Synergistic Interaction Between Polycyclic Aromatic Hydrocarbons and Environmental Tobacco Smoke on the Risk of Obesity in Children and Adolescents: The U.S. National Health and Nutrition Examination Survey 2003-2008

Environ Res. 2014 Nov;135:354-60. doi: 10.1016/j.envres.2014.08.032. Epub 2014 Nov 12.


Background: Polycyclic aromatic hydrocarbons (PAHs) may be obesogens. However, the role of PAHs independent of environmental tobacco smoke (ETS) is unclear, and the interaction between PAHs and ETS remains unknown.

Methods: We performed cross-sectional analyses of urinary concentrations of PAH metabolites, body mass index (BMI), and waist circumference (WC) in 1985 people aged 6-18 years using data from the 2003-2008 U.S. National Health and Nutrition Examination Survey. ETS exposure level was measured as serum cotinine level.

Results: PAH metabolites were positively associated with BMI and WC in both the ETS-unexposed and ETS-exposed groups. The adjusted odds ratios for general obesity defined by age- and sex-specific BMI≥95th percentile across the quartiles of total PAH metabolites were 1, 4.51, 2.57, and 8.09 (Ptrend=0.003) in the ETS-unexposed group and 1, 2.02, 1.83, and 3.86 (Ptrend<0.001) in the ETS-exposed group. However, the association of PAH metabolites with obesity became stronger as serum cotinine levels increased (Pinteraction<0.05). Among those with high ETS exposure, the adjusted odds ratios for general obesity across quartiles of total PAH metabolites were 1, 2.89, 5.26, and 16.29 (Ptrend<0.001). Compared to the low PAH-exposure group without exposure to ETS, the high ETS- and high PAH-exposure group had 33.85- and 17.64-fold greater risks of general and central obesity, respectively.

Conclusion: Environmental exposure to PAHs may be associated with childhood obesity irrespective of ETS. In particular, simultaneous exposure to PAHs and ETS may substantially increase the risk of obesity.

Keywords: Environmental tobacco smoke; Interaction; NHANES; Obesity; Polycyclic aromatic hydrocarbons.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Body Mass Index
  • Child
  • Cotinine / blood
  • Cross-Sectional Studies
  • Humans
  • Multivariate Analysis
  • Nutrition Surveys
  • Obesity / epidemiology*
  • Odds Ratio
  • Polycyclic Aromatic Hydrocarbons / adverse effects*
  • Polycyclic Aromatic Hydrocarbons / urine
  • Risk Factors
  • Tobacco Smoke Pollution / adverse effects*
  • United States / epidemiology
  • Waist Circumference


  • Polycyclic Aromatic Hydrocarbons
  • Tobacco Smoke Pollution
  • Cotinine