By McGill University
April 3, 2026

Researchers uncover how trace contaminants move through crops and soils, quietly influencing plant biology and agricultural systems in ways not fully understood.

A sweeping international analysis is raising new concerns about what may be quietly entering our food supply. Scientists report that crops can absorb “contaminants of emerging concern” (CECs), a broad group of modern pollutants that includes pharmaceuticals, microplastics, engineered nanomaterials, and PFAS (commonly known as “forever chemicals”).

Even in trace amounts, these substances can interfere with plant growth, reshape soil ecosystems, and potentially move into the human diet.

Unlike traditional pollutants, many CECs are not routinely monitored or regulated in agriculture. Yet the study shows they can enter farmland through unexpected routes, including recycled wastewater, treated sewage sludge, manure, and plastic-based farming materials. Some of these practices are widely promoted as sustainable solutions, which raises a difficult question about hidden trade-offs in modern agriculture.

“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 involved researchers from the United Kingdom, Israel, China, the United States, and Canada.

To reach their conclusions, the team analyzed hundreds of lab, greenhouse, and field studies. They compared how different types of CECs move through soil and plant tissues, how environmental factors influence exposure, and how these substances build up in edible crops under realistic conditions.

The findings show that CECs reach soil and crops through several pathways that are often underestimated. These include practices such as wastewater irrigation, the use of biosolids and manure, and agroplastics. Many of these methods are intended to support more sustainable agriculture but may unintentionally introduce contaminants.

After entering plants, CECs can travel through internal vascular systems and accumulate in leaves, fruits, and roots.

The researchers found that many of these chemicals remain biologically active even in trace amounts. They can affect plant hormone systems, microbial communities, and nutrient cycling in soil.

CECs may also contribute to antimicrobial resistance, disrupt plant biochemical processes, and alter soil structure. These effects can ultimately influence crop yields and food quality. Persistent substances such as PFAS are especially likely to accumulate in leaf tissues.

The review also points to several underexplored areas. Interactions between multiple contaminants may increase or reduce toxicity, but these combined effects are not well understood. Some exposure routes, such as absorption through leaves (“foliar exposure”), remain poorly studied. In addition, there are uneven global data gaps when it comes to risks for specific crops.
Next steps

The authors call for updated regulations that better reflect real-world conditions, including the effects of chemical mixtures and the role of CECs in antimicrobial resistance. They also recommend long-term field studies, broader geographic representation in research, and the development of safer, degradable alternatives for use in agriculture and industry.

Moores emphasized that the findings align with green chemistry principles, which focus on designing substances that break down into harmless byproducts rather than persisting in the environment.

“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 afterlife,” she said.

Reference: “Contaminants of emerging concern in agricultural soils: Current understanding, overlooked issues, and future priorities” by Laura J. Carter, Evyatar Ben Mordechay, Benny Chefetz, Jay Gan, Hui Li, Audrey Moores

https://doi.org/10.1002/ppp3.70158