Microplastics accumulating in UK soils are emerging as a significant threat to the country’s food security, according to a new report by the all-party parliamentary group (APPG) on microplastics. Scientists, MPs, and campaigners collaborating on the report have called for legally binding targets to reduce microplastic pollution, emphasizing the need for a comprehensive approach to address this growing environmental concern.

The report identifies UK agricultural soils as among the most contaminated by microplastics in Europe. A key contributor to this contamination is the repeated application of sewage sludge from water treatment plants used as fertilizer. As the agricultural sector faces increasing challenges from extreme weather conditions, the protection of soil health is becoming ever more critical.

Alberto Costa, MP for South Leicestershire and chair of the APPG, highlighted the urgency of stronger measures, stating that current policies address only a small fraction of microplastic emissions. He urged a preventative strategy focusing on reducing microplastic releases at their source to safeguard both human health and food security.

Microplastics, defined as plastic particles ranging from 1 micrometre to 5 millimetres in size, originate from the breakdown of everyday items including synthetic textiles, packaging, paints, cosmetics, and car tyres. Even smaller particles, called nanoplastics—those under 1 micrometre—are capable of permeating biological membranes, making them potentially more harmful. Prof Cressida Bowyer, director of the Revolution Plastics Institute at the University of Portsmouth and senior author of the report, explained that microplastics are found ubiquitously in the environment, from deep soil layers to high altitudes, and increasingly detected throughout the human body.

Bowyer noted that exposure to microplastics occurs across the entire plastics lifecycle—not only during production and disposal but also throughout everyday use. Common sources include plastic packaging, textiles, and household items such as plastic chopping boards and blankets.

Evidence submitted to the APPG report raises concerns about the impact of microplastics on soil ecosystems. Plastic particles can alter soil structure and water retention, disrupt microbial communities essential for soil fertility, and affect soil fauna. For example, earthworms that ingest microplastics experience physiological changes, which may impair their role in maintaining healthy soil.

The report sets out five key policy recommendations: establishing legally binding targets to reduce microplastic pollution; regulating the largest sources of microplastic emissions; implementing extended producer responsibility measures across the plastics lifecycle; enhancing protections relating to wastewater, sewage sludge, and soil; and creating a coordinated national system to monitor and gather evidence on microplastics.

The Department for Environment, Food and Rural Affairs was contacted for comment but had not responded at the time of publication.