Environmental Health: Outdoor Air Pollution and other cancers

Outdoor air pollution and other cancers

From 1978 to the end of 2003, a follow-up study was conducted on cancer occurrence among bus drivers in three Danish cities. The study involved 2,037 subjects, among whom 70% of men were smokers. The incidence rate (SIR) for all cancers was 1.09 (95% CI, 1.0-1.2), with bladder cancer risk being 1.6 times higher (95% CI, 1.2-2.0) compared to the non-exposed group (1).

 

In the US Cancer Prevention Study II (CPS-II), focusing on ambient air pollution and cancer death, a significant association was found between increased PM2.5 concentration and elevated risk of kidney cancer,  and bladder cancer, excluding lung cancer. Specifically, when PM2.5 concentration increased by 4.4 μg/㎥, bladder cancer risk increased by 1.14 times (95% CI: 1.03-1.27) and bladder cancer risk increased by 1.13 times (95% CI: 1.03-1.23) (2).

 

A study involving 57,589 women primarily residing in Los Angeles, conducted from 1993 to 2010, found a significant association between air pollution and breast cancer incidence. The study adjusted for confounding variables using the Cox proportional hazards model and investigated the relationship between air pollution and breast cancer incidence, stratifying by race and proximity to residence and transportation. The findings indicated that women living less than 500 meters from main roads had an increased risk of breast cancer. Exposure was measured using interpolation techniques such as Kriging and Land Use Regression. Specifically, when the distance between residence and road measured by Kriging was less than 500 meters, the patient group had higher levels of NOx (1.35 times, 95%CI: 1.02-0.79), NO2 (1.44 times, 95%CI: 1.04-0.99), and PM10 (1.29 times, 95%CI: 1.07-0.55), with PM2.5 being 1.85 times higher (95%CI: 1.15-2.99). NOx measured using Land Use Regression (LUR) technique showed 1.21 times increase (95%CI: 1.01-0.45), and NO2 showed 1.26 times increase (95%CI: 1.00-0.59) (3).

 

In the United States, a study followed 47,433 participants with sisters diagnosed with breast cancer for an average of 8.4 years. The study measured air pollution levels (PM2.5, PM10, NO2) around residential areas and found that PM2.5 and NO2 were associated with 1.05 times (95%CI: 0.99, 1.11) and 1.06 times (95%CI: 1.02, 1.11) higher overall risk of breast cancer, respectively. However, no significant association was observed with invasive cancer (4).

In another cohort of 89,247 women enrolled in the Canadian National Breast Screening Study from 1980 to 1985, the association between PM2.5 exposure around residence and breast cancer occurrence was investigated until 2005. Results showed that when PM2.5 increased by 10μg/㎥, the risk increased by 1.26 times before menopause (95%CI: 0.99, 1.61) and 1.01 times after menopause (95%CI: 0.94, 1.10), although not statistically significant (5).

 

■  References

 

(1)     Pedersen, D. U., Durant, J. L., Penman, B. W., Crespi, C. L., Hemond, H. F., Lafleur, A. L., & Cass, G. R. (2004). Human-cell mutagens in respirable airborne particles in the northeastern United States. 1. Mutagenicity of fractionated samples. Environ Sci Technol, 38 (3), 682-689.

(2)     Turner, M. C., Krewski, D., Diver, W. R., Pope, C. A., 3rd, Burnett, R. T., Jerrett, M., . . . Gapstur, S. M. (2017). Ambient Air Pollution and Cancer Mortality in the Cancer Prevention Study II. Environ Health Perspect, 125 (8), 087013-087013.

(3)     Cheng, I., Tseng, C., Wu, J., Yang, J., Conroy, S. M., Shariff-Marco, S., . . . Wu, A. H. (2020). Association between ambient air pollution and breast cancer risk: The multiethnic cohort study. Int J Cancer, 146 (3), 699-711.

(4)     White, A. J., Keller, J. P., Zhao, S., Carroll, R., Kaufman, J. D., & Sandler, D. P. (2019). Air Pollution, Clustering of Particulate Matter Components, and Breast Cancer in the Sister Study: A U.S.-Wide Cohort. Environ Health Perspect, 127 (10), 107002-107002.

(5)    Villeneuve, P. J., Goldberg, M. S., Crouse, D. L., To, T., Weichenthal, S. A., Wall, C., & Miller, A. B. (2018). Residential exposure to fine particulate matter air pollution and incident breast cancer in a cohort of Canadian women.Environ Epidemiol, 2 (3).