A new study has linked passive smoking to 42,000 deaths of nonsmokers in the United States annually that includes 900 babies.
Altogether, annual deaths from secondhand smoke represent nearly 600,000 years of potential life lost - an average of 14.2 years per person - and $6.6 billion in lost productivity, amounting to $158,000 per death, report the researchers.
The study, which involved the first use of a biomarker to gauge the physical and economic impacts of cigarette smoke, revealed that secondhand smoke exposure disproportionately affects African Americans, especially black infants.
The study will be published Thursday, September 20, 2012 in the American Journal of Public Health.
"In general, fewer people are smoking and many have made lifestyle changes, but our research shows that the impacts of secondhand smoke are nonetheless very large," said lead author Wendy Max, PhD, professor of health economics at the UCSF School of Nursing and co-director of the UCSF Institute for Health & Aging. "The availability of information on biomarker-measured exposure allows us to more accurately assess the impact of secondhand smoke exposure on health and productivity. The impact is particularly great for communities of color."
Exposure to secondhand smoke is linked to a number of fatal illnesses including heart and lung disease, as well as conditions affecting newborns such as low birth weight and respiratory distress syndrome.
About a decade ago, the federal Centers for Disease Control and Prevention - using data from the California Environmental Protection Agency - reported that 49,400 adults died annually as a result of secondhand smoke exposure. Additionally, the CDC reported that 776 infants annually died as a result of maternal exposure in utero.
Those widely-cited statistics relied on self-reporting to gauge the impact of secondhand smoke.
The new study led by UCSF shows that the statistics on fatalities resulting from for ischemic heart disease are 25 percent lower than previously reported (34,000 deaths compared to 46,000), but nearly twice as high for lung cancer deaths (7,333 deaths compared to 3,400). The new study also shows higher infant mortality (863 deaths compared to 776).
The researchers used serum cotinine - a biomarker which detects the chemical consequences of exposure to tobacco smoke in the bloodstream - to measure exposure to secondhand smoke. That measurement reflects secondhand exposure in all settings, not just home or work, the authors wrote.
The scientists gauged the economic implications - years of potential life lost and the value of lost productivity - on different racial and ethnic groups.
Mortality was measured in two conditions for adults: lung cancer and ischemic heart disease; and four conditions for infants: sudden infant death syndrome, low birth weight, respiratory distress syndrome, and other respiratory conditions of newborns.
Of the 42,000 total deaths resulting from secondhand smoke, 80 percent were white, 13 percent were black, and 4 percent were Hispanic. The vast majority of deaths were caused by ischemic heart disease. Black babies accounted for a startling high 24 percent to 36 percent of all infant deaths from secondhand smoke exposure, the researchers reported, although blacks represented only 13 percent of the total U.S. population in 2006.
The value of lost productivity per death was highest among blacks ($238,000) and Hispanics ($193,000).
"Black adults had significantly greater exposure rates than did whites in all age groups," the authors wrote. "The highest secondhand smoke exposure was for black men aged 45 to 64 years, followed by black men age 20 to 44 years. Black women aged 20 to 44 years had a higher exposure rate (62.3 percent) than did any other women."
"Our study probably under-estimates the true economic impact of secondhand smoke on mortality," said Max. "The toll is substantial, with communities of color having the greatest losses. Interventions need to be designed to reduce the health and economic burden of smoking on smokers and nonsmokers alike, and on particularly vulnerable groups."
Co-authors are Hai-Yen Sung, PhD, adjunct professor at the UCSF School of Nursing and the Institute for Health & Aging; and Yanling Shi, MS, a staff research associate at the Institute for Health & Aging.
Data was derived from multiple sources including the National Health and Nutrition Examination Survey from 2003-2006, which contained data on nearly 13,000 adults; the 2006 National Health Interview Survey (23,322 adults); and the 2006 Multiple Cause of Death data file (2.4 million deaths).
The research was supported by the Flight Attendants Medical Research Institute, and the California Tobacco Related Disease Research Program.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.