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Secondhand Smoke a Risk for Children Worldwide


Parents worldwide are doing little to protect their children from exposure to secondhand smoke, according to a study by researchers at the Johns Hopkins Bloomberg School of Public Health. Exposure to secondhand smoke has been extensively shown to increase the risk for numerous illnesses and premature death. The household study, conducted in 31 countries, found that 82 percent of parents who smoked reported smoking around their children. Measurements of nicotine levels from household air and children’s hair samples also indicated high exposure to secondhand smoke among those living with a smoker. The study is among the first to demonstrate that secondhand smoke is a global concern, particularly for children. It was published on February 28 in the online version of the American Journal of Public Health and will appear in the journal’s April 2008 print edition.

According to the findings, concentrations of nicotine in the air were 17 times higher in households with a smoker compared to those without. Air concentrations were 12.9 times higher in households that permitted smoking indoors, compared to those that voluntarily restricted indoor smoking. Median air nicotine levels in households with smokers were highest in Europe, followed by Latin America and Asia.

Nicotine was detected in hair samples in 78 percent of children living with a smoker and 59 percent of those who did not live with a smoker. In most cases, hair nicotine levels were positively correlated with nicotine air concentrations.

“Our research clearly shows that parents are failing to protect their children from secondhand smoke exposure, perhaps because they are unaware of the risks” said lead author, Heather Wipfli, PhD, project director at the Bloomberg School’s Institute for Global Tobacco Control. “The results highlight the need to improve public awareness of the importance of going outside to smoke to limit the exposure to children living in the home.”

A related study, also published in the American Journal of Public Health, concluded that paternal smoking diverts money from basic necessities to cigarettes, putting children at greater risk for chronic malnutrition. Richard Semba, MD, MPH, a professor with the Johns Hopkins School of Medicine, and his colleagues found that paternal smoking was associated with increased mortality among infants and children under age 5 in Indonesia.

“Tobacco control should be considered as part of the strategy for reducing child mortality,” said Semba.

“Secondhand Smoke Exposure Among Women and Children: Evidence from 31 Countries” was written by Heather Wipfli, PhD; Erika Avila-Tang, PhD, MHS; Ana Navas-Acien, MD, PhD, MPH; Sungroul Kim, PhD; Georgiana Onicescu, ScM; Jie Yuan, BS; Patrick Breysse, PhD, MHS; and Jonathan Samet, MD, MS.

Support for the study was provided by the Flight Attendants Medical Research Institute (FAMRI) and a Center of Excellence Award to the Johns Hopkins Medical Institutions. Support was also provided by the National Institutes of Health through the Fogarty International Center.

“Paternal Smoking and Increased Risk of Infant and Under-5 Mortality in Indonesia” was written by Richard Semba, MD, MPH; Saskia de Pee, PhD; Kai Sun, MS; Cora M. Best, MHS; Mayang Sari, MSc; and Martin W. Bloem, MD, PhD.

The study was supported by a Lew R. Wasserman Merit Award from Research to Prevent Blindness to Richard Semba.

For additional information, please contact Tim Parsons at 410-955-7619 or at