Volunteer scientist Yuri Gorby with one of the low-cost air-pollution sensors in Belmont County, Ohio.
Volunteer scientist Yuri Gorby with one of the low-cost air-pollution sensors in Belmont County, Ohio. Credit: Leatra Harper / FreshWater Accountability Project

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A recent study in a heavily fracked Ohio county found that regional air quality monitors failed to capture variations in pollution at the local level, spotlighting the need to address gaps in data on fossil fuel emissions.

Existing Environmental Protection Agency monitors track broad regional trends in air quality. But they don’t reflect differences from place to place within an area. And their reporting often misses short-term spikes that can affect human health, said lead study author Garima Raheja at Columbia University.

“Health is not a broad regional effect,” Raheja said. Health impacts from pollution often depend on more local conditions and can vary “day to day, hour to hour,” she noted.

The project began when co-author Leatra Harper at the FreshWater Accountability Project and others asked the American Geophysical Union’s Thriving Earth Exchange for help in establishing current baseline emissions for the area. The program connected them to Raheja and other scientists.

In addition to Raheja and Harper, study authors are at the AGU Thriving Earth Exchange, Columbia University, Carnegie Mellon University, the Massachusetts Institute of Technology and Wayne State University. Additional researchers are at community advocacy organizations, including the FreshWater Accountability Project, FracTracker and the Environmental Health Project. 

The team developed a grassroots, community-based network of low-cost air monitoring stations. Each monitoring station used PurpleAir monitors. The monitors cost a couple hundred dollars each, compared to up to $100,000 or more for equipment at the regional EPA air monitoring stations, Raheja said.

The equipment measures levels of fine particulate matter, or PM. Corrected data from PurpleAir monitors correlate strongly with those from reference-grade monitors, studies have found. Tweaks to the monitors also let the network track levels of volatile organic compounds, or VOCs. And community members kept logs about physical symptoms or things they noticed in the area. 

Additionally, the researchers made an inventory of all pollution emissions already permitted for the area. The data let them model how pollution could travel in the area.

“We wanted to show what people are actually experiencing,” Raheja said. “And we wanted to show some examples of plumes from different sources.”

General trends in emissions levels were similar for the EPA monitoring stations and the local monitors. However, there were substantial variations in the emissions levels recorded by the two types of stations. Those results showed that exposure to pollutants varies throughout the study area. 

The results also showed multiple cases when spikes in certain emissions tracked closely with log entries about residents’ health symptoms or other events in the area, such as pipeline pigging or compressor station blowdowns.

The researchers’ study was in the journal Environmental Research Letters on May 25.

Why track emissions in Belmont County?

Belmont County had more than 700 oil and gas wells completed from 2011 through 2021, state records show. Most of those wells were drilled into the Utica Shale to produce wet gas. It includes methane along with other petroleum compounds.  

Fugitive methane emissions are a potent greenhouse gas. Other emissions from the oil and gas industry fall into the category of air toxics or produce ground-level ozone, which irritates the lungs. A variety of health impacts can result from both chronic, long-term pollution and from shorter-term spikes in emissions.

“We’re seeing some of those health impacts already with the oil and gas industry,” Harper said. Several studies have shown health impacts among people living near fracked, horizontal wells. And people in the area have reported anecdotal symptoms, she said.

“We really need to establish accountability for the polluters,” Harper said. Regulatory authorities often come out too late to detect emission spikes that have happened on nights or weekends. Or, regulators have been dismissive about residents’ concerns when they lacked data on local emissions levels, she said.

Another concern was developing a baseline level of emissions before the addition of more wells or a massive petrochemical plant planned for Belmont County. Developer PTTGC Global Chemicals has yet to make a final commitment on the project.

What do others say about the study and local air quality monitoring?

“I see a huge need for these kinds of networks,” said Victoria Petryshyn, an associate professor of environmental studies at the University of Southern California, who hails from Ohio. She did not work on the research study.

Many areas have micro-climates where air quality varies. “In an area like the Ohio River Valley, with lots of unconventional oil and gas production, low-cost monitoring is key. The EPA doesn’t have the budget to monitor every block, so the nuances in the air pollution picture are missed.”

“All in all, I thought it was a really good approach to problem-solving,” Petryshyn said. Ideally, monitoring for ozone and nitrous oxides could also be added to a network, she suggested. On sunny summer days, VOC levels can drop, “not because they are not being produced, but because they are rapidly converted to another pollutant.”

Petryshyn commended the scientists for treating “the citizen volunteers as partners, giving them agency in the monitoring process and results.” Also, she said, “they recognized and valued local knowledge. As a scientist, I can spend a lot of time and money doing some models to see where VOCs or PM might travel on windy/still days. Or I could go ask a local where the air seems bad.”

Are government agencies likely to accept local monitoring results?

The U.S. Environmental Protection Agency already has recognized the importance of data from local monitoring networks with PurpleAir sensors for supplementing its information. For example, sensors for particulate matter have enhanced EPA tools for tracking wildfires and smoke.

The Franklin County Public Health Department and Mid-Ohio Regional Planning Commission also are using the sensors to measure differences in air quality across several zip codes in the Columbus area. Brooke White, who was then the sustainability program manager for the regional planning commission, spoke about the project at the December 2021 meeting of the American Geophysical Union.

Use of the sensors for tracking VOCs is more cutting edge, Raheja said. But “there’s a lot of confidence” in the sensors showing increases or decreases in exposure, she added. And spikes tracked well with residents’ reports of symptoms, such as nausea.

Is industry likely to accept local monitoring results?

“While we respect those conducting citizen science, we strongly disregard a report funded and conducted by those who oppose the natural gas industry whose conclusion is anti-natural gas,” said Mike Chadsey, spokesperson for the Ohio Oil and Gas Association. The group “stand[s] by the U.S. EPA’s monitors and their data,” he added, claiming that they haven’t shown an environmental or health risk from oil and gas development.

“We are showing that the limited scope of the EPA monitors is not sufficient for characterizing air pollution in this region, which is a conclusion based entirely on the objective, scientific analysis conducted during this study,” Raheja said. She also challenged Chadsey’s assertion about health and environmental risks, noting that EPA statements and other peer-reviewed studies link numerous health impacts to exposure to pollution from the oil and gas industry.

As for the accusation of bias, Raheja noted that the article appeared in a peer-reviewed journal, where independent experts review studies anonymously without knowing who did the work. The study acknowledges a $40,000 grant from the Community Foundation for the Alleghenies, but there were no preconceived notions or expectations that would otherwise compromise the science, Harper said. 

Additional support came from the National Science Foundation and the Heinz Endowments. The American Geophysical Union’s Thriving Earth Exchange provided ongoing scientific and project management support.

Kathiann M. Kowalski

Kathi is the author of 25 books and more than 600 articles, and writes often on science and policy issues. In addition to her journalism career, Kathi is an alumna of Harvard Law School and has spent 15 years practicing law. She is a member of the Society of Environmental Journalists and the National Association of Science Writers. Kathi covers the state of Ohio.