Sitting up close to a camp fire—or a forest fire—you get a sense that breathing in smoke isn't very good for you. The same goes for automobile exhaust, emissions from burning coal, and other air pollutants. Now, new research confirms that fine particulate matter, as it's called, increases the risk of premature death in the United States, highlighting the ongoing need to reduce human-made contributions to air pollution.
It's well known that exposure to airborne particles smaller than 2.5 micrometer—known as fine particulate matter, or PM2.5—has adverse health effects. PM2.5 levels have dropped considerably since the Clean Air Act was passed in 1970, leading some conservatives to suggest there are few, if any, health benefits to be had from further reductions (i.e. no need for tighter regulations).
Even with tightening air quality requirements, there's still room for improvement.
George Thurston, a professor of environmental medicine at the New York University School of Medicine, argues otherwise. "The benefits of cleaning the air are always there," even if airborne PM2.5 levels decrease well below current regulatory requirements, he says.
Thurston and colleagues from NYU, the University of California–Berkeley, Washington University, and the National Cancer Institute reached that conclusion after analyzing data originally collected as part of the National Institutes of Health-AARP Diet and Health Study, which surveyed more than half a millions Americans ages 50 to 71 starting in 1996, followed by a second round of interviews with the same participants beginning in 2005. In addition to a wide range of demographic and health data, the NIH-AARP study included information on where survey respondents lived, allowing Thurston's team to link it with Environmental Protection Agency air quality data at the local level. That means the team was not only able to update previous research on the link between fine particulate matter and health, they could also do it in much greater detail.
The results, published in Environmental Health Perspectives, indicate that, even with tightening air quality requirements, there's still room for improvement, Thurston says. For every 10 microgram per cubic meter increase in PM2.5, there's about a three-percent increase in the overall mortality rate, he and his co-authors conclude, and a 10-percent increase in the mortality rate associated with cardiovascular disease.
Most important, Thurston says, is that those effects are still there even at very low concentrations—down to two or three micrograms per cubic meter, well below the EPA's current 12 microgram per cubic meter standard for regulatory intervention. This means tighter regulations should help Americans live longer, healthier lives.
And if that's not enough, Thurston points out the work of economist Jason West, who recently argued that reducing air pollution in the form of carbon emissions translates into more productive workers—to the tune of $50 million or more per metric ton of carbon emissions.
Quick Studies is an award-winning series that sheds light on new research and discoveries that change the way we look at the world.