Association between Ambient Air Pollution and Emergency Room Visits for Pediatric Respiratory Diseases: The Impact of COVID-19 Pandemic.

The level and composition of air pollution have changed during the coronavirus disease 2019 (COVID-19) pandemic. However, the association between air pollution and pediatric respiratory disease emergency department (ED) visits during the COVID-19 pandemic remains unclear. The study was retrospectively conducted between 2017 and 2020 in Kaohsiung, Taiwan, from 1 January 2020 to 1 May 2020, defined as the period of the COVID-19 pandemic, and 1 January 2017 to 31 May 2019, defined as the pre-COVID-19 pandemic period. We enrolled patients under 17 years old who visited the ED in a medical center and were diagnosed with respiratory diseases such as pneumonia, asthma, bronchitis, and acute pharyngitis. Measurements of particulate matter (PM) with aerodynamic diameters of <10 μm (PM 10 ) and < 2.5 μm (PM 2.5 ), nitrogen dioxide (NO 2 ), and Ozone (O 3 ) were collected. During the COVID-19 pandemic, an increase in the interquartile range of PM 2.5 , PM 10 , and NO 2 levels was associated with increases of 72.5% (95% confidence interval [CI], 50.5-97.7%), 98.0% (95% CI, 70.7-129.6%), and 54.7% (95% CI, 38.7-72.6%), respectively, in the risk of pediatric respiratory disease ED visits on lag 1, which were greater than those in the pre-COVID-19 pandemic period. After adjusting for temperature and humidity, the risk of pediatric respiratory diseases after exposure to PM 2.5 (inter p = 0.001) and PM 10 (inter p < 0.001) was higher during the COVID-19 pandemic. PM 2.5 , PM 10 , and NO 2 may play important roles in pediatric respiratory events in Kaohsiung, Taiwan. Compared with the pre-COVID-19 pandemic period, the levels of PM 2.5 and PM 10 were lower; however, the levels were related to a greater increase in ED during the COVID-19 pandemic.