Review Human and Animal Health How Have Particulate Matter, Weather Conditions and Smoking Contributed to the Transmission and Aggravation of the COVID-19 Pandemic?

One of the most important issues, according to the World Health Organization, to be addressed during the COVID-19 pandemic is understanding the risk factors for the severity of the disease. Some studies show a possible association of SARS-CoV-2 with risk factors such as particulate matter and some weather conditions, in addition to behavioral factors such as smoking. The present review aimed to evaluate the correlation between COVID-19 and these potential risk factors. The Web of Science database searched for eligible studies covering experimental and epidemiological studies from March 2020 to March 2022. The recognized risk groups for an unfavorable evolution are the elderly, those with chronic diseases (such as diabetes, hypertension, and pulmonary diseases), and those who use immunobiological or chemotherapy drugs. But some environmental factors may come to transmit the severity of COVID-19 cases. Lifestyle may be responsible for the variability in the severity of COVID-19, with smoking being one of the main factors, yet environmental factors such as particulate matter levels, humidity, and temperature have been shown to affect the transmissibility of SARS-CoV-2.