Background:There is insufficient convincing data addressing the public concerns, as to whether exposure of ambient fine particulate matter (PM2.5) increases the risk of cancer or cancer related death other than lung cancer.
Aim:To investigate the association between PM2.5 concentrations and incidence and mortality rates of cancer as a whole entity.
Methods:County-level PM2.5 concentrations from 2001 to 2010 were downloaded from the US EPA Air Quality Statistics Report. Annual PM2.5 data includes the 98th percentile (%ile) of the daily average measurements and the weighted annual mean (Wtd Mean).County-level data of cancer profiles for US males and females respectively were obtained from the State Cancer Profiles website, including age-standardized annual incidence rates and annual mortality rates for all cancer sites, all races, including Hispanics, from 2006 to 2010. Association between PM2.5 concentrations and incidence and mortality rates of female breast cancer was also studied. Linear regression analysis was performed to estimate correlations.
Results:Data indicated either average PM2.5 Wtd Means or average annual PM2.5 98th %iles might be associated to increased incidence and mortality rates of cancer of all sites. In female breast cancer, the unadjusted slope for the linear trend between average annual PM2.5 98th %iles in 2001-2005 and cancer incidence in 2006-2010 was 0.17 (95% Confidence Interval (CI) 0.05, 0.28, p= 0.005) per 1 μg/m3 PM2.5, and that between average PM2.5 Wtd Means in 2001-2005 and cancer incidence in 2006-2010 was 0.35 (95% CI 0.01, 0.69, p= 0.042) per 1 μg/m3 PM2.5.
Conclusions:Not only long-term exposure, but also short peaks of exposure to ambient PM2.5 were associated with increased incidence and mortality rates of cancer as a whole entity, both in US males and females. Exposure to ambient PM2.5 pollution might contribute to increased incidence of US female breast cancer in a short latency period of five years.