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Microplastic contamination in the San Francisco Bay, California, USA

Marine Pollution Bulletin 2016 418 citations ? Citation count from OpenAlex, updated daily. May differ slightly from the publisher's own count.
Rebecca Sutton, Sherri A. Mason, Shavonne K. Stanek, Ellen Willis‐Norton, Ian Wren, Carolynn Box

Summary

Researchers measured microplastic abundance across nine sites in San Francisco Bay and in effluent from eight wastewater treatment plants, finding average surface water concentrations of 700,000 particles per km² — higher than other North American urban waterbodies — and noting that tertiary filtration did not meaningfully reduce microplastic discharge compared to secondary treatment.

Study Type Environmental

Despite widespread detection of microplastic pollution in marine environments, data describing microplastic abundance in urban estuaries and microplastic discharge via treated municipal wastewater are limited. This study presents information on abundance, distribution, and composition of microplastic at nine sites in San Francisco Bay, California, USA. Also presented are characterizations of microplastic in final effluent from eight wastewater treatment plants, employing varying treatment technologies, that discharge to the Bay. With an average microplastic abundance of 700,000particles/km(2), Bay surface water appears to have higher microplastic levels than other urban waterbodies sampled in North America. Moreover, treated wastewater from facilities that discharge into the Bay contains considerable microplastic contamination. Facilities employing tertiary filtration did not show lower levels of contamination than those using secondary treatment. As textile-derived fibers were more abundant in wastewater, higher levels of fragments in surface water suggest additional pathways of microplastic pollution, such as stormwater runoff.

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