Estimation of microplastic exposure via the composite sampling of drinking water, respirable air, and cooked food from Mumbai, India

Despite the established presence of microplastics in consumable products and inhalable air and the associated health hazards, the actual extent of human exposure to microplastics is currently unknown. We estimated exposure to microplastics through 24-h composite sampling of drinking water, cooked food, and respirable air. Daily average exposures of 382 ± 205, 594 ± 269, and 1036 ± 493 particles per person were observed through drinking water, air, and food, respectively. Our estimates suggest an average daily exposure of 2012 ± 598 microplastic particles per person via these dominant routes. Considering the variety of common consumer plastics, the plastic intake was calculated to be 122.25 ± 177.38 to 202.80 ± 294.25 mg per person per day. Food ingestion was observed to be the major pathway, with fragments as the dominant particle type, followed by fibers and spherical beads. The major polymers identified in the food samples were polyethylene terephthalate, polystyrene, polynorbornene, nylon, polychloroprene, and copolymer polyacrylamide. These results provide a realistic estimate of urban exposure to microplastics and may be helpful in their risk characterization.