COVID-19 Outbreak Related to PM10, PM2.5, Air Temperature and Relative Humidity in Ahvaz, Iran
Yusef Omidi Khaniabadi, Pierre Sicard, Bahram Dehghan, Hassan Mousavi, Saeid Saeidimehr, Mohammad Heidari Farsani, Sadegh Moghimi Monfared, Heidar Maleki, Hojat Moghadam, Pouran Moulaei Birgani
Abstract
In this study, we assessed several points related to the incidence of COVID-19 between March 2020 and March 2021 in the Petroleum Hospital of Ahvaz (Iran) by analyzing COVID-19 data from patients referred to the hospital. We found that 57.5% of infected referrals were male, 61.7% of deaths by COVID-19 occurred in subjects over 65 years of age, and only 2.4% of deaths occurred in younger subjects (> 30 years old). Analysis showed that mean PM 10 and PM 2.5 concentrations were correlated to the incidence of COVID-19 ( r = 0.547, P < 0.05, and r = 0.609, P < 0.05, respectively) and positive chest CT scans ( r = 0.597, P < 0.05, and r = 0.541, P < 0.05 respectively). We observed that a high daily air temperature (30–51 °C) and a high relative humidity (60–97%) led to a significant reduction in the daily incidence of COVID-19. The highest number of positive chest CT scans were obtained in June 2020 and March 2021 for daily air temperature ranging from 38 °C and 49 °C and 11 °C and 15 °C, respectively. A negative correlation was detected between COVID-19 cases and air temperature ( r = − 0.320, P < 0.05) and relative humidity ( r = − 0.384, P < 0.05). In Ahvaz, a daily air temperature of 10–28 °C and relative humidity of 19–40% are suitable for the spread of coronavirus. The highest correlation with the number of COVID-19 cases was found at lag3 ( r = 0.42) and at lag0 with a positive chest CT scan ( r = 0.56). For air temperature and relative humidity, the highest correlations were found at day 0 (lag0). During lockdown (22 March to 21 April 2020), a reduction was observed for PM 10 (29.6%), PM 2.5 (36.9%) and the Air Quality Index (33.3%) when compared to the previous month. During the pandemic period (2020–2021), the annual mean concentrations of PM 10 (27.3%) and PM 2.5 (17.8%) were reduced compared to the 2015–2019 period.