are solved, the basic health of the people in small villages will remain at an unnecessarily low level; and the human energy required when a particular effort is necessary may simply not be available.
Three out of four people in the Third World excluding China have no sanitary facilities. Although the percentages are following, the total number of people without proper sanitation facilities still increases every year.