Tens of thousands die from air pollution in the U.S.

Air pollution claims millions of lives around the world, mostly in developing countries, according to the World Health Organization. But that doesn’t mean people in developed countries are shielded from the effects of toxic air. Far from it.

In the United States, the world’s richest nation, as many as 30,000 people may die from causes triggered or exacerbated by airborne pollutants, say researchers from Imperial College London in the United Kingdom and the Center for Air, Climate and Energy Solutions at Carnegie Mellon University in the U.S.

High levels of air pollution in some urban areas also impact life expectancy, they warn.

They have reached this conclusion after analyzing concentrations of fine particle matter, or PM2.5, based on data gathered from over 750 air-quality monitoring stations across the U.S. The scientists then compared that with other sources of air pollution data, including satellite images, they explain in a new study.

Mainly emitted by gas-guzzling vehicles as well as fossil fuel-burning power plants and factories, these tiny airborne particles, which are invisible to the naked eye as they are 30 times smaller than the width of a human hair, can penetrate into lungs with ease. Once they accumulate in people’s bodies, they can cause or worsen a variety of ailments from pulmonary disease to cancer. Toxic air has also been linked in recent years to early-onset Alzheimer’s in adults and learning disabilities in children.

“The amount of this fine particle pollution in the US has declined since 1999. The current US annual PM2.5 standard is set at 12 microgram per cubic meter of air (ug/m3),” they explain.  However, the researchers add, their research shows that “at levels between 2.8ug/m3 and 13.2ug/m3, which is mostly below the current standard, air pollution was associated with an estimated 15,612 deaths in females, and 14,757 deaths in men.”

The recorded deaths were caused by heart- and lung-related disorders, including cardiac arrest and asthma. “These deaths would lower national life expectancy by 0.15 years for women, and 0.13 years for men,” they write. “The life expectancy loss due to PM2.5 was largest around Los Angeles and in some southern states, such as Arkansas, Oklahoma and Alabama,” the scientists elucidate.

Of course, determining the exact cause or causes of diseases and premature death can be a daunting task as numerous factors tend to be involved from genetics to lifestyle choices such as diet. Yet the scientists stress that their study indicates that air pollution is likely a significant factor.

“We’ve known for some time that these particles can be deadly. This study suggests even at seemingly low concentrations — mostly below current limits — they still cause tens of thousands of deaths,” says Prof. Majid Ezzati, the study’s lead author.

Nor is the United States the only rich nation where air pollution causes diseases and premature deaths. “US PM2.5 concentrations are generally lower than those in many Europe cities — which suggests there may also be a substantial number of deaths in Europe associated with air pollution,” Ezzati says.

To make matters worse, air pollution generated in one country or area can affect people living in another. Researchers at the Massachusetts Institute of Technology have found that if China succeeds in reducing its CO2 emissions by 2030, as the country’s government has pledged to do, there will be 2,000 fewer premature deaths in the U.S., and thousands of fewer deaths in South Korea and Japan as well.

The reason is that fewer airborne pollutants will be swept downwind from China to neighboring countries. “It reminds us that air pollution doesn’t stop at national boundaries,” observes Valerie Karplus, a assistant professor of global economics and management at MIT.