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Dacula, GA, United States

Jain R.B.,2959 Estate View Court
Environmental Research | Year: 2015

Data from National Health and Nutrition Examination Survey for the years 2011-2012 were used to evaluate variability in the observed levels of 20 urinary metabolites of volatile organic compounds (VOCs) by age, gender, and race/ethnicity among children aged 6-11 years. Exposure to environmental tobacco smoke was positively associated with the levels of selected metabolites of acrylonitrile, 1,3-butadiene, cyanide, and propylene oxide in a dose-response manner. Levels of the selected metabolites of acrolein, acrylonitrile, 1,3-butadiene, styrene, toluene, and xylene decreased with increase in age. Levels of 1-bromopropane decreased with number of rooms in the house but the reverse was true for 1,3-butadiene, carbon-disulfide, and N,N-dimethylformamide. Levels of most of the 20 metabolites did not vary with gender. Non-Hispanic white children had higher adjusted levels of N-Acetyl-S-(3,4-dihydroxybutyl)-. l-cysteine (DHBMA), N-Acetyl-S-(N-methylcarbamoyl)-. l-cysteine (AMCC), and phenylglyoxylic acid (PGA) than non-Hispanic black children. Non-Hispanic white children had statistically significantly higher adjusted levels of N-Acetyl-S-(2-carbamoyl-2-hydroxyethyl)-. l-cysteine (GAMA), trans, trans-Muconic acid (MU), and N-Acetyl-S-(N-methylcarbamoyl)-. l-cysteine (AMCC) than non-Hispanic Asian children but statistically significantly lower levels of N-Acetyl-S-(n-propyl)-. l-cysteine (BPMA) than non-Hispanic Asian children. Non-Hispanic Asian children had the lowest levels of 13 of the 20 metabolites among four major racial/ethnic groups but highest levels for three metabolites. For selected metabolites of acrolein, acrylamide, acrylonitrile-vinyl chloride-ethylene oxide, benzene, 1,3-butadien, crotonaldehyde, cyanide, ethylbenzene-styrene, and toluene, children had statistically significantly higher levels than nonsmoking adults. These results demonstrate how vulnerable children are to being exposed to harmful chemicals like VOCs in their own homes. © 2015 Elsevier Inc. Source


Use of maximum likelihood estimation procedures with multiple imputations to replace observations below the limit of detection (LOD) has been recommended. There is concern that the use of multiple imputations may introduce variability in the data resulting in different conclusions every time the same data are statistically analyzed. We analyzed data from National Health and Nutrition Examination Survey for 7 perfluorinated and 7 polybrominated diphenyl ethers to address these concerns. Data for each variable were subjected to 10 different iterations of statistical analysis. All observations below LOD were replaced by maximum likelihood estimation procedures with 5 imputations. The maximum variation in computing unadjusted geometric means over 10 iterations of analysis was about 2.5%. Unless the percent observations below LOD was more than 40%, maximum variation in computing adjusted geometric means was less than 1.5%. Maximum variation for computing adjusted geometric standard deviation was less than 6%. Except for border line comparisons, significance probabilities for pairwise comparisons did not vary enough to render contrasts from being statistically significant to statistically non-significant or vice versa. Similar conclusions applied to significance probabilities for regression slopes. The use of more than one multiply imputed variable in a regression model was not found to be of concern. The results show that the use of multiple imputations does not generate additional variabilities in the estimates of these statistics beyond tolerable statistical noise. However, when the percent observations in the data are relatively high, there is some possibility of obtaining disparate results. © 2015 Elsevier Ltd. Source


Data from National Health and Nutrition Examination Survey for 2005-2012 were used to study the trends and variability in the levels of urinary thiocyanate (u-SCN), perchlorate (u-P8), and nitrate (u-NO3) by gender, race/ethnicity, active smoking, and exposure to environmental tobacco smoke (ETS) at home for those aged 12-19 and ≥. 20 years old. For those aged ≥. 20 years, adjusted levels of u-SCN, u-P8, and u-NO3 (i) were lower for males than females (p < 0.01), and (ii) were higher for non-Hispanic white (NHW) than non-Hispanic black (NHB) (p < 0.01). Also, for those aged ≥. 20 years NHB had higher adjusted levels than Mexican American (MA) for u-SCN (p < 0.01) but NHB had lower adjusted levels than MA for u-P8 (p < 0.01) and u-NO3 (p < 0.01). For those aged 12-19 years, adjusted levels of u-SCN, u-P8, and u-NO3 did not vary by gender (p > 0.05), and adjusted levels of u-P8 and u-NO3 for NHB were lower than for NHW (p < 0.01) as well as higher for NHB than MA for u-SCN (p < 0.01) and lower for NHB than MA (p < 0.01) for u-P8 and u-NO3. Among those aged ≥. 20 years, active smoking was associated with higher adjusted levels of u-SCN (p < 0.01) in a dose-response manner and active smoking was associated with lower adjusted levels of u-P8 (p < 0.01) in a dose-response manner. Exposure to ETS was associated with higher adjusted levels of u-SCN (p = 0.02) and lower adjusted levels of u-P8 (p < 0.01) among ≥. 20 years old. Adjusted levels of u-P8 decreased over 2005-2012 among both 12-19 (p < 0.01) and ≥. 20 years old (p = 0.04). There was borderline increase in the adjusted levels of u-NO3 for those aged ≥. 20 years (p = 0.05) over 2005-2012. © 2016 Elsevier B.V. Source


Jain R.B.,2959 Estate View Court
Environmental Science and Pollution Research | Year: 2016

Using data from the National Health and Nutrition Examination Survey for the period 2003–2012, the objective of this study was to evaluate trends in blood lead levels (BLL) among children aged 1–5 and 6–11 years and smoker and nonsmoker adolescents aged 12–19 years. Regression models with log10 transformed values of BLLs as dependent variable were fitted to evaluate how gender, race/ethnicity, smoking, and exposure to secondhand smoke at home affect BLLs. Irrespective of age, gender, and race/ethnicity, BLLs declined over the study period (p ≤ 0.01). Overall, adjusted BLLs declined by 0.00114 μg/dL for every 2 years. Children aged 1–5 years had about 50 % higher BLLs than smoker adolescents, about 75 % higher BLLs than nonsmoker adolescents, and about 45 % higher BLLs than children aged 6–11 years. While overall, children aged 1–5 years with BLL ≥ 5 μg/dL made up 3.24 %, 7.8 % non-Hispanic Black children aged 1–5 years had BLL ≥ 5 μg/dL. Males were found to have higher adjusted BLLs than females, and non-Hispanic Blacks were found to have higher adjusted BLLs than non-Hispanic Whites. Higher poverty income ratio was associated with lower adjusted BLLs (β = −0.02916, p < 0.01). Children living in owner-occupied homes had lower adjusted BLLs than children living in renter-occupied homes. BLLs increased with increase in number of smokers smoking inside the home (β = 0.02496, p = 0.02). In conclusion, while BLLs have declined for all age groups, genders, and races/ethnicities, certain races/ethnicities like non-Hispanic Blacks continue to have substantially higher BLLs than non-Hispanic Whites. © 2016 Springer-Verlag Berlin Heidelberg Source


Polycyclic aromatic hydrocarbons (PAH) are potentially mutagenic and carcinogenic and as such their exposure is of serious concern. Regression models to estimate the total concentration of polycyclic aromatic hydrocarbon metabolites (∑PAH) in urine were developed. Using data from National Health and Nutrition Examination Survey for the years 2003-2008 and 2011-2012, regression models were developed to estimate ∑PAH in urine. The performance of the fitted models were computed by comparing percent predicted values located between 0 and 5%, 5-10%, 15-20% and >20% of the observed values. While data for 2003-2008 were used to fit the regression models, the data for 2011-2012 were solely used to evaluate the performance of the fitted models. R2 of the fitted model was 94.7%. About 46% of the predicted values for the 2003-2008 data and over 48% of the predicted values for the 2011-2012 data were found to be between 0 and 10% of the observed values. In order to use these models, in addition to age, gender, and smoking status, and optionally race/ethnicity, the knowledge of the levels of only 1-hydroxynaphthalene, 2-hydroxynaphthalene, and 9-hydroxyfluorene is necessary. Models that optionally require the knowledge of the levels of urine creatinine were also developed. © 2015 Elsevier Ltd. Source

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