The need for multifaceted approaches when dealing with the differing impacts of natural disasters and anthropocentric events on air quality

ABSTRACT

Air pollution associated health issues are increasing globally. This is due to both anthropogenic sources, such as traffic, and natural sources, such as bushfires. Natural disasters, such as bushfires, impact air quality by releasing large concentrations of pollutants affecting respiratory health. However, another recent global event has also had severe impacts on the environment and health, the global COVID-19 pandemic. Global pandemics, such as COVID-19, can also influence air quality by altering human activity, resulting in its own associated health impacts. This study aimed to investigate the impact of a natural disaster and global pandemic on outdoor ambient air pollution by quantifying and comparing the spatial distribution of two air pollutants, nitrogen dioxide (NO2) and particulate matter (PM10), during the different periods across the Greater Sydney region, Australia, while correcting for anthropogenic sources and meteorological influences such as temperature and rain. COVID-19 and bushfire affected periods were compared to a control period when both of these influences were absent. We found that NO2 was significantly higher during the COVID-19 pandemic than during the control period and the recent 2019 bushfires. Conversely, PM10 was significantly lower during the COVID-19 pandemic than the bushfire and control periods. The spatial distribution of both pollutants and influencers also varied across the study site. These results suggest that both events markedly impacted air quality, although they impacted the air pollutants differently. These findings further demonstrate a greater need to understand the impact of natural disasters and anthropocentric events on air pollution as multifaceted, spatially relevant policies are required to address these events, particularly if they increase in frequency or severity in the future.