Sean Reilly, E&E News, February 23, 2021
Older adults face a variety of health perils from long-term exposure to three common pollutants, including those in tailpipe emissions, even at levels below EPA air quality standards, researchers have found.
Experts note that the study’s findings could add to the pressure on EPA to tighten the air quality regulations.
The results of the massive new study of some 63 million Medicare enrollees suggest that the current standards for all three “are insufficient,” Mahdieh Yazdi, a Harvard University researcher and the study’s lead author, said in an email to E&E News this morning.
For example, nitrogen dioxide — found in the tailpipe exhaust of cars, buses and trucks — was linked to a higher risk of hospitalization for one type of stroke; heart palpitations; and atrial fibrillation, a condition in which the heart’s upper and lower chambers beat out of sync, according to the paper, published online yesterday in Circulation, an American Heart Association journal.
Ground-level ozone, the main ingredient in smog, was tied to increased odds of contracting pneumonia, while exposure to the fine particulates commonly known as soot was associated with more hospital admissions for all of those ailments as well as one type of heart attack.
“The risk persists even at levels below current national and international guidelines,” Yazdi and the other authors, based at Harvard, Emory University, and institutions in China and Brazil, wrote in the paper.
For the study, they tracked all fee-for-service Medicare enrollees aged 65 or older who lived in the lower 48 U.S. states from 2000 to 2016 in the context of hospital admissions and their exposure to the pollutants in question. The findings could have regulatory consequences because EPA maintains ambient air quality standards for all three pollutants, subject to periodic reviews based on the latest research in their health and environmental effects.
Under the Trump administration, the agency had opted against changes to the soot and ozone standards; states and environmental groups are challenging those decisions in court on the grounds that the scientific evidence already warranted tightening the existing thresholds. The Biden administration plans to review both of those determinations but has not spelled out how at this point.
Most interesting are the findings related to exposure to nitrogen dioxide, George Allen, chief scientist for Northeast States for Coordinated Air Use Management, a Boston-based consortium of air pollution regulators, said in an email after reviewing the paper.
“This could put more pressure to seriously consider” a stricter air quality standard for the pollutant, Allen wrote.
EPA’s latest review of the primary standards for nitrogen dioxide ended in 2018, also with a decision to leave the current limits in place. Under the Clean Air Act, primary pollutant standards are geared to protecting public heath. For nitrogen oxides, it is 53 parts per billion; for fine particulates, they are 12 micrograms per cubic meter of air. As the authors note in the paper, EPA does not have a yearly primary standard for ozone, but the observed levels were below the official 70-ppb benchmark, which is calculated on an eight-hour average.
