USC study suggests early life exposure to near-road air pollution contributes to increased obesity risk in children
A study lead by a team from the University of Southern California has found that higher exposure to early life near-road air pollution (NRAP) increased the rate of change of childhood body mass index (BMI) and resulted in a higher attained BMI at age 10 years that were independent of later childhood exposures. These findings suggest that elevated early life NRAP exposures contribute to increased obesity risk in children.
An open-access paper on the study is published in the journal Environmental Health.
In the United States, approximately 32% of children 2 to 19 years were overweight or obese in 2011–2012. High prevalence of childhood obesity present significant clinical and public health problems since obese children are more likely to become obese adults and are at a greater risk for developing type 2 diabetes and cardiovascular disease. Despite decades of diet and physical activity interventions, the prevalence of childhood obesity remains high. Previous studies have shown that increased near-roadway air pollution (NRAP) exposure and increased traffic density during childhood contributes to increased obesity risk in children. These findings suggest that modifiable environmental factors such as air pollution exposures may be contributing to the obesity epidemic.
… Because in utero and first year of life are important developmental periods that influence growth, increased NRAP exposure during these critical periods may be contributing to future obesity risk through altered growth trajectories resulting in faster childhood BMI growth. The objective of this study was to examine the relationships between in utero and first year of life NRAP exposures with longitudinal measurements of BMI in a subset of Southern California chil- dren enrolled in the Children’s Health Study (CHS).—Kim et al.
Participants in the Children’s Health Study enrolled from 2002 to 2003 with annual visits over a four-year period and who changed residences before study entry were included (n = 2318). Annual height and weight were measured and lifetime residential NRAP exposures including in utero and first year of life periods were estimated by NOx using the California line-source dispersion model.
Linear mixed effects models assessed in utero or first year near-road freeway and non-freeway NOx exposures and BMI growth after adjusting for age, sex, race/ethnicity, parental education, Spanish questionnaire, and later childhood near-road NOx exposure.
A two-standard deviation difference in first year of life near-road freeway NOx exposure was associated with a 0.1 kg/m2 (95% confidence interval (CI): 0.03, 0.2) faster increase in BMI growth per year and a 0.5 kg/m2 (95% CI: 0.02, 0.9) higher attained BMI at age 10 years.
Jeniffer S. Kim, Tanya L. Alderete, Zhanghua Chen, Fred Lurmann, Ed Rappaport, Rima Habre, Kiros Berhane and Frank D. Gilliland (2018) “Longitudinal associations of in utero and early life near-roadway air pollution with trajectories of childhood body mass index” Environmental Health 17:64 doi: 10.1186/s12940-018-0409-7