Gaseous household wastes arise mainly from heating and cooking.
They contribute substantially to both outdoor and indoor air pollution. Liquid wastes are the by-products of domestic activities. In most areas of developing countries, feces are recycled for use in agriculture or deposited on land without prior destruction of pathogens. Not surprisingly, infectious disease such as diarrhoeal diseases, schistosomiasis and hepatitis are endemic, and some times epidemic, in such areas.