Perfluoroalkyl and polyfluoroalkyl substances and indicators of immune function in children aged 12-19 y: National Health and Nutrition Examination Survey.

BACKGROUND: Perfluoroalkyl and polyfluoroalkyl substances (PFAS) are immunotoxic in laboratory studies. Human studies of immune effects are inconsistent. Using the US National Health and Nutrition Examination Survey (NHANES), we examined PFAS serum concentration and indicators of prevalent immune function among 12-19-y-old children. METHODS: In this cross-sectional study, we examined PFAS serum concentration in relation to measles, mumps, and rubella antibody concentrations in NHANES 1999-2000 and 2003-2004 (n = 1,191) and to allergic conditions and allergic sensitization in NHANES 2005-2006 (n = 640). RESULTS: In adjusted, survey-weighted models, a doubling of perfluorooctane sulfonate (PFOS) concentration among seropositive children was associated with a 13.3% (95% confidence interval (CI): -19.9, -6.2) decrease in rubella antibody concentration and a 5.9% decrease in mumps antibody concentration (95% CI: -9.9, -1.6). We observed no adverse association between exposure and current allergic conditions, including asthma. Children with higher PFOS concentration were less likely to be sensitized to any allergen (odds ratio (OR): 0.74; 95% CI: 0.58, 0.95). CONCLUSION: Increased exposure to several PFAS was associated with lower levels to mumps and rubella antibody concentrations, especially among seropositive individuals. These lower antibody concentrations may indicate a less robust response to vaccination or greater waning of vaccine-derived immunity over time.

Asthma and physical activity in multiracial girls from three US sites.

OBJECTIVE: Studies comparing physical activity levels in children with and without asthma have had mixed results. Our objective was to investigate the association between asthma diagnosis and physical activity and to examine differences in these associations by race/ethnicity, weight status and caregiver education. METHODS: We investigated the association between asthma (defined as report of physician-diagnosed asthma with at least one asthma related symptom) and measures of physical and sedentary activity in a study of 6- to 8-year-old girls in the Breast Cancer and the Environment Research Project. We compared reported activity and pedometer measurements among girls with and without asthma, and examined modification of these associations by race/ethnicity, weight status and caregiver education. RESULTS: Girls (n = 1182) were included with 33.5% White, 4.8% Asian, 30.6% non Hispanic Black and 30.7% Hispanic. Asthma was present in 16.2% of girls. Overall, 38% of girls reported no participation in organized recreational activities and 58% had >2 h/day of television, video game and computer time combined. Girls with asthma whose parents were less educated reported fewer pedometer steps and less non-scheduled activity than girls without asthma with similar caregiver education level. Among girls with asthma, those on a controller medication had higher levels of sedentary activity and more structured physical activity but were less likely to report high intensity physical activity. CONCLUSIONS: Among girls whose parents are less educated, girls with asthma may have lower physical activity levels than girls without asthma. Use of a controller medication may be related to physical and sedentary activity.

Dietary predictors of urinary environmental biomarkers in young girls, BCERP, 2004-7.

BACKGROUND: Exposures of children to phthalates, parabens, and bisphenol-A (BPA) are of concern because of their hormonal potential. These agents are found in a wide range of foods and packaging. We investigated whether intake of certain foods predict exposures to these chemicals in young girls. METHODS: Among 1101 girls (6-8 years at enrollment) from the Breast Cancer and Environment Research Program (BCERP) study, we measured urinary exposure biomarkers for phthalates, parabens, and BPA and assessed dietary intake using 24-h recall 2-4 times. We examined the average daily servings of major and minor food groups categorized as 0 to <0.5, 0.5 to <1 and ≥ 1 servings per day. Items included dairy, eggs, fats, fish, fruit, single grains, meat, non-poultry meats, pasta, poultry and vegetables. Covariate-adjusted least squares geometric means and 95% confidence intervals of creatinine-corrected phthalate and phenol metabolite concentrations in urine were calculated in relation to food intake. RESULTS: Grains, flour and dry mixes and total fish consumption were positively associated with BPA and the sum of four di-2-ethylhexylphthalate (DEHP) urinary metabolite concentrations. Non-fresh vegetables and poultry were both positively associated with BPA and paraben urinary concentrations. Fats, oils and poultry consumption were positively associated with BPA. Whole-fat dairy consumption was associated with ΣDEHP. CONCLUSIONS: Some foods may contribute to child exposures to certain chemicals, and this may constitute modifiable means to reduce these environmental exposures.