Hebrew University Study Finds Tire Particles Pollute Crops and Enter Food Chain

A new study by researchers from the Hebrew University of Jerusalem reveals that microscopic particles released from worn vehicle tires contaminate nearby agricultural fields and ultimately enter the human food chain. Each year, about 1.5 billion tires are produced worldwide, and as they wear down during driving, they emit tiny particles that carry various organic pollutants. These pollutants can be absorbed by crops such as lettuce and alfalfa, posing a potential risk to food safety.

The research, published in Environmental Research, was conducted by Chao Gao, Prof. Benny Chefetz, and Dr. Evyatar Ben Mordechai. It shows that tire wear particles (TWPs) act as "pollutant capsules," gradually releasing harmful chemicals into the soil over extended periods. One key pollutant, Diphenylguanidine (DPG), was found in relatively high concentrations in plant leaves and is known to be toxic, having been detected in human urine and blood samples in other countries.

The study involved collecting tire particles from garages across Israel and testing their chemical release and absorption in crops. It found that pollutants enter fields not only directly from road dust but also via irrigation with treated wastewater and the application of compost derived from sewage sludge. Israeli produce irrigated with recycled water showed the highest levels of certain chemicals, such as benzothiazole, compared to samples from Switzerland, Italy, and Spain.

Although the daily intake of these chemicals through vegetables is currently low, the researchers warn that exposure is continuous and unmonitored. They call for comprehensive environmental surveys near roads, the establishment of buffer zones prohibiting food crop cultivation close to highways, and improved wastewater and runoff management to reduce contamination. The study emphasizes the need for updated regulations and a holistic approach recognizing the interconnected health of the environment and humans.

This research highlights an emerging environmental and public health concern linked to modern transportation and agricultural practices in Israel and beyond.