Chlorinated Paraffins in Agroecosystems: A Silent Contaminant Threatening Soil Health and Crop Safety

Abstract Chlorinated paraffins (CPs), complex polychlorinated alkanes, are persistent organic pollutants (POPs) of growing concern. They are used as flame retardants, plasticizers, and lubricants, and enter agroecosystems via wastewater irrigation, sewage sludge, atmospheric deposition, and industrial runoff, exhibiting strong sorption, long half-lives, and bioaccumulative potential. While short-chain CPs (SCCPs) are regulated under the Stockholm Convention, medium- and long-chain CPs (MCCPs, LCCPs) are increasingly detected in soils, sediments, and crops but remain poorly categorized for toxicity and environmental fate. Evidence indicates that CPs can alter soil microbial diversity, inhibit enzymatic activity, disrupt nutrient cycling, and accumulate in plants, posing risks of food-chain transfer and human exposure. However, significant knowledge gaps persist regarding their long-term ecotoxicological impacts, degradation and transformation processes, and interactions with soil organic matter that govern their mobility, persistence, and bioavailability. This review discusses the existing literature on CP occurrence, fate, and ecological effects in agricultural environments, emphasizing analytical techniques and monitoring approaches for assessing soil-plant-human exposure, and identifies key research needs. Addressing these gaps is essential for improving risk assessment, guiding regulatory development, and protecting soil health, crop productivity, and food safety. CPs represent a “silent contaminant” in agriculture, threatening soil health, crop productivity, and food safety. Future research should integrate advanced detection methods, pilot-scale remediation strategies, and comprehensive risk assessments to inform policy, protect vulnerable populations, and safeguard sustainable agricultural production.