- The Washington Times - Thursday, June 29, 2017

Air pollution levels that meet national standards are still high enough to contribute to early deaths among the elderly and minorities, according to a wide-ranging study in a peer-reviewed medical journal. 

The findings by the Harvard T.H. Chan School of Public Health published Thursday in the New England Journal of Medicine prompted the study’s researchers and the journal’s editors to criticize Trump administration budget cuts to environmental policies and agencies.

The Harvard researchers analyzed causes of death related to exposure to air pollutants for nearly 61 million Medicare and Medicaid beneficiaries, from 2000 to 2012.

The pollutants analyzed included particulate matter — small particles and liquid droplets in the air — no bigger than 2.5 micrograms, identified as PM2.5 and known to have negative health effects on the heart and lungs.

PM2.5 is found in emissions from construction sites, unpaved roads, fields, smokestacks and fires. They form in the atmosphere in reaction to sulfur dioxide and nitrogen oxide, pollutants from power plants, industries and automobiles, according to the Environmental Protection Agency.

Researchers also compared rates of decreased life-expectancy linked to exposure to ozone gas, which can damage the lungs, cause chest pains and worsen chronic respiratory diseases such as asthma, the EPA says on its website.

Since 1970, the EPA established national goals to cap rates of PM2.5 called the National Ambient Air Quality Standard (NAAQS). The standard is reevaluated every five years, with the goal in 2012 to limit rates to 12 micrograms.

From 2000 to 2015, the EPA noted a 37 percent decrease of PM2.5 in the air.

In the study “Air Pollution and Mortality in the Medicare Population,” the Harvard researchers found that the death rate increased by 7.3 percent for every 10-microgram increase of PM2.5, which translates to 120,000 fatalities related to exposure among people age 65 and older, the study’s lead author Qian Di explained to Reuters.

Francesca Dominici, a Harvard professor of biostatistics and co-author of the study, said the EPA has done an admirable job in reducing the number of pollutants nationally to today’s low levels, but the study focused on the cause of mortality in areas where PM2.5 levels were below the standard, showing that the accepted level needs to be reevaluated.

“Indeed, in the last 20 years we have been seeing the level of pollution going down quite dramatically,” Ms. Dominici told The Washington Times. “So what the paper is showing is we need to continue to take this issue very seriously.”

“I can tell you for sure what we should not do,” she added, “which is to take steps backwards toward this issue.”

An accompanying editorial in the New England Journal of Medicine criticized President Trump and his administration for taking steps that would cut funding from the EPA and implement policies that work against environmental protection, such as opening leases on new coal mines and dismantling guidelines that would reduce emissions from coal-fired power plants.

Its authors — Rebecca Berger, Ramya Ramaswami, Caren G. Solomon and Dr. Jeffrey M. Drazen — said funding cuts to the EPA would harm the agency’s ability to enforce regulations, and they denounced the president’s decision to withdraw from the Paris Climate Agreement, commitments by 192 nations to reduce greenhouse gas emissions contributing to climate change.

“The increased air pollution that would result from loosening current restrictions would have devastating effects on public health,” the editors wrote.

The president has said his environmental policy decisions were made in the interest of building up the American economy.

In an emailed response, an EPA spokesman attacked the study, saying the conclusions are not “supported by direct evidence.”

“It uses an ‘all-cause mortality,’ which accounts for all deaths regardless of the cause, and does not attribute deaths related to a terminal disease, car crash or other factors. It also fails to take into account ‘individual data on behavioral risk factors’ such as smoking, obesity and income. Additionally, the study does not include the underlying data. The authors should release the data to better inform the public of the merits of its conclusions,” the spokesman wrote.

In the study, researchers relied on public data from the EPA, NASA, the National Oceanic and Atmospheric Administration and on claims data from Medicare and Medicaid.

Ms. Dominici, in response to the EPA’s comments, said the researchers examined “over hundred variables that measure individual level risk factors,” including smoking, obesity and income, and that the five leading causes of death among seniors — cardiovascular disease, cancer, stroke, chronic obstructive pulmonary disease and influenza — have all been attributed to long term exposure to air pollution.

“Deaths from car crashes account for less of 1% of the deaths among our senior citizens,” she wrote in an email to the Washington Times.

The amount of data the researchers accumulated was so large, they had to use the entire Harvard computer network to analyze it, running their computations during school breaks of Christmas, New Year’s and Lunar New Year so as not to compete with anyone else using the servers.

The researchers were so exacting that they were able to estimate the ambient level of pollution in every single Zip code in the United States, Ms. Dominici said. They focused on mortality levels linked to exposure to air pollutants in areas where levels of PM2.5 were below the national average.

The researchers recorded rates of PM2.5 across the nation that ranged from as low as 6 micrograms per cubic meter to as high as 15, noting the highest concentrations of PM2.5 were found in California and the eastern and southeastern United States.

The mass of data also allowed researchers to examine the effects of the air pollutants on sub-groups, finding that men — in particular black, Asian and Hispanic — and those of a low socioeconomic status that made them eligible for Medicaid, had higher estimated risks of death from exposure to to PM2.5 than the general population.

The authors recommend lowering the annual NAAQS to reduce public health risk, especially among the most affected subgroups.

“With air pollution declining, it is critical to estimate the health effects of low levels of air pollution — below the current NAAQS — to determine whether these levels are adequate to minimize the risk of death. Since the Clean Air Act requires the EPA to set air-quality standards that protect sensitive populations, it is also important to focus more effort on estimating effect sizes in potentially sensitive populations in order to inform regulatory policy going forward,” the authors wrote.

Update: This article was updated on June 30 to reflect a response from the EPA and an additional response from study co-author Prof. Francesca Dominici.

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