Association between long-term exposure to a mixture of ambient air pollutants and the incidences of bladder and kidney cancers.

BACKGROUND

Evidence regarding associations between air pollution and urinary system cancers, including bladder cancer (BC) and kidney cancer (KC), remains limited and inconsistent. This study assessed the impact of long-term exposure to air pollutant mixtures on BC and KC incidence.

MATERIALS AND

METHODS

Using data from the Korean National Health Information Database (2011-2021) and air pollution estimates (2007-2019), we conducted a nested case-control study involving 3788 BC cases with 15,152 matched controls and 4084 KC cases with 16,336 matched controls. Long-term exposure to PM10, PM2.5, NO2, SO2, and CO was estimated as 5- and 10-year averages with 1- or 2-year lag periods before cancer diagnosis. Quantile g-computation models were used to evaluate mixture effects, adjusting for age, sex, BMI, smoking status, alcohol consumption, and socioeconomic status.

RESULTS

Exposure to air pollutant mixtures was significantly associated with increased BC risk across all exposure scenarios, with odds ratios (ORs) ranging from 1.58 to 1.70 (all p < 0.05). For KC, significant associations were also consistently observed, with ORs ranging from 1.17 to 1.23 (all p < 0.05). PM10, PM2.5, and SO2 consistently demonstrated positive contributions to both cancers, whereas NO2 and CO showed inverse associations across all exposure conditions.

CONCLUSION

Long-term exposure to mixtures of air pollutants was significantly associated with increased risks of BC and KC, with consistent positive contributions identified for PM10, PM2.5, and SO2. These findings highlight specific pollutants of concern and emphasize the need for targeted public health strategies to mitigate air pollution exposure and potentially reduce urinary cancer incidence.