Hydropower development had been neglected in many countries during the past few decades, but the situation dramatically changed during the 1970s owing to the constantly increasing costs of electricity generation by fossil-fuel and nuclear power plants. Currently, hydroelectric generation accounts for approximately 23% of total global electricity supply. Much of the hydropower potential in developing countries of Africa, Asia and Latin America still remains to be exploited. Like any other source of energy, hydropower development has several health impacts. Conceptually, health implications of hydropower development can be divided into two broad categories: short-term and long-term problems. Short-term health impacts occur during the planning, construction and immediate post-construction phases, whereas long-term impacts stem from the presence of large man-made lakes, development of extensive canal systems, alteration of the ecosystem of the area, and changing socio-economic conditions. Longer-term impacts are further classified into two categories: introduction of new diseases and/or intensification of existing ones due to the improvements of the habitats of disease-carrying vectors, and health problems arising from resettlement of the people whose homes and land-holdings are inundated by the reservoirs. All these impacts are discussed in detail. Health impacts of hydropower developments have not yet been studied extensively. It is often implicitly assumed that health impacts of major dams are minor compared with other social and environmental impacts. Future studies could possibly reverse this assumption.
By Asit K. Biswas, Invited Paper, International Atomic Energy Agency, Vienna, 1982.