Free Webinar - The pandemic’s impact on outdoor and indoor air quality
Date: Aug 23rd, 2021
Time: 5:30 - 6:30 PM EST
Speaker: Lea Hildebrandt Ruiz, Assistant Professor, The University of Texas at Austin
Worldwide, air pollution in indoor and outdoor environments results in approximately 8 million human deaths every year. Reducing air pollution requires a detailed understanding of its sources and atmospheric fate. Restrictions in cities around the world aimed to control the COVID-19 pandemic have provided a novel opportunity to study how changes in human activities and their associated emissions affect atmospheric chemistry and air quality. We assessed impacts of the 2020 COVID-19 lockdown on ambient air quality in Delhi, India. The primary pollutants NOx, CO and BC were most reduced, primarily due to lower transportation emissions. Concentrations of submicron particulate matter (PM1) changed only moderately compared to prior years. The lockdown restrictions led to rather small perturbations in the primary fraction ofPM1, with secondary aerosol (formed from photochemical production) continuing to dominate. Overall, our results demonstrate the impact of secondary and primary pollution on Delhi’s air quality and show that large changes in emissions within Delhi alone are insufficient to bring about needed improvements in air quality.
While lockdown restrictions have decreased emissions, widespread disinfection to curb the spread ofCOVID-19 has increased emissions of disinfectants and their byproducts, increasing human exposure to these compounds, especially in indoor environments. We simulated a classroom and measured exposure to disinfectants and disinfection byproducts. Masks decrease inhalation exposure to some disinfection byproducts and increase exposure to others via adsorption of vapors to the mask. In addition, adsorbed chemicals, mask materials and water vapor (from exhalation) react to produce additional chemical products which are potentially more harmful than the primary vapors. Results from this work can be used to evaluate which disinfectants to use and which masks to wear, and how often to change them, during and after disinfection.