Impact of climate and ambient air pollution on the epidemic growth during COVID-19 outbreak in Japan

• Published in: Environmental research Vol. 190; p. 110042
• Main Authors: Azuma, Kenichi, Kagi, Naoki, Kim, Hoon, Hayashi, Motoya
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Inc 01.11.2020
• Subjects: Activities of Daily Living; Air Pollution - analysis; Betacoronavirus; Climate; Coronavirus; Coronavirus Infections - transmission; COVID-19; Disease Outbreaks; Epidemic growth; Female; Humans; Japan; Longitudinal Studies; Male; Pandemics; Particulate matter; Pneumonia, Viral - transmission; SARS-CoV-2; Sunshine; Temperature; Japan; COVID-19; Temperature; Sunshine; Particulate matter; Epidemic growth
• ISSN: 0013-9351; 1096-0953
• DOI: 10.1016/j.envres.2020.110042

Coronavirus disease 2019 (COVID-19) rapidly spread worldwide in the first quarter of 2020 and resulted in a global crisis. Investigation of the potential association of the spread of the COVID-19 infection with climate or ambient air pollution could lead to the development of preventive strategies for disease control. To examine this association, we conducted a longitudinal cohort study of 28 geographical areas of Japan with documented outbreaks of COVID-19. We analyzed data obtained from March 13 to April 6, 2020, before the Japanese government declared a state of emergency. The results revealed that the epidemic growth of COVID-19 was significantly associated with increase in daily temperature or sunshine hours. This suggests that an increase in person-to-person contact due to increased outing activities on a warm and/or sunny day might promote the transmission of COVID-19. Our results also suggested that short-term exposure to suspended particles might influence respiratory infections caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Further research by well-designed or well-controlled study models is required to ascertain this effect. Our findings suggest that weather has an indirect role in the transmission of COVID-19 and that daily adequate preventive behavior decreases the transmission. [Display omitted] •Association between COVID-19 infection and climate or air pollution was examined.•Epidemic growth of COVID-19 was associated with increased temperature or sunshine hours.•Increase of contact among persons on a warm or sunny day may promote infection.•Short-term exposure to suspended particles may influence the respiratory infection.•Correct knowledge and adequate preventive behavior decrease its transmission.