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There Is an Alarming Amount of Microplastics in Farm Soil—and Our Food Supply

More microplastics are contaminating agricultural lands than oceans, impacting plant development and ending up in produce and people.

Mary Beth Kirkham hadn’t studied microplastics when she was invited to co-edit a new book about microplastics in the environment—but something stood out to her about the existing research.

“I had read in the literature that . . . cadmium and other toxic trace elements [are] increased when we have these particulate plastics in the soil. So, that was of concern to me,” said Kirkham, a plant physiologist and distinguished professor of agronomy at Kansas State University.

Kirkham’s expertise is in water and plant relations and heavy metal uptake, so she decided to conduct her own research in which she cultivated wheat plants exposed to microplastics, cadmium, and both microplastics and cadmium. Then she compared these plants to those grown without either additive. She chose cadmium because it’s poisonous, carcinogenic, and ubiquitous in the environment due to human activity—it’s shed from batteries and car tires, and is naturally found in the phosphate rock used to make agricultural fertilizers.

“Cadmium is everywhere,” said Kirkham.