A cancer-causing chemical is more prevalent in Louisiana than previously thought, study says
A new study using mobile labs found levels higher than what the EPA has estimated. Researchers from Johns Hopkins University in Baltimore, Maryland, have found that a cancer-causing chemical, ethylene oxide, is more prevalent in the air along the Mississippi River corridor between Baton Rouge and New Orleans than previously thought. The researchers found concentrations of the chemical were 1.5 times to more than 19 times greater than U.S. Environmental Protection Agency estimates. They examined 13 census tracts along the east banks of Ascension, Iberville, St. James and St. John the Baptist parishes, which have all the largest emitters in the state. All 13 areas exceeded EPA estimates for the chemical and 12 were found to have higher cancer risk than EPA standards. The findings suggest significantly higher cancer risks for people who live near facilities that manufacture and use the chemical.
Published : 10 months ago by David Mitchell in Environment
A chemical known to increase the risk of cancer is far more prevalent in the air along the Mississippi River corridor between Baton Rouge and New Orleans than previously thought, a new study has found. Researchers from Johns Hopkins University in Baltimore, Maryland, found concentrations of ethylene oxide that were 1.5 times to more than 19 times greater than U.S. Environmental Protection Agency estimates show. The team of university researchers examined 13 census tracts along the east banks of Ascension, Iberville, St. James and St. John the Baptist parishes. Those parishes are part of a region that has 12 of the 15 industrial facilities that report emitting ethylene oxide into the air in Louisiana and has all the biggest emitters in the state. The researchers collected their data by driving two mobile labs with advanced optical equipment that continuously measured the air along major highways for 27 days between late Jan. 31 and Feb. 16, 2023. When not moving, one of the mobile labs was parked in the Donaldsonville area and continued collecting data, according to an advance copy of a published study.
All 13 tracts exceeded EPA estimates for ethylene oxide. And 12 were found to have ethylene oxide concentrations posed a greater cancer risk than EPA standards allow — in some cases by a significant amount. This EPA minimum acceptable level is an added cancer risk of 1 in 10,000. In its regulatory efforts, EPA says it strives for a cancer risk of 1 in 1,000,000. The researchers found the highest average concentrations within within 1 kilometer, or a little over a half-mile, of the facilities that produce the chemical. But they also found concentrated ethylene oxide plumes that went as far as about 7 miles away. They noted one plume that fell on the Pelican Point community more than four miles from the likely source and suggested that the plume findings should prompt additional long-term measurements as far as 7 miles out from emitters, including around local schools like East Ascension High School.
In a statement Tuesday, Johns Hopkins officials said the findings "suggest significantly higher cancer risks for people who live near facilities that manufacture and use ethylene oxide." "I don’t think there’s any census tract in the area that wasn’t at higher risk for cancer than we would deem acceptable," said Peter DeCarlo, a Johns Hopkins University associate professor of Environmental Health and Engineering. "We expected to see ethylene oxide in this area. But we didn’t expect the levels that we saw, and they certainly were much, much higher than EPA’s estimated levels." Census tracts are small geographic divisions of parishes that federal census officials use to develop population and other demographic statistics. But EPA reporting through its National Air Toxics Assessment also relies on these tracts for granular estimates of cancer and other health risks from air pollution.
The study's authors found tracts encompassing St. Gabriel and Carville in eastern Iberville Parish had the highest measured ethylene oxide concentrations and were furthest above the EPA's acceptable cancer risk level. Other leading tracts both in ethylene oxide concentrations and divergence from EPA estimates include the Dutchtown, Geismar, Sorrento, southern Gonzales and Burnside areas of Ascension Parish, and the Reserve and Belle Point areas of St. John. On average, the researchers found the concentration of the chemical was roughly twice the EPA's acceptable amount. But, they found plumes of ethylene oxide that were significantly more concentrated than the average figures they developed. Nearly half of the 192 plumes detected had concentrations that were at 1 part per billion or greater, a level that is 92 times what the EPA says is safe for chronic exposure.
The authors singled out an area bounded by La. 73, La. 30, River Road and Ashland Road in the Geismar and southwestern Gonzales areas as containing a cluster of facilities that were responsible for 50 ethylene oxide plumes of 1 ppb or greater during the period of testing. The area is home to BASF, Shell Chemical and Rubicon. Ellis Robinson, the paper's lead author and an environmental engineer at Johns Hopkins, explained that the significance of the study is that it was able to collect actual measurements of ethylene oxide at minute concentrations that EPA says constitutes safe for long-term exposure. EPA risk estimates are based on self-reported industry emissions data that is then modeled to develop risk figures.
Ethylene oxide is a sweet smelling, colorless gas that is used to sterilize medical equipment and fumigate spices. In chemical production, it's used as an intermediate to make anti-freeze, textiles, detergents, polyurethane foam, solvents and other products. After years of study, in December 2016, the EPA determined ethylene oxide was a human carcinogen for lifelong inhalation and was 30 to 60 times more toxic than federal assessments from 1985 had concluded. The Johns Hopkins researchers say that EPA data show ethylene oxide constituted 68% of the total cancer risk in the river corridor from air pollution. The high cancer risk means EPA has determined safe long-term exposures are tiny and beyond the ability of standard methods to measure easily. The EPA's risk analysis says the minimum safe level is 10.9 parts per trillion.
One part per trillion is the equivalent of 1 drop of water in 20 Olympic-sized swimming pools, according to Michigan state regulators. The Johns Hopkins study was financed by Bloomberg Philanthropies' Beyond Petrochemicals campaign, which advocates for a halt of the "rapid expansion of petrochemical and plastic pollution in the United States." Robinson, the Johns Hopkins researcher, said the nonprofit provided funding for the work but was not involved in the study's design, conduct or analysis. The study has been published in the peer-reviewed academic journal, Environmental Science & Technology. In an email, DeCarlo said the analysis and the related paper were reviewed by five experts in the field before it could be published.
Bloomberg officials and community and environmental groups said the findings demonstrated what they've been saying for years about chemical pollution in the river region and the need for fence-line monitoring. Kimberly Terrell, staff scientist and director of community engagement at Tulane Environmental Law Clinic, said in a joint statement with Bloomberg that the "ground-breaking work reveals the danger of relying solely on pollution values estimated by industry." "To ensure public safety, LDEQ must require all toxic emissions to be measured, not estimated, at the fence line of polluting facilities,” she added. "We're hoping the politicians will believe scientific data over lobbyists' wish list," Gail LeBoeuf, co-founder and director of the St. James Parish community group Inclusive Louisiana, said in the Bloomberg statement. "Johns Hopkins' report shows not only the fence line communities are harmed by cancer causing ethylene oxide, but neighboring communities seven miles away from a facility producing ethylene oxide."
Greg Bowser, president and CEO of the Louisiana Chemical Association and Louisiana Chemical Industry Alliance, said it is hard to comment on the study without know how researchers calibrated their monitoring devices to measure very small concentrations of the chemical. He also faulted the study for not accounting for background levels of the chemical outside the industry area as a comparison point for the localized findings. The American Chemistry Council has estimated ethylene oxide's natural background level is 15 times higher than EPA's standards, Bowser said. "(Ethylene oxide) is present in the environment and is created by various sources, including vehicle exhaust, plant and soil metabolism, and even fruit ripening," Bowser said. "Without knowing the background levels of these readings, we have nothing to contextualize the study's results."
In response to Bowser's statement, DeCarlo, the study's senior author, said the conclusions of the Chemistry Council "are not peer reviewed in the same way" as Johns Hopkins' work was and contain "errors in the assessment of background concentration and potential sources or ethylene oxide." Industry groups and some state regulators, including those in Texas and Louisiana, have argued EPA's cancer risk findings greatly overstated the actual risk posed to the public and have unsuccessfully fought to have the greater risk levels applied to air pollution standards. In April, EPA announced it would be requiring major reductions in emissions of ethylene oxide and five other carcinogenic chemicals that will affect 51 facilities in the state, cutting cancer risk from toxic air pollution nationwide by 96%.
Topics: Data, Governance-ESG