Global environmental change and health: impacts, inequalities, and the health sector.

Human actions are changing many of the world's natural environmental systems, including the climate system. These systems are intrinsic to life processes and fundamental to human health, and their disruption and depletion make it more difficult to tackle health inequalities. Indeed, we will not achieve the UN millennium development health goals if environmental destruction continues. Health professionals have a vital contributory role in preventing and reducing the health effects of global environmental change. Problems of focus In 2000 the United Nations set out eight development goals to improve the lives of the world's disadvantaged populations. The goals seek reductions in poverty, illiteracy , sex inequality, malnutrition, child deaths, maternal mortality, and major infections as well creation of environmental stability and a global partnership for development. One problem of this itemisation of goals is that it separates environmental considerations from health considerations. Poverty cannot be eliminated while environmental degradation exacerbates malnutrition , disease, and injury. Food supplies need continuing soil fertility, climatic stability, freshwater supplies, and ecological support (such as pollination). Infectious diseases cannot be stabilised in circumstances of climatic instability, refugee flows, and impoverishment. The seventh millennium development goal also takes a limited view of environmental sustainability, focusing primarily on traditional localised physical, chemical, and microbial hazards. Those hazards, which are associated with industrialisation, urbanisation, and agriculture in lower income countries, remain important as they impinge most on poor and vulnerable communities. Exposure to indoor air pollution, for example, varies substantially between rich and poor in urban and rural populations. And the World Health Organization estimates that a quarter of the global burden of disease, including over one third of childhood burden, is due to modifiable factors in air, water, soil, and food. This estimated environment related burden is much greater in low income than high income countries overall (25% versus 17% of deathsand widening further to a twofold difference in percentages between the highest and lowest risk countries). Heavy metals and chemical residues contaminate local foods, urban air pollution causes premature deaths, and waterborne enteric pathogens kill two million children annually. These relatively localised environmental health hazards , though, are mostly remediable. Meanwhile, a larger scale, less remediable, and potentially irreversible category of environmental health hazard is emerging. Human pressures on the natural environment, reflecting global population growth and intensified economic activities, are now so great that many of the world's biophysical and ecological systems are being impaired. Examples …