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Diane Bailey’s Blog

Study finds we're living longer thanks to cleaner skies

Diane Bailey

Posted December 5, 2012

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Two new studies have been released this week underscoring the critical role that particulate pollution plays in our nation’s health status from quality of life to longevity.  The first is a correlation of changes in fine particulate (“PM2.5”) levels related to life expectancy rates.  The Harvard School of Public Health study took data on air pollution and life expectancy rates in more than 500 counties throughout the U.S. between 2000 and 2007.  They found strong evidence of an association between reductions in PM2.5 and improvements in life expectancy, especially in densely populated areas. 

While life expectancy has grown due to many factors such as improved prevention and control of diseases, this study showed that improved air quality was responsible for almost 20 percent of increases in longevity in urban areas.  PM2.5 has long been linked to premature mortality.  What this study shows is that control programs to reduce PM pollution demonstrate real results in greater longevity of the population.

On the other hand, the obesity epidemic may be putting more Americans at greater health risk due to air pollution.  A paper released today by the University of Michigan, School of Public Health explores the heightened vulnerability of obese adults to air pollution and why EPA’s update to the National Ambient Air Quality Standards (NAAQS) for PM2.5 should account for this.  The paper notes that EPA considers pre-existing cardiac and respiratory conditions in people as comprising sensitive populations that are more susceptible to PM pollution.  However, obese adults, who make up roughly one third of the U.S. population are not considered in those sensitive groups.

This is a problem, not only because obese individuals have a greater disposition to many chronic illnesses, but in particular that it is more difficult for them to breathe.  Obesity increases oxygen consumption putting greater stress on the respiratory system while at the same time hampering the full functioning of the respiratory system (think of sleeping with extra weight on your chest).

Unfortunately, it is likely too late for these important new findings to influence the final federal PM NAAQS rule that are slated to be complete in the next few weeks. However, in these final weeks of deliberations over the new standards, it bears repeating that scientists at EPA recommend that the current annual PM2.5 standard level of 15 μg/m3 (micrograms per cubic meter) be lowered to a level within the range of 11 to 13 μg/m3. At the lower end of the range - 11 μg/m3 - we estimate that up to 27,300 lives per year would be saved. It also bears further consideration that not only will a lower standard improve longevity it will lessen the burden of illness on the 34 percent of the American population that is obese. 

A truly health protective new PM standard would make a fine gift to the American people as we approach a new year.

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