Disposable gloves can cause false microplastic counts ^{CEFR B2}

Researchers at the University of Michigan warn that common disposable gloves may cause an overestimate of microplastics in environmental samples. Madeline Clough and Anne McNeil found that glove makers coat nitrile and latex gloves with stearates to ease removal from molds, and those coatings can transfer to filters, slides and other collection surfaces used for air, water and other samples.

The project began when Clough, studying microplastics in Michigan’s atmosphere, worked with collaborators to collect air samples on metal substrates and identify particles with light-based spectroscopy. While preparing substrates with nitrile gloves, the team observed particle counts many thousands of times higher than expected and ultimately traced the excess to glove residues.

The researchers tested seven kinds of gloves, mimicking typical contact with sample surfaces, and found an average of about 2,000 false positives per millimeter squared area. Cleanroom gloves released the fewest particles, likely because they lack stearate coatings for ultrapure uses. Scanning electron microscopy showed stearates are visually indistinguishable from polyethylene. Working with Eduardo Ochoa Rivera and Ambuj Tewari, the team identified analytical approaches to separate true microplastics from glove-derived false positives and to recover affected datasets. The work appears in RSC Analytical Methods and was supported by a UM research grant.