Lung cancer in Chinese women: evidence for an interaction between tobacco smoking and exposure to inhalants in the indoor environment.
BACKGROUND
Epidemiologic data suggest that Chinese women have a high incidence of lung cancer in relation to their smoking prevalence. In addition to active tobacco smoke exposure, other sources of fumes and airborne particles in the indoor environment, such as cooking and burning of incense and mosquito coils, have been considered potential risk factors for lung cancer.


OBJECTIVE
We used a case-control study to explore effects of inhalants from combustion sources common in the domestic environment on lung cancer and their modification by active tobacco smoking.


METHODS
We analyzed 703 primary lung cancer cases and 1,578 controls. Data on demographic background and relevant exposures were obtained by face-to-face interviews in the hospital.


RESULTS
We observed a positive relationship with daily exposure to incense or mosquito coils and to cooking fumes only among smokers, and no association among lifetime nonsmokers. Interactions between smoking and frequency of cooking, or exposure to incense or mosquito coils were statistically significant and consistent with synergistic effects on lung cancer. The odds ratio (OR) comparing smokers without daily incense or mosquito coil exposure with nonsmokers without daily exposure was 2.80 [95% confidence interval (CI), 1.86-4.21], whereas the OR comparing smokers with daily exposure to the same referent group was 4.61 (95% CI, 3.41-6.24). In contrast, daily exposure to incense or mosquito coils was not associated with lung cancer among nonsmokers (OR = 0.91; 95% CI, 0.72-1.16). We observed the same pattern of associations for smokers without (OR = 2.31; 95% CI, 1.52-3.51) and with (OR = 4.50; 95% CI, 3.21-6.30) daily cooking exposure compared with nonsmokers, with no evidence of an association with daily cooking exposure among nonsmokers.


CONCLUSIONS
Our results suggest that active tobacco smoking not only is an important risk factor for development of lung cancer, but also may cause smokers to be more susceptible to the risk-enhancing effects of other inhalants.
Tang
Li
L
Department of Epidemiology and Public Health, National University of Singapore, Singapore.
Lim
Wei-Yen
WY
Eng
Philip
P
Leong
Swan Swan
SS
Lim
Tow Keang
TK
Ng
Alan W K
AW
Tee
Augustine
A
Seow
Adeline
A
D000368:Aged; D016902:Air Pollution, Indoor / Q000009:adverse effects*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000209:etiology*; D008875:Middle Aged; D012906:Smoke / Q000009:adverse effects*; D012907:Smoking / Q000009:adverse effects*
D012906:Smoke
Am J Epidemiol. 2002 Mar 15;155(6):554-64
11882529
J Toxicol Environ Health A. 2009;72(6):369-73
19199143
J Epidemiol. 2008;18(1):19-25
18305363
J Natl Cancer Inst. 2002 Jun 5;94(11):826-35
12048270
J Toxicol Environ Health A. 2005 Sep;68(17-18):1525-35
16076764
Bull Environ Contam Toxicol. 1994 Dec;53(6):895-901
7881219
J Toxicol Environ Health B Crit Rev. 2008 Jan;11(1):1-15
18176884
Am J Epidemiol. 2007 Mar 15;165(6):634-42
17189590
Mutat Res. 2007 Apr 2;628(2):107-16
17229588
Am J Epidemiol. 2000 Jan 15;151(2):140-7
10645816
J Hazard Mater. 2009 Jul 30;166(2-3):676-85
19131162
Environ Health Perspect. 2007 Jun;115(6):848-55
17589590
Chem Res Toxicol. 2008 Jan;21(1):160-71
18052103
Mutat Res. 1996 Mar 1;367(3):105-14
8600366
Bull Environ Contam Toxicol. 1987 May;38(5):827-33
3555654
Environ Health Perspect. 2003 Sep;111(12):1439-42
12948880
Mutat Res. 1994 Mar 1;305(2):253-64
7510036
CA Cancer J Clin. 2005 Mar-Apr;55(2):74-108
15761078
Mutat Res. 1991 Sep;261(1):21-8
1881406
Sci Total Environ. 2006 Dec 15;372(1):64-75
16979223
Cancer Res. 2006 May 1;66(9):4961-7
16651454
Cancer. 2008 Oct 1;113(7):1676-84
18726993