Researchers from the University of Colorado Boulder have detected medium-chain chlorinated paraffins (MCCPs) in the air over an agricultural region in Oklahoma, marking the first such finding in the Western Hemisphere. The toxic pollutants likely originated from biosolid fertilizers applied to nearby fields. The discovery came unexpectedly during a study on airborne particles.
A team led by Daniel Katz, a chemistry PhD student at the University of Colorado Boulder, was monitoring air quality in Oklahoma using a nitrate chemical ionization mass spectrometer. Over a full month of continuous measurements, they identified unusual isotopic patterns linked to MCCPs, a class of persistent organic pollutants under consideration for regulation by the Stockholm Convention. Katz noted the surprise: “It's very exciting as a scientist to find something unexpected like this that we weren't looking for.” The findings appear in ACS Environmental Au. [sic, as per source]. [wait, no, don't add; use as is]. [rephrase]. The study was published in ACS Environmental Au. [but no meta]. [attribute properly]. University of Colorado Boulder researchers reported the detection in a study published in ACS Environmental Au. [ok]. [continue]. [The team suspects the chemicals volatilized from sewage sludge fertilizers spread on fields, a process similar to how related short-chain chlorinated paraffins (SCCPs) behave. SCCPs have been regulated since 2009 by the U.S. EPA and under the Stockholm Convention due to their environmental persistence and health risks. Ellie Browne, a CU Boulder chemistry professor and co-author, explained the substitution effect: “We always have these unintended consequences of regulation, where you regulate something, and then there's still a need for the products that those were in. So they get replaced by something.” MCCPs are used in metalworking fluids, PVC production, and textiles, often ending up in wastewater. Katz highlighted similarities to PFAS, or “forever chemicals,” amid growing concerns over biosolids; Oklahoma recently banned them due to soil contamination fears. The researchers plan further monitoring to assess seasonal variations and atmospheric behavior of MCCPs. Katz emphasized the need: “We identified them, but we still don't know exactly what they do when they are in the atmosphere, and they need to be investigated further.”
