The links between them and poverty are particularly vivid in the devastating toll that environmental degradation takes on human health, the dependence of the poor on natural resources, and their vulnerability to natural disasters and climate change. Poor people are well aware of these threats, as interviews with the poor in over 70 developing countries have shown. They suffer most from the health effects of environmental factors such as dirty water, polluted air, poor sanitation and hazardous waste. During the dry season, from August to January when the springs become dry, we have to walk 2 kilometres to Kishimbo to get water. Oldadai, Arusha, United Republic of Tanzania Premature death and illness caused by environmental health risks account for one-fifth of all disease in the developing world, more than the 15 per cent due to malnutrition, and greater than all other preventable risk factors and groups of disease.
Diseases associated with environmental factors are highly concentrated among the poor.
Around 60 per cent of all malaria deaths, and half of all fatalities from diarrhoea, for example, occur among the poorest 20 per cent of the world's people. In sub-Saharan Africa, improved water and sanitation, cleaner household energy, better housing, vector control, and pollution management can reduce the total burden of disease by an estimated 23 to 29 per cent. Poor people, particularly those living in rural areas, also depend on natural resources such as water, soil and fisheries for subsistence and income. Yet environmental factors are seriously undermining the ability of the poor to wrest a living from natural resources. The livelihoods of more than a billion rural people are at risk as a result of desertification and dryland degradation.