Air Pollution and Human Health: From Local to Global Issues

摘要

Air pollution from fossil fuel combustion has been known to affect human health for centuries. More detailed insights developed in the 20th century, as a result of studies prompted by severe air pollution episodes such as those in the Meuse Valley, Belgium in 1930, and London, UK in 1952. In the Meuse Valley, stagnant weather conditions prevented local, industry-generated pollutants from dispersing during several days in December 1930 (1). Several dozens of people died suddenly, and the episode attracted worldwide attention. In December 1952, stagnant weather conditions prevented local pollution dominated by coal smoke from dispersing in London, UK. It was initially estimated that some 4,000 people died as a result, but later estimates, taking into account delayed effects in the following months, put the figure at perhaps as high as 10,000 (2). In the second part of the 20th century, pollution abatement measures were taken in many developed countries as a result of these dramatic events, and urban pollution levels declined. Emphasis shifted to secondary pollutants formed in the atmosphere as a result of chemical reactions, notably ozone and fine particles. Many studies have been published on the health effects of these pollutants, showing that day-to-day variations in their levels are associated with adverse health outcomes including mortality even at very low levels of exposure. For ozone, the associations with mortality are a relatively recent finding that was confirmed by three independent reviews (3-5). Associations between particulate matter and health have been reported from many areas (6). This review discussed six dimensions of associations between ambient PM and health: (1) short term exposure and mortality; (2) long term exposure and mortality; (3) time scales of exposure; (4) the shape of the concentration-response function; (5) cardiovascular disease; and (6) biological plausibility.