Those affected the most are the impoverished populations living in rural and peri-urban areas. The number of urban poor is growing rapidly and it is estimated that in the year 2000 at least 1000 million people in urban areas will be counted among the poor. As many as 1000 million people, mostly women and children in developing countries, are exposed to high levels of indoor air pollution. The occurrence of the major vector-borne diseases is closely related to naturally existing environmental conditions. In addition, the incidence, severity and distribution of vector-borne diseases are affected substantially by human activities such as water and agricultural developments and by urbanization.
Malaria is a major health problem related to environmental conditions.
Over 500 million people are affected by malaria in over 90 countries. The problem is increasing at least in part due to land degradation, deforestation, the expansion of agriculture and mining into new areas, and urbanization. Other major vector-borne diseases, each one affecting more than 10 million people and being particularly influenced by environmental conditions, such as water, sanitation and housing, include Lymphatic filariasis, Schistosomiasis, Leishmaniasis and Chagas disease. The lack of detailed quantitative information on the production and disposal of such waste, and the lack of information on the health risks severely hamper the efforts to control this problem. Thousands of new chemicals are developed each year and the assessment of their risks to health and the environment cannot keep pace.