A new study from Imperial College London and Carnegie Mellon University’s Center for Air, Climate, and Energy Solutions, published in the PLOS medical journal, estimates that more than 30,000 US deaths, in a single year, can be attributed to air pollution related causes, as a direct result from airborne particulate matter.

Airborne particulates, like PM2.5, often pose the highest risk to human health - due to the pollutants’ prevalence and microscopic size, which allows the particulates to enter the bloodstream and cause far-reaching cell damage.

While the United States has observed significant improvements to air quality over the past several decades, the study makes a case for even stricter air quality regulations, in order to save tens of thousands of lives. The current U.S. EPA guidelines for “good” air quality is an annual PM2.5 average of 12µg/m³ - the WHO guideline is closely aligned with this, at an annual PM2.5 average of 10µg/m³. The new findings reveal that more stringent standards could have significant public health benefits.

To make estimates regarding mortality and reduced life expectancy as a result of PM2.5 pollution, researchers analyzed air quality trends between 1999 and 2015, across 750 monitoring stations, in addition to spatial-temporal vital registration and population data from the contiguous United States. Data was then adjusted using a statistical model for other determinants for mortality.

Using this method, the study found that PM2.5 air pollution exceeding the lowest observed concentration of 2.8 μg/m3, was responsible for nearly 30,000 US deaths. Approximately 15,612 of which were female (95% credible interval 13,248–17,945) and 14,757 of which were male (12,617–16,919). It further concluded that these deaths lowered national life expectancy by an estimated 0.15 years for women and 0.13 years for men.

Los Angeles was the city with the highest life expectancy loss due to particle air pollution. While lower income counties nationwide observed statistically more PM2.5 related deaths than higher income counties.

While reductions in particulate matter pollution over the last several decades have undoubtedly resulted in significant public health benefits. The study asserts that current air pollution levels continue to threaten communities, particularly poorer communities, and raise the risk for cardiovascular health concerns.

The study’s lead author, Majid Ezzati, from Imperial’s School of Public Health concludes that, “lowering the PM2.5 standard below the current level is likely to improve the health of the U.S. nation, and reduce health inequalities.”

Based on these conclusions - it may be time to reevaluate our standards for clean air in order to establish a healthier, more equitable America.