Drop in air pollution 'boosts life expectancy'

A link has been found between dropping levels of air pollution and life expectancy, it has been reported.

Research published in the journal Epidemiology has detected an association between reductions in fine particulate matter and improved life expectancy in 545 counties in the US between the years 2000 and 2007.

Lead author Andrew Correia, from Harvard School of Public Health, commented that while Americans are exposed to lower levels of air pollution than they were 30 years ago, further reductions would continue to benefit health.

Scientists looked at the effects on health of fine particulate matter (PM2.5). There is plenty of evidence showing links between acute and chronic exposure to this type of air pollution and cardiopulmonary disease and mortality.

After controlling for socioeconomic status, smoking prevalence and demographic characteristics, scientists found that a decrease of ten micrograms per cubic metre in the concentration of PM2.5 during the period 2000 to 2007, was linked to an average increased life expectancy of 0.35 years.

The results also indicated that a drop in air pollution may be more beneficial to women than to men.

This comes after a study by the same authors that found that reduced air pollution was linked to increased life expectancy in 211 urban counties. The new research, however, considered more recent data as well as many more counties, and took into consideration both rural and urban areas.

There was found to be a stronger association between reductions in PM2.5 and life expectancy in urban areas, which researchers believe is due to the fact that the composition of the particles could be different.

Senior author Francesca Dominici, commented: "Since the 1970s, enactment of increasingly stringent air quality controls has led to improvements in ambient air quality in the United States at costs that the U.S. Environmental Protection Agency has estimated as high as $25 billion per year.

"However, the extent to which more recent regulatory actions have benefited public health remains in question. This study provides strong and compelling evidence that continuing to reduce ambient levels of PM2.5 prolongs life."