Impact of air pollution on breast cancer incidence and mortality: a nationwide analysis in South Korea

Abstract

Breast cancer is one of the major female health problems worldwide. Although there is growing evidence indicating that air pollution increases the risk of breast cancer, there is still inconsistency among previous studies. Unlike the previous studies those had case-control or cohort study designs, we performed a nationwide, whole-population census study. In all 252 administrative districts in South Korea, the associations between ambient no 2 and particulate matter 10 (PM 10) concentration, and age-adjusted breast cancer mortality rate in females (from 2005 to 2016, N mortality = 23,565), and incidence rate (from 2004 to 2013, N incidence = 133,373) were investigated via multivariable beta regression. population density, altitude, rate of higher education, smoking rate, obesity rate, parity, unemployment rate, breastfeeding rate, oral contraceptive usage rate, and Gross Regional Domestic product per capita were considered as potential confounders. Ambient air pollutant concentrations were positively and significantly associated with the breast cancer incidence rate: per 100 ppb CO increase, odds Ratio oR = 1.08 (95% Confidence Interval CI = 1.06-1.10), per 10 ppb NO 2 , oR = 1.14 (95% CI = 1.12-1.16), per 1 ppb SO 2 , oR = 1.04 (95% CI = 1.02-1.05), per 10 µg/m 3 PM 10 , oR = 1.13 (95% ci = 1.09-1.17). However, no significant association between the air pollutants and the breast cancer mortality rate was observed except for PM 10 : per 10 µg/m 3 PM 10 , oR = 1.05 (95% CI = 1.01-1.09). Breast cancer is the most frequently diagnosed cancer among women worldwide 1 , and is rapidly increasing in industrialized countries and urban areas. In South Korea, breast cancer is the second most common after thyroid cancer and has annually increased by 6.1% from 1999 to 2014 2,3. Increased exposure to environmental female hormones is considered to affect the rise of breast cancer incidence. In addition, hormone-dependent cancer is increasing in industrialized countries 1,4. There is growing evidence indicating that air pollution is a risk factor for breast cancer. Nitrogen oxides (NO 2 and NO x) 5-9 , fine particulate matters (PM 10 and PM 2.5) 10,11 , and polycyclic aromatic hydrocarbons (PAHs) 12,13 are reported to associate with breast cancer incidence. The physiological mechanisms by which air pollutants affect breast cancer are largely explained in two ways. First, air pollutants may directly cause genetic mutations, as they are carcinogenic 14,15. Second, air pollutants may affect breast cancer incidence by increasing breast density, which is known to be a risk factor. Yaghjyan et al. reported an association between exposure to PM 2.5 , O 3 , and mammographic breast density 16. Female hormones affect breast density, and some air pollutants are known to exhibit endocrine-disrupting properties, including xenoestrogens 17. However, in the Danish Diet, Cancer and Health cohort (1993-1997) study, little evidence of association between traffic-related air pollution exposure and breast density was found 18. Hung et al. reported ...

Association between long-term exposure to air pollutants and cardiopulmonary mortality rates in South Korea

“…For example, in both urban and rural areas, NO 2 concentrations may be harmful for respiratory health and there may have been an increase medical service usage such as emergency department visits or hospitalization related to CLRD, but accessibility or the quality of medical service may be different in urban and rural areas. In our previous study on the association between air pollution and the incidence and mortality rates of breast cancer, air pollution was positively associated with the incidence rates but not with the mortality rates [13]. This conjecture could be resolved with data on the incidence rates of CLRD per district, which is not presently available.…”

“…For each air pollutant and district, the average air pollutant concentrations throughout the study period (2001-2018) was computed. The above mentioned method is largely similar to that used in our previous study [13].…”

Association between long-term exposure to air pollutants and cardiopulmonary mortality rates in South Korea

“…For example, in both urban and rural areas, NO 2 concentrations may be harmful for respiratory health and there may have been an increase medical service usage such as emergency department visits or hospitalization related to CLRD, but accessibility or the quality of medical service may be different in urban and rural areas. In our previous study on the association between air pollution and the incidence and mortality rates of breast cancer, air pollution was positively associated with the incidence rates but not with the mortality rates [14]. This conjecture could be resolved with data on the incidence rates of CLRD per district, which is not presently available.…”

“…For each air pollutant and district, the average air pollutant concentrations throughout the study period (2001-2018) was computed. The above mentioned method is largely similar to that used in our previous study [14].…”

Spatio-temporal Mapping of Breast and Prostate Cancer in South Iran During 2014-2017

“…Environmental risk factors such as air pollution (30)(31)(32) and heavy metals (33, 34) could be linked to the geographic outcome disparities in breast and\or prostate cancer incidence. We found high-risk areas of breast and prostate cancer in the Northwest of the province during 2014-2017.…”