WHO human health risk assessment toolkit

Overview

The production and use of chemicals are increasing worldwide. For example, the global output of chemicals increased approximately 10-fold between 1970 and 2010. In this respect, an important trend is being observed: chemical production continues to grow faster in countries that are not members of the Organisation for Economic Co-operation and Development (OECD) than in OECD countries, and this trend is expected to continue and even accelerate. OECD estimates that non-OECD countries, which were responsible for about 17% of the global production of chemicals in 1970, will be producing 31% of an even larger world production in 2020.

WHO estimates that more than 25% of the global burden of disease is linked to environmental factors, including exposures to toxic chemicals. Lead exposure, for example, accounts for 3% of the cerebrovascular disease burden and 2% of the ischaemic heart disease burden worldwide. Some 9% of the global burden of lung cancer is attributed to occupational exposure to toxic substances, and 5% to outdoor air pollution. Lung cancer and mesothelioma are caused by exposure to asbestos, which remains in use in some countries. Unintentional poisonings kill an estimated 355 000 people each year, two thirds of them in developing countries, where such poisonings are strongly associated with excessive exposure to, and inappropriate use of, toxic chemicals, including pesticides.