Water quality and health

There is still serious impact of inadequate and unsafe water supply on human health in many countries, and not only in developing ones. Waterborne diseases, such as diarrhoea, are responsible for more than 3 million deaths per year. Vector-borne diseases, such as malaria and schistosomiasis, are still rampant in the tropics causing severe human suffering and economic losses. Chemical hazards related to water are not only due to the presence of toxic substances, such as pesticides or heavy metals, but also due to excessive or deficient amounts of natural substances such as fluoride or iodine. Chemical risks have to be balanced with biological risks, and disinfection practices enforced without compromises. There is a long way to go, however, to fill the gaps in service coverage for water supply and sanitation, particularly in the rural areas and in the impoverished periurban areas. Various international programmes are in place or being initiated to this end.