Physicochemical characterization and health risk modeling of atmospheric particulate matter

Abstract

The intention of this investigation is to inspect the variations in air quality and highlight the physicochemical aspect of PM_2.5 and PM₁₀ and its health risk in the most polluted city Lucknow, India during 2019 and 2020. The sampling of both pollutants PM₁₀ and PM_2.5 were conducted 4 times/month for 24 h in four diverse urban areas of Lucknow viz., institutional-(BBAU), residential-(Gomti Nagar), semi-commercial-(Indira Nagar) and commercial cum traffic area-(Hazratganj). The PM₁₀ and PM_2.5 particles were taken on glass microfiber filter paper using Respirable Dust Sampler and Fine Particulate Sampler respectively. The decline in levels of PM_2.5, PM₁₀ and air quality index were found 43%, 42% and 38% μg/m³ respectively in 2020 compared to 2019. The morphological and elemental compositions of PM₁₀ and PM_2.5 pollutants displayed wide disparity during the study period, the key components viz., lead-(spherical), cadmium-(crystalline), biological particles-(capsule/oval), carbon particles-(spherical-porous) and vehicle exhaust-(slight-spherical). The health exposure of PM₁₀ and PM_2.5 has also been computed on AirQ+, long-term exposure to PM₁₀ led to a 38% decline in post-neonatal mortality for all causes in 2020 compared to 2019. Whereas the long-term magnitude of mortality due to all causes from PM_2.5 exposure was 46% lower in 2020 compared to 2019. This sharp reduction in air quality and remarkable improvement in mortality in 2020 compared to 2019 was linked to controlled anthropogenic activities because of the COVID-19 pandemic. These reductions in PMs as well as in all-cause mortality led to significant improvement in air quality in 2020 compared to 2019.