Reductions of Plastic Microbeads from Personal Care Products in Wastewater Effluents and Lake Waters Following Regulatory Actions

Plastic microbeads were widely used as exfoliants in
personal care
products (PCPs; e.g., hand/body washes) in North America, but restrictions
were imposed on their use in PCPs in the U.S. (2017) and Canada (2018).
We provide the first assessment of whether restrictions are effectively
reducing microbeads entering surface waters. We examined their abundance,
character, and trends in wastewater treatment plant (WWTP) effluents
in Toronto, Canada, from 2016 to 2019, and in adjacent Lake Ontario
surface waters (2015 and 2018), encompassing the period before and
after the bans. Microbeads isolated from PCPs purchased in 2015 provided
a visual morphological key with “irregular” and “spherical”
microbead categories. Median concentrations of irregular microbeads,
composed of polyethylene plastic, declined by up to 86% in WWTP effluents
from 8.4 to 14.3 particles/m3 before to 2.0–2.2
particles/m3 after the bans, while those of spherical microbeads,
predominantly synthetic/polyethylene wax, ranged within 0.5–2.3
particles/m3 and did not differ before and after the bans
since, as nonplastic, they were not regulated. Similarly, amounts
of irregular microbeads declined relative to spherical microbeads
in Lake Ontario, indicating that product changes may be influencing
observations in lake waters. The results suggest that the Canadian
and U.S. restrictions effectively and rapidly reduced plastic microbeads
entering waters via WWTPs.