Airborne fine particulate matter (PM2.5) has been classified as a Group I carcinogen leading to lung cancer in humans by the International Agency for Research on Cancer (IARC). In Taiwan, where there is a growing incidence of this disease, lung cancer is currently the leading cause of cancer-associated deaths in women and second leading cause of deaths in men. Because tobacco use is rare in Taiwan, especially amongst women, the high incidence of this type of cancer was suggested to be attributed to the other external contaminants, including airborne PM2 pollution. In this ecologic study, a possible association between ambient air PM2.5 exposure and likelihood of death attributed to lung cancer was examined in Taiwan in 66 municipalities. Annual PM2.5 levels and age-standardized lung cancer mortality rates for male and female residents were calculated for years 2010 to 2019. Weighted-multiple regression was applied to analyze our data, adjusting for level of urbanization and physician density. For males, the adjusted risk ratios (RRs) for lung cancer mortality were 1.01 for municipalities with PM2.5 levels 21.85-28.21 ug/m3 and 1.07 for municipalities with 28.22-31.23 ug/m3, compared to those with the lowest PM2.5 levels. For females, these adjusted RRs were 0.99 and 1.06, respectively. Data demonstrated an association between chronic exposure to high levels of PM2.5 and increased likelihood of death attributed to lung cancer for both men and women in Taiwan. Further studies are needed to explore the relationship between PM2.5 air pollution exposure and risk of lung cancer histologic subtype.
Keywords: PM2.5; air pollution; death; lung cancer.