Researchers from Nanjing University reported in Eco-Environment & Health on January 19, 2026, that not all microplastics act the same way once they enter farm soil.
In pak choi, the researchers saw PFAS, often called "forever chemicals," rise in the plant under exposure to one widely used plastic, whereas tire-wear particles were associated with reduced uptake.
Here's what to know
Newswise said the work came from researchers at Nanjing University's State Key Laboratory of Water Pollution Control and Green Resource Recycling in the School of the Environment. They examined pak choi exposed to 10 PFAS compounds alongside three microplastic types — PVC, PLA, and TWP — and the paper appeared in Eco-Environment & Health on January 19, 2026.
Among the tested materials, PVC produced the clearest increase. Total PFAS levels in pak choi shoots were 1.31- to 1.70-fold higher at every dose studied, including 0.01%, which the researchers said matches the upper end of concentrations reported in farmland soils.
Tire wear particles showed the opposite pattern. Shoot accumulation of PFAS fell by 37.4% to 54.1%, which the report linked partly to stronger PFAS adsorption and partly to reduced growth and transpiration. At the top dose, TWP cut transpiration to 73% of the control.
When soil contains PFAS, those chemicals can enter edible crops and become a source of dietary exposure.
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Taken together, the results suggest that "microplastics" is too broad to function as a single risk label, because different polymers can alter the movement of contaminants through food systems in different ways.
More background
PFAS are long-lasting synthetic chemicals valued in many industrial and consumer products for their resistance to water and oil. Microplastics reach farmland through sources including plastic mulching, wastewater irrigation, sewage sludge, atmospheric deposition, and tire wear.
The study suggests that PVC may promote the movement of PFAS into edible plant tissue by altering internal water transport, including processes linked to aquaporin-related genes.
PLA, often presented as a biodegradable substitute, showed little overall effect on PFAS accumulation.
Even so, researchers found that PLA still triggered growth and metabolic stress, with its various influences on PFAS uptake largely offsetting one another.
That points to a broader food-safety issue in which the mix of contaminants present may matter as much as any single pollutant on its own.
What can be done?
These findings argue for more targeted soil monitoring, particularly on farmland where PFAS contamination and plastic residues are both present.
Growers and land managers may also need to look more closely at both plastic inputs and field locations. Tire wear particles can accumulate in roadside and industrial soils, while PVC residues may increase the likelihood that PFAS will reach edible crops.
The researchers said future work should examine additional crops, mixed-plastic pollution, and field conditions outside the lab. Follow-up like that could support stronger strategies for keeping both PFAS and microplastics out of the food chain.
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