Mortality risks associated with environmental tobacco smoke exposure in the United States.

INTRODUCTION

Researchers have presented various estimates of mortality attributable to environmental tobacco smoke (ETS) exposure in the United States, but mortality risk estimates for ETS exposure from U.S. health survey data are generally unavailable.

METHODS

I estimated mortality hazard ratios (HRs) for ETS exposure from Third National Health and Nutrition Examination Survey (NHANES III) data from 1988 to 1994 linked for 4 and 8 years of mortality follow-up. I classified ETS exposure based on observed serum cotinine concentrations (low ETS exposure: <0.1 ng/ml, medium ETS exposure: ≥ 0.1 ng/ml, and <1 ng/ml, and high ETS exposure: ≥ 1 ng/ml and <15 ng/ml) and reported home ETS exposure information. I also estimated ETS exposure among U.S. nonsmokers over time using NHANES III data and continuous NHANES data from 1999 to 2010.

RESULTS

High ETS exposure was associated with higher ischemic heart disease mortality risk (HR = 2.47, 95% CI = 1.04-5.86) among never-smokers during 4 years of follow-up, adjusting for age, sex, race/ethnicity, educational attainment, alcohol consumption, body mass index, high blood pressure, and serious circulatory conditions. The prevalence of medium ETS exposure among nonsmokers decreased from 53.0% (95% CI = 51.5%-54.5%) in NHANES III to 16.7% (95% CI = 15.3%-18.1%) in NHANES from 2005 to 2010.

CONCLUSIONS

I found an association between high ETS exposure and heart disease mortality risk among never-smokers during short-term mortality follow-up using U.S. national health survey data. I also found that ETS exposure among U.S. nonsmokers has substantially decreased in recent decades.