A new international study offers insights into the health risks posed by crops' absorption of "contaminants of emerging concern" (CECs) and flags knowledge gaps the authors say must be addressed.
CECs include pharmaceuticals, microplastics, engineered nanomaterials and PFAS (commonly known as "forever chemicals"). The researchers warn that even when present at very low concentrations, these chemicals can subtly alter plant physiology, disrupt soil health and pose wider environmental and human health risks.
"What's new here is the holistic perspective: we bring together evidence across chemical classes, environmental pathways, plant uptake mechanisms and societal impacts," said Audrey Moores, co-author of the meta-study and Professor of Chemistry at McGill.
"This review highlights major knowledge gaps, including the effects of chemical mixtures, long-term accumulation and sublethal impacts not captured by standard toxicity tests," she said. "Crucially, we show that reducing contamination at its source, through smarter chemical design and sustainable production, is essential, alongside improved regulation and monitoring."
Overlooked issues identified
The review was led by Laura J. Carter of the University of Leeds and conducted by an international research team whose members come from the United Kingdom, Israel, China, the United States and Canada.
The meta-study synthesized hundreds of laboratory, greenhouse and field experiments to compare how different CEC categories move through soils and plant tissues, how environmental conditions shape exposure and how contaminants accumulate in edible crops at environmentally realistic levels.
The study shows that CECs enter soils and crops through multiple, often overlooked pathways. This includes agricultural technologies like wastewater irrigation, biosolids, manure and agroplastics, many of which, paradoxically, stem from the desire to develop more sustainable agricultural practices.
Once taken up, CECs can move through plant vascular systems and reach leaves, fruits and roots.
The authors report that many CECs remain biologically active even at trace levels, influencing plant hormone pathways, microbial communities and nutrient cycling.
The researchers also found that CECs can drive antimicrobial resistance, interfere with plant biochemical processes and affect soil structure, with consequences for agricultural productivity and food quality. Persistent contaminants such as PFAS are especially prone to bioaccumulating in leaf tissues, the researchers said.
The review identifies several overlooked issues, such as co-contaminant interactions that can amplify or suppress toxicity, pathways that remain poorly studied, such as absorption through plant leaves ("foliar exposure"), and uneven global data gaps in understanding crop-specific risks.
Next steps
The authors call for new regulatory frameworks that account for the effects of mixing chemicals, realistic exposure scenarios and the role of CECs in antimicrobial resistance. They recommend long-term field monitoring, greater geographic diversity in crop studies and the development of degradable, non-persistent alternatives for agricultural and industrial use.
Moores noted that the review explicitly connects environmental findings with the principles of green chemistry, emphasizing that the safest and most effective long-term solution is to design chemicals and materials that degrade into harmless products and do not persist or accumulate.
"Safer chemicals can only be produced by having a design approach where we are thinking about end-of-life from the onset. Preventing pollution is far more effective than trying to clean it up later. Participating in this study was important to me as it illustrated with real-life examples the need for chemicals and materials design and discoveries to be better aligned with the realities of their applications and after-life," she said.
About this study
"Contaminants of emerging concern in agricultural soils: Current understanding, overlooked issues, and future priorities," by Laura J. Carter, Audrey Moores et al., was published in Thomas Review.
The research was funded by a United Kingdom Research and Innovation Future Leaders Fellowship and the Nanjing University International Collaboration Initiative.
