For the first time, scientists have found medium-chain chlorinated paraffins (MCCPs) drifting through the air over Lamont, Oklahoma a startling discovery with major environmental and health implications. The study published in ACS Environmental Au marks the first detection of MCCPs in the Western Hemisphere, challenging assumptions about where these pollutants occur and how they travel.
From Sewage Sludge to Sky
Researchers believe the source may lie in biosolid fertilizers nutrient-rich sludge from municipal wastewater treatment plants often spread over farmland. When applied to fields, fine particles laced with MCCPs can be lifted by wind or released as gases in warm sunlight, entering the atmosphere and traveling over long distances.
Daily temperature swings appear to influence MCCP levels, with peaks during the warmer daylight hours. This suggests that farming practices, combined with chemical volatility, may be driving airborne contamination.
The Unintended Fallout of Chemical Bans
The rise of MCCPs is partly a result of a 2009 U.S. ban on short-chain chlorinated paraffins (SCCPs), which are also toxic and persistent in the environment. In replacing SCCPs, manufacturers turned to MCCPs for use in plastics, paints, metalworking fluids, and flame retardants without fully assessing the environmental risks.
Health Risks and Regulatory Gaps
While the health effects of MCCPs on humans are not fully understood, studies suggest they can cause liver stress, hormone disruption, and developmental harm in animals. Like PFAS “forever chemicals,” MCCPs persist in the environment and accumulate in fatty tissues, potentially moving up the food chain.
Despite these dangers the U.S. currently has no air quality standards for MCCPs, and personal exposure monitoring is rare. Experts warn this leaves communities vulnerable.
Next Steps: Tracking and Policy Action
The research team plans to sample soils, sludge, and air across multiple seasons to map MCCP spread and identify contamination hotspots. Lawmakers in some states are already considering restrictions on biosolid use, particularly where industrial pollutants are present.
Environmental scientists are also urging industry to develop non-chlorinated chemical alternatives to reduce long-term risks.