Human health impact of chemical contaminants in drinking water – usefulness of the DALY concept
Health loss due to exposure to (potentially) harmful chemical contaminants in drinking water can be
predicted by a health impact assessment. A health impact assessment is defined by the WHO as a
combination of procedures, methods and tools by which a policy, programme or project may be judged
as to its potential effects on the health of a population, and the distribution of those effects within the
population. A health impact assessment can be used to determine which environmental factor or
compound in drinking water has the greatest impact on public health. The exposure to various hazards
that can be present in water may result in very different health outcomes. Some outcomes are mild (e.g.
diarrhoea), while others can be severe (e.g. cholera or cancer); some are acute (e.g. diarrhoea), while
others are delayed (infectious hepatitis or cancer).