Estimating human microplastic consumption

If you get your recommended daily hydration exclusively from bottled water, you’re consuming an additional 90,000 particles of microplastic per year. That’s one of the alarming findings of the first study to take a comprehensive look at available data on human microplastic consumption (Environ. Sci. Technol. 2019, DOI: 10.1021/acs.est.9b01517). Marine ecologist Kieran D. Cox, part of a team led by Sarah E. Dudas at the University of Victoria, and collaborators culled all the high-quality data they could find about microplastic levels in air, water and other beverages, and foods. Then, extrapolating from US-recommended daily allowances and consumption habits, they estimated how much microplastic Americans consume each year. The study is incomplete: data are available for salt, honey, bottled water, fish, and other products, but not for foods that make up 85% of the calories that Americans consume, including meat, grains, and vegetables. From existing data, the researchers estimate that people ingest at least 39,000 to 52,000 microplastic particles per year. Because the data are incomplete, the actual consumption of these plastics—which can be sources of toxic compounds and endocrine disruptors—is likely far higher, Cox says. “If you have the privilege to choose tap water and buy less single-use plastic, you can drastically change your exposure,” he says.