Exposure to South Portland tank emissions increases cancer, chronic illness risks, report says
South Portland residents who live within sight of more than 100 petroleum storage tanks may be breathing air that contains benzene at levels above the state’s health guideline, according to a six‑year monitoring report released by the Maine Department of Environmental Protection and the Maine Center for Disease Control. The study, which examined ambient air data collected from 2019 through 2025, found that long‑term average benzene concentrations at several tank farms exceeded the guideline by factors of two to 4.5, with the Citgo terminal recording concentrations twice the acceptable limit.
Benzene, a known carcinogen, can cause fatigue, dizziness and irregular heartbeat after short‑term exposure, and prolonged inhalation is linked to leukemia and other cancers. The report’s modeling suggests that the community’s lifetime cancer risk could rise from the baseline 33,000 cases per 100,000 people to 33,001 or 33,002, with the highest projected increase occurring near the Citgo terminal, where the risk approaches 33,003 per 100,000.
Acting State Toxicologist Thomas Simones, a co‑author of the study, cautioned that the elevated levels represent a theoretical risk rather than an immediate health crisis. “It’s not to say that if you’re above the guideline, there will be immediate cancer diagnoses in the community or increased rates,” he said. “It’s a theoretical risk that we like to keep low.” He added, “Here, we’re talking about that number going up to 33,001 or 33,002 out of 100,000 with these increased levels of benzene,” and noted that the figure climbs to 33,003 near the Citgo terminal.
The tanks are visible from nearby backyards, the Greenbelt trail, and a new playground at Pleasantdale, where children play just a short distance from the storage facilities. Residents have reported the scent of petroleum in the air while biking, running or walking the trail, and some say the odor is especially noticeable during the summer months.
Community members have voiced strong concerns. Georgia Deveres, who has lived in South Portland for nearly four decades, recalled her son’s recurring nosebleeds during his freshman year at a high school located near a tank farm. “Was it because he was running track and going to school in a high school that’s basically in a tank farm? I’m furious at myself. I sent my kid there,” she said. Later, at age 42, she received a alarming mammogram result indicating ductal carcinoma, a precursor to breast cancer. “I’m not saying I got breast cancer because of the tank fumes,” she added, “but I’m not not saying that it couldn’t have contributed.”
Rachel Burger, 89, has faced five separate cancers, including leukemia, and initially attributed her diagnoses to bad luck. “I previously chalked it all up to bad luck, but has started to wonder if they could be related to living near the tanks,” she said, noting that she can smell the petroleum even though the tanks are not visible from her yard.
Environmental experts are divided on the adequacy of the state’s exposure limits. Gail Carlson, a professor of environmental studies at Colby College, argues that there is no safe level of benzene exposure. “If you can see the tanks, you absolutely should be concerned,” she asserted. “There is no safe exposure to chemicals like benzene… At what level is risk acceptable? At what level is risk actionable?”
Rich Campbell, a consultant with Campbell Environmental Group who has worked for several of the oil companies mentioned in the study, takes a different view. He said he would not be overly worried if he were assessing the data for a site his firm was hired to remediate. “The solution to pollution is dilution,” he remarked, adding, “Those are, you know, very high levels… You don’t reach that level of contamination in ambient air.”
The report also notes that the total permitted emissions from petroleum companies operating in South Portland exceed 360 tons of volatile organic compounds per year. While Global Partners has implemented odor‑reduction measures and claims its terminal contains little benzene, the other firms have not responded to inquiries about their contributions.
Historical context shows that the same companies have faced regulatory action in the past decade. The EPA previously sued Sprague, Global and Gulf Oil for violating longstanding emissions caps on volatile organic chemicals, resulting in fines and orders to reduce releases.
City officials plan to address the findings at a workshop on October 27, and a community gathering is scheduled for October 15 at First Congregational United Church of Christ on Meeting House Hill. Chelsea Byun, a longtime resident and former Press Herald editor, said the new data have reignited public pressure. “We need to get all of our leaders together to actually do something about this now that we have clear evidence that the tank farms are dumping pollution into our neighborhoods,” she said.
The state’s guideline sets a cancer risk threshold of one in 100,000 for continuous exposure over a 70‑year period, a standard that is ten times less protective than the U.S. Environmental Protection Agency’s one‑in‑a‑million threshold. Whether the observed benzene levels constitute an actionable risk remains a point of debate as residents, scientists and regulators continue to evaluate the long‑term health implications of living beside South Portland’s extensive tank farms.
