Air Pollution and Health

Abstract

Evidence showing that current concentrations of air pollutants have effects on health continues to accumulate. Both long-term and short-term exposure to particulate matter causes an increase in deaths from cardio-pulmonary disease and admissions to hospital. Long-term exposure to fine particles (measured as PM2.5) has also been shown to be associated with an increase risk of death from lung cancer. Methods for estimating the impact of air pollutants on health have been developed, these include: estimates of the burden of disease imposed by air pollution and the impacts of policies designed to reduce levels of air pollutants. Such methods allow the application of cost–benefit analyses to specific policy initiatives. Exposure to current levels of fine particles is associated with the equivalent of nearly 29 000 deaths each year in the UK and the loss of 340 000 years of life expectancy. The toxicological mechanisms underlying these effects remain imperfectly understood though it is clear that the majority of the burden on public health arises as a result of effects on the cardiovascular system. It is striking that the major effects of cigarette smoking: an increase in risk of death from cardiovascular disease and from lung cancer and a reduction in birth weight are mirrored by the effects of long-term exposure to the ambient aerosol. Progress regarding the effects of gaseous air pollutants has been limited, though recent work suggests that the effects of ozone are not characterised by a threshold and that nitrogen dioxide, even at low concentrations, may have an effect which is independent of the effects of particulate matter with which nitrogen dioxide is closely associated in urban areas.