According to the International Agency for Research on Cancer (IARC), airborne fine particulate matter (PM2.5), which is categorized as a Group I carcinogen, was found to lead to predominantly lung as well as other cancer types in humans. Hepatocellular carcinoma (HCC) is endemic in Taiwan where it is the second and fourth foremost cause of cancer deaths in men and women, respectively. Taiwan's mortality rates for liver cancer vary considerably from one region to another, suggesting that the environment may exert some influence on deaths attributed to liver cancer. The aim of this investigation was to perform an ecologic study to examine the possible link between ambient PM2.5 levels and risk of liver cancer in 66 in Taiwan municipalities. To undertake this investigation, annual PM2.5 levels and age-standardized liver cancer mortality rates were calculated for male and female residents of these areas from 2010 to 2019. Data were tested using weighted-multiple regression analyses to compute adjusted risk ratio (RR) controlling for urbanization level and physician density. Annual PM2.5 levels of each municipality were divided into tertiles. The adjusted RRs for males residing in those areas with intermediate tertile levels (21.85 to 28.21 ug/m3) and the highest tertiles levels (28.22-31.23 ug/m3) of PM2.5 were 1.29 (95% CI = 1.25-1.46) and 1.41 (95% CI = 1.36-1.46), respectively. Women in these locations shared a similar risk, 1.32 (1.25-1.4) and 1.41 (1.34-1.49), respectively. Evidence indicated that PM2.5 increased risk of mortality rates attributed to liver cancer in both men and women in Taiwan.
Keywords: air pollution; exposure; fine particle; liver cancer.