Concentrations and mortality due to short- and long-term exposure to PM2.5 in a megacity of Iran (2014–2019)

The present study aimed to survey the spatial and temporal trends of ambient concentration of PM₂.₅ and to estimate mortality attributed to short- and long-term exposure to PM₂.₅ in Isfahan from March 2014 to March 2019 using the AirQ⁺ software. The hourly concentrations of PM₂.₅ were obtained from the Isfahan Department of Environment and Isfahan Air Quality Monitoring Center. Then, the 24-h mean concentration of PM₂.₅ for each station was calculated using the Excel software. According to the results, the annual mean concentration of PM₂.₅ in 2014–2019 was 29.9–50.9 μg/m³, approximately 3–5 times higher than the WHO guideline (10 μg/m³). The data showed that people of Isfahan in almost 58% to 96% of the days of a year were exposed to PM₂.₅ higher than the WHO daily guideline. The concentrations of PM₂.₅ in cold months such as October, November, December and January were higher than those in the other months. The zoning of the annual concentrations of PM₂.₅ in urban areas showed that the highest PM₂.₅ concentrations were related to the northern, northwestern, southern and central areas of the city. On average, from 2014 to 2019, the number of deaths due to natural mortality, lung cancer (LC), chronic obstructive pulmonary disease (COPD), ischemic heart disease (IHD) and stroke associated with ambient PM₂.₅ were 948, 16, 18, 281 and 60, respectively. The present study estimated that on average, 14.29% of the total mortality, 17.2% of lung cancer (LC), 15.54% of chronic obstructive pulmonary disease (COPD), 17.12% of ischemic heart disease (IHD) and 14.94% of stroke mortalities were related to long-term exposure to ambient PM₂.₅. So provincial managers and politicians must adopt appropriate strategies to control air pollution and reduce the attributable health effects and economic losses.