This four-year study recorded the lowest airborne microplastics concentration in the atmosphere in the Northeastern United States in the initial months of the COVID-19 economic lockdown

In April 2020, 42 states and territories in the United States issued mandatory stay-at-home orders. According to the United Nations, by April 2020, lockdown measures had affected almost 2.7 billion workers, representing ~80% of the world’s workforce.

This unprecedented sharp slowing of the global economy unlocked a singular opportunity to quantify the impact that economic activity has on the concentration of microplastics circulating in the earth’s lower atmosphere.

This research began collecting precipitation samples to measure micro-fiber and micro-particle contamination in May 2020 to assess whether the COVID-19 economic lockdowns had reduced the concentration of airborne microplastics. Over the next 1,366 days—with April 1, 2020 representing “Day 0,” when ~50% of the world’s population was under lockdown—this research collected 513 micro-fibers and 11,018 micro-particles from 65 rain and snow samples from a remote field in rural Pennsylvania.

Through December 2023, micro-fibers and micro-particles entrapped by the freshly fallen rain and snow were filtered, photographed, and analyzed for physical characteristics, utilizing specialized FTIR microscopic spectroscopy to identify the composition of micro-fibers collected over a four-year period.

Findings confirmed the synthetic and processed composition of micro-fibers and that they increased over time, suggesting that concentrations of microplastics carried in the lower atmosphere are correlated to levels of economic activity.

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Looking back 3.6 years (1,366 days) after the COVID-19 lockdown, airborne micro-fiber count was lowest the first 8 months, then rose as economic activity resumed

FTIR analysis of micro-fiber composition revealed increasing synthetic and processed material over time