Cell type specificity of female lung cancer associated with sulfur dioxide from air pollutants in Taiwan: an ecological study.
BACKGROUND
Many studies have examined the association between air pollutants (including sulfur dioxide [SO2], carbon monoxide [CO], nitrogen dioxide [NO2], nitric oxide [NO], ozone [O3], and particulate matter < 10 μm [PM10]) and lung cancer. However, data from previous studies on pathological cell types were limited, especially for SO2 exposure. We aimed to explore the association between SO2 exposure from outdoor air pollutants and female lung cancer incidence by cell type specificity.


METHODS
We conducted an ecological study and calculated annual average concentration of 6 air pollutants (SO2, CO, NO2, NO, O3, and PM10) using data from Taiwan Environmental Protection Administration air quality monitoring stations. The Poisson regression models were used to evaluate the association between SO2 and age-standardized incidence rate of female lung cancer by two major pathological types (adenocarcinoma [AC] and squamous cell carcinoma [SCC]). In order to understand whether there is a dose-response relationship between SO2 and two major pathological types, we analyzed 4 levels of exposure based on quartiles of concentration of SO2.


RESULTS
The Poisson regression results showed that with the first quartile of SO2 concentration as the baseline, the relative risks for AC/SCC type cancer among females were 1.20 (95% confidence interval [CI], 1.04-1.37)/1.39 (95% CI, 0.96-2.01) for the second, 1.22 (95% CI, 1.04-1.43)/1.58 (95% CI, 1.06-2.37) for the third, and 1.27 (95% CI, 1.06-1.52)/1.80 (95% CI, 1.15-2.84) for the fourth quartile of SO2 concentration. The tests for trend were statistically significant for both AC and SCC at P = 0.0272 and 0.0145, respectively.


CONCLUSIONS
The current study suggests that SO2 exposure as an air pollutant may increase female lung cancer incidence and the associations with female lung cancer is much stronger for SCC than for AC. The findings of this study warrant further investigation on the role of SO2 in the etiology of SCC.
Taipei Physical Education College, Taipei City 11153, Taiwan, R.O.C.
Ching-Yu
CY
Tseng
Yi-Chia
YC
Huang
Shih-Yung
SY
Su
Jing-Yang
JY
Huang
Cheng-Hsiu
CH
Lai
Chia-Chi
CC
Lung
Chien-Chang
CC
Ho
Yung-Po
YP
Liaw
D000230:Adenocarcinoma / Q000139:chemically induced; D000077192:Adenocarcinoma of Lung; D000393:Air Pollutants / Q000009:adverse effects*; D016001:Confidence Intervals; D004305:Dose-Response Relationship, Drug; D004781:Environmental Exposure / Q000032:analysis; D004784:Environmental Monitoring; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000139:chemically induced* / Q000473:pathology*; D018307:Neoplasms, Squamous Cell / Q000139:chemically induced; D016012:Poisson Distribution; D013458:Sulfur Dioxide / Q000506:poisoning*; D013624:Taiwan
D000393:Air Pollutants; D013458:Sulfur Dioxide