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Up in the Air
Understanding the chemistry of air pollution to reduce health risks
Polluted skyline over Fairbanks, Alaska

“In many ways, that’s where we’re going to move forward; we’re going to start doing compositionally based particulate matter regulation.”
- Richard Peltier

While exposure to air pollution poses known health risks, the underlying chemical mechanisms are thus far not fully understood. UMass Amherst researchers are working to map the chemical structures of air pollutants, test their effects on populations, and identify which pose the greatest health risk.

Currently, national emissions regulations are based on the total amount of pollutants present in a volume of air, yet the varying toxicity of these pollutants remains uncharted. Richard Peltier, a trained atmospheric chemist in the Department of Public Health is working to bring the data up to speed with a combination of lab simulation and field samples.

In many ways, that's where we’re going to move forward; we’re going to start doing compositionally based particulate matter regulation,” Peltier says.

Particulate matter describes the solid and liquid droplets that float in the atmosphere around us. These particles enter the air through both primary and secondary processes. Black, sooty material exiting a diesel engine tailpipe is an example of a primary source. Secondary sources, however, are much more varied: gases that enter the air are converted by sunlight into solid and liquid particles. Nickel and vanadium are examples of particulate matter that Peltier has found to be especially hazardous to human health, as they are associated with cardiovascular disease and even death.

Richard Peltier, Public Health
Peltier explains that air pollution depends on the context. Here in New England, the problem is smog: the conglomeration of millions of 2.5 micron-sized particles and ground-level ozone. Peltier says that about half of the particulate matter found in the Northeast is carried from coal power generation facilities in the Ohio River Valley and contributes substantially to air quality problems.

Peltier contends that New England’s issues are modest in comparison to places like Fairbanks, Alaska, where he is conducting research to help the community clear their air. While Peltier describes the landscape as “pristine,” he says that a long history of unrestrained wood burning has caused a massive air quality problem. Levels of pollutants in Fairbanks, which has a population of about 100,000, are about five times higher than the federal standard.

The local Fairbanks government recruited Peltier to help them determine the source of the problem, identify the toxins and improve the community’s air quality. Thanks to additional funding from the National Institutes of Health and the Health Effects Institute, Peltier’s new research laboratory at UMass has state-of-the-art equipment that enables extremely advanced testing. These new tools can take measurements at rapid time resolutions—every hour, whereas even the EPA’s equipment can only test samples every six days.

Peltier has built a photochemical aging chamber within the laboratory to conduct lab-based air pollution generation. He uses the chamber, which he calls the “smog chamber,” to simulate air pollution, modifying the exposure atmosphere with known toxins (such as nickel or vanadium) in order to test the responses on models. The chamber is surrounded by UV light, which is intended to simulate how sunlight and subsequent photochemical oxidation interact with pollutants. Peltier explains that few studies have incorporated this aging effect into air pollution exposure studies and he suspects it is the culprit for varying levels of toxicity.

“What I do in the lab is I expose to concentrations that are what you might get if you’re walking down the street,” Peltier says.

Peltier has devoted his research to exploring the chemistry of air samples ever since a former advisor told him that the chemical composition was irrelevant to the work. He says that he sensed something was amiss and decided to investigate. In Peltier’s case, veering off course brought him right where he needed to be. His research in understanding the chemical components within air samples led to the discovery of unusually high concentrations of nickel aerosol in samples taken in New York City, which inspired the citywide ban on residual fuel oil burning.

Attracted by the growing environmental health program, Peltier returned to UMass Amherst where he completed his undergraduate work, to expand his research into the chemistry of air pollution. Peltier says that the University allows him to approach his research from a unique perspective and that his cutting-edge instruments permit him to study air samples in ways that even the EPA does not. And simultaneously, by working in the Department of Public Health, Peltier is able to apply his research findings to study real-world health impacts.

“I try to split the difference between toxicology and aerosol science, and I’m sitting in what I view as a gap in the research field,” Peltier says.

Amanda Drane ‘12