Environmental tobacco smoke and tobacco related mortality in a prospective study of Californians, 1960-98.
OBJECTIVE
To measure the relation between environmental tobacco smoke, as estimated by smoking in spouses, and long term mortality from tobacco related disease.


METHODS
Prospective cohort study covering 39 years.


METHODS
Adult population of California, United States.


METHODS
118 094 adults enrolled in late 1959 in the American Cancer Society cancer prevention study (CPS I), who were followed until 1998. Particular focus is on the 35 561 never smokers who had a spouse in the study with known smoking habits.


METHODS
Relative risks and 95% confidence intervals for deaths from coronary heart disease, lung cancer, and chronic obstructive pulmonary disease related to smoking in spouses and active cigarette smoking.


RESULTS
For participants followed from 1960 until 1998 the age adjusted relative risk (95% confidence interval) for never smokers married to ever smokers compared with never smokers married to never smokers was 0.94 (0.85 to 1.05) for coronary heart disease, 0.75 (0.42 to 1.35) for lung cancer, and 1.27 (0.78 to 2.08) for chronic obstructive pulmonary disease among 9619 men, and 1.01 (0.94 to 1.08), 0.99 (0.72 to 1.37), and 1.13 (0.80 to 1.58), respectively, among 25 942 women. No significant associations were found for current or former exposure to environmental tobacco smoke before or after adjusting for seven confounders and before or after excluding participants with pre-existing disease. No significant associations were found during the shorter follow up periods of 1960-5, 1966-72, 1973-85, and 1973-98.


CONCLUSIONS
The results do not support a causal relation between environmental tobacco smoke and tobacco related mortality, although they do not rule out a small effect. The association between exposure to environmental tobacco smoke and coronary heart disease and lung cancer may be considerably weaker than generally believed.
School of Public Health, University of California, Los Angeles, CA 90095-1772, USA. jenstrom@ucla.edu
James E
JE
Enstrom
Geoffrey C
GC
Kabat
D000368:Aged; D002140:California / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000401:mortality; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D029424:Pulmonary Disease, Chronic Obstructive / Q000401:mortality; D012306:Risk; D012907:Smoking / Q000401:mortality*; D014028:Tobacco Smoke Pollution / Q000009:adverse effects* / Q000706:statistics & numerical data
D014028:Tobacco Smoke Pollution