Today, our group released findings from an analysis of seasonal construction workers and ambient PM2.5 concentrations in Washington State over the last decade (Analysis conducted by Chris Zuidema, pre-print paper, currently in peer-review).
The analysis estimates the potential impact of wildfire smoke on exposures to construction workers — a workforce of approximately 200,000 workers in 2020 in Washington. Seasonal trends were observed in the employment data, with more construction workers employed during what have been historically high PM2.5 seasons of the year (late summer-early fall).
Considering the new Washington State emergency rule to protect outdoor workers from wildfire smoke, which specifies that at NowCast PM2.5 levels greater than 55.5 µg/m3 (AQI = 101) employers provide N95 or KN95 respirators for voluntary use by workers, we estimate that an average multiple days throughout the year in different parts of the state would potential exceed the threshold, and thus require an estimated 1.35 million respirators be provided each year to construction workers.
While the analysis was focused on the recent Washington State emergency rule thresholds, the analysis also considered the California rule, and discusses the proposed Oregon rule.