Estimating environmental health impacts

In 2016, as much as 24% of all deaths worldwide were attributable to the environment. Factors include air pollution, water and sanitation, increasing heat waves and severe weather events, harmful exposure to chemicals and more. The estimation of the burden of disease from environmental factors relies on information about exposure and exposure–response relationships.

Understanding how much disease and ill health can be attributed to modifiable environmental risks can contribute to identifying opportunities for prevention and should add impetus to global efforts to encourage sound preventive measures through available policies, strategies, interventions, technologies and knowledge.

WHO combines expertise and evidence to estimate the environmental burden of disease, which quantifies the amount of disease caused by environmental risks. For example, WHO produces internationally comparable estimates on population exposure globally, including working with UNICEF on water and sanitation estimates through the Joint Monitoring Programme for Water Supply, Sanitation and Hygiene (JMP), and global databases on air pollution. WHO also coordinates the development of exposure–response relationships, such as the regular updates of systematic analyses of the impacts of drinking-water, sanitation and hygiene on health. This type of information is then combined to estimate the global burden of disease of various environmental risks to health.