Recently, a study published by the Harvard Chen Zengxi School of Public Health in the international academic journal "Science Advances" showed that short-term or long-term exposure to PM2.5 is associated with an increase in confirmed and death cases of new crowns.
In 2020, wildfires swept the western United States. In order to verify the impact of air pollution on the new crown epidemic, the researchers established a statistical model to quantify the extent to which PM2.5 from wildfires has caused damage in California, Oregon, and Washington (the three states most affected by wildfires) The number of additional confirmed and fatal cases of the new crown. They studied PM2.5 air concentration data, satellite data, and the correlation between the number of new crown cases and deaths in 92 counties (95% of the population of the three states). In addition, factors such as weather, population size, social distance, and social patterns of mass gatherings are also taken into consideration.
The study found that during the worst wildfires in the United States, the daily average level of PM2.5 was significantly higher than that on non-wildfire days, with an average of 31.2 micrograms per cubic meter of air, while the daily average level of PM2.5 on non-wildfire days was 6.4 micrograms. Wildfires can increase the impact of exposure to PM2.5 on COVID-19 cases and deaths, up to 4 weeks after exposure. On average, in the 28 days after wildfires, PM2.5 increased by 10 micrograms per day in all counties, confirmed cases of new crowns increased by 11.7%, and deaths from new crowns increased by 8.4%. Wildfires have the greatest impact on confirmed cases of new crowns in California's Sonoma County and Washington State's Whitman County, with cases in the two counties increasing by 65.3% and 71.6% respectively; wildfires have the greatest impact on the number of new crown deaths in California and San Francisco. Bernardino increased by 52.8% and 65.9% respectively.
The results of the study prove that the air pollution caused by wildfires in the western United States in 2020 is related to the increase in the number of new crown cases and deaths in the three western states at the same time.
