Environment and health in developing countries
Priority risks and future trends
From longstanding to emerging hazards, environmental factors are a root cause of a significant burden of death, disease and disability – particularly in developing countries. The resulting impacts are estimated to cause about 25% of death and disease globally, reaching nearly 35% in regions such as sub-Saharan Africa (1). This includes environmental hazards in the work, home and broader community/living environment.
A significant proportion of that overall environmental disease burden can be attributed to relatively few key areas of risk. These include: poor water quality, availability, and sanitation; vector-borne diseases; poor ambient and indoor air quality; toxic substances; and global environmental change. In many cases, simple preventive measures exist to reduce the burden of disease from such risks, although systematic incorporation of such measures into policy has been more of a challenge. Below are estimates of deaths globally from the most significant environmentally-related causes or conditions, and from certain diseases with a strong environmental component:
- Unsafe water, and poor sanitation and hygiene kill an estimated 1.7 million people annually, particularly as a result of diarrhoeal disease (2).
- Indoor smoke – primarily from the use of solid fuels in domestic cooking and heating – kills an estimated 1.6 million people annually due to respiratory diseases (2).
- Malaria kills over 1.2 million people annually, mostly African children under the age of five (3). Poorly designed irrigation and water systems, inadequate housing, poor waste disposal and water storage, deforestation and loss of biodiversity, all may be contributing factors to the most common vector-borne diseases, including malaria, dengue and leishmaniasis.
- Urban air pollution generated by vehicles, industries, and energy production kills approximately 800 000 people annually (2).
- Road traffic injuries are responsible for 1.2 million deaths annually; low- and middle-income countries bear 90% of the death and injury toll. Degradation of the built urban and rural environment, particularly for pedestrians and cyclists, has been cited as a key risk factor (4)(5).
- Lead exposure kills more than 230 000 people per year and causes cognitive effects in one third of all children globally; more than 97% of those affected live in the developing world (6).
- Climate change impacts – including more extreme weather events, changed patterns of disease and effects on agricultural production – are estimated to cause over 150 000 deaths annually (2)(7).
- Unintentional poisonings kill 355 000 people globally each year (3). In developing countries – where two-thirds of these deaths occur – such poisonings are associated strongly with excessive exposure to, and inappropriate use of, toxic chemicals and pesticides present in occupational and/or domestic environments (8, 9).