Ten times worse than benzene — California updates its science on two air contaminants

7 min Click here to listen to this article Share via Close extra sharing options Email Facebook X LinkedIn Threads Reddit WhatsApp Copy Link URL Copied! Print 0:00 0:00 1x This is read by an automated voice. Please report any issues or inconsistencies here. Two toxic air contaminants present in California’s ambient air, acrolein and ethylene oxide, appear to be much stronger carcinogens than previously known, California environmental health officials announced Thursday. The draft finding from the state’s Office of Environmental Health Hazard Assessment finds the chemicals may pose an estimated cancer risk more than 10 times higher than benzene, a serious carcinogen linked to leukemia and other cancers. It is the first step in a review process before final risk values are adopted. “If the early air monitoring results bear out, and if the draft cancer values developed are close to what eventually becomes final, then each air contaminant poses an unacceptable cancer risk,” said Kris Thayer, OEHHA’s director. The update reflects the state’s evolving understanding of its most dangerous pollutants, which has shifted over the decades from visible pollutants, such as smog, to more invisible ones that cause cancer, heart disease and other health harms. It comes only two months after the Trump administration’s Environmental Protection Agency moved to roll back standards on ethylene oxide, or EtO, in an effort to save millions of dollars in compliance costs for facilities that use the chemical for medical sterilization. The administration said it acted to “safeguard the supply of essential medical equipment,” but experts said the move will also expose more people to health risks. It also follows a new national report from the American Lung Assn. that found 82% of Californians live in counties with unhealthy air, nearly double the national average. “This is an important step to better understanding the harms of pollutants impacting Californians’ health,” said Will Barrett, assistant vice president for nationwide clean air policy at the American Lung Assn., who reviewed the state’s findings for The Times. “Following the latest available health science to determine risk is crucial to protecting health.” An estimated 50% of sterile medical devices in the U.S. are treated with ethylene oxide. It is also a known carcinogen. Ethylene oxide is a colorless gas often used in the sterilization of medical devices, particularly those that can’t be cleaned using steam or radiation. Acrolein can be formed when materials burn, such as cigarettes, e-cigarettes and vapes, wood, plastics and gasoline for cars, trucks, ships and aircraft. It can also be released by cooking fats and oils at high temperatures, and has been found in water produced by oil and gas operations and is an ingredient in some pesticides used in irrigation canals. People can take steps to protect themselves from acrolein exposure in everyday life by avoiding smoking tobacco or using e-cigarettes and vaping products, avoiding smoke from fires or exhaust from diesel and gasoline vehicles and equipment — much of which can also help reduce exposure to ethylene oxide, officials said. When cooking with oils or fats, people should avoid very high temperatures and use a range hood fan when possible. While both chemicals have been present in the state’s air for years, the new assessments from OEHHA are based on the latest science on health risks, officials said. Both acrolein and ethylene oxide were found to pose an estimated cancer risk exceeding 800 in 1 million — on par with the cancer risk that diesel exhaust was estimated to pose when it first emerged as a major public health concern in the 1990s, the agency said. In response to the findings, Gov. Gavin Newsom’s May budget revision, released Thursday, includes $2.5 million in funding for the California Air Resources Board and OEHHA in support of research to help reduce people’s exposure to acrolein and ethylene oxide. The funding will help the state identify and track major sources of the chemicals and turn the findings into public health policy outcomes, officials said. OEHHA’s assessment provides the first cancer risk value for acrolein since it was classified as probably cancer-causing to humans by the International Agency for Research on Cancer in 2020. Ethylene oxide was already identified as a carcinogen by the state, but the new assessment updates its risk levels based on the new research. The risk calculations are based on air monitoring data, which vary across the state depending on location, nearby sources and other factors. Officials said the findings underscore the state’s efforts to strengthen environmental protection measures for residents at a moment when federal officials seek to loosen them. “Especially in light of some of the national rollbacks we’re seeing on protections for public health, it really underscores how important the work that we’re doing here in California is,” said Courtn

Ten times worse than benzene — California updates its science on two air contaminants

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