Pittsburgh Air Pollution Changes During the COVID-19 Lockdown

Area of Science:

• Environmental Science
• Atmospheric Chemistry
• Public Health

Background:

• Global COVID-19 lockdowns led to travel restrictions, impacting air quality.
• Previous studies indicated improved air quality due to reduced travel.
• Pittsburgh, with its industrial history, faces challenges with particulate matter (PM2.5).

Purpose of the Study:

• To analyze source-specific air pollution changes during the COVID-19 lockdown in Pittsburgh.
• To compare air quality changes over multiple years, controlling for precipitation.
• To investigate the impact of lockdowns on nitrogen dioxide (NO2) and particulate matter (PM2.5, PM10).

Main Methods:

• Utilized data from the Allegheny County Health Department air quality monitors.
• Employed generalized linear models with a gamma distribution and log link.
• Analyzed pollution changes, specifically NO2, PM2.5, and PM10, during the COVID-19 lockdown period.

Main Results:

• Nitrogen dioxide (NO2) significantly decreased at all monitoring sites.
• PM10 pollution also significantly reduced at most monitoring sites.
• PM2.5 reductions were observed at only half the sites, with the largest decrease near an industrial source, likely due to reduced industrial activity.

Conclusions:

• Industrial sources are significant contributors to Pittsburgh's particulate matter pollution.
• Vehicular traffic reduction had a less pronounced effect on PM2.5 compared to industrial emissions.
• Future air pollution control strategies should prioritize industrial emission reductions in Pittsburgh.