Abstract C40: Organochlorine and organophosphate pesticide exposure in children and adolescents of Mexican origin residing in the Lower Rio Grande Valley of Texas
Authors: Hernandez Mike , Garcia-Prieto Celia , Hernandez-Valero Maria , Patterson Sherri L. , Li Yisheng , Hajek Richard A. , Jones Lovell A. , Hawk Ernest 
Published: May 2016

Abstract
Background: Children and adolescents of Mexican origin residing in the Lower Rio
Grande Valley (LRGV) of Texas, USA were evaluated for risk of exposure to organochlorine (OC) and organophosphate (OP) pesticides. This pilot study summarizes the lipid adjusted serum concentrations of OCs and the creatinine corrected urine concentrations of OPs obtained from study participants.
Methods: The lipid adjusted serum concentrations of OCs (in ppb on a lipid-weight basis) along with creatinine corrected urine concentrations of OPs (in µg/g of creatinine) were measured and compared to the US national data reported by the National Health and Nutrition Examination Survey (NHANES). Descriptive statistics, including geometric means (GMs) and 95% confidence intervals (CIs), were used to summarize the distribution of concentration levels. Scatter plots were generated to visually assess distributions and to identify outlying values relative to the positioning of the NHANES 95th percentile. Half of the limit of detection (LOD) was substituted for cases where concentration levels were below LOD.
Results: Sixty children and adolescents participated in the study, with 58 providing serum and urine samples for OC and OP analyses. Of the 9 OC pesticides analyzed, p,p'-DDE had the largest variability and highest frequency of lipid adjusted serum concentrations above the LOD. The GM for p,p'-DDE was 107.1 (ppb), similar to the GM of 105 (ppb) for p,p'-DDE reported by the NHANES. However, our inspection of the distribution of p,p'-DDE concentrations identified two participants with levels above 1,000 (ppb). Outlying values of 127 and 48.5 (ppb) were also identified for p,p'-DDT and gamma-HCCH, respectively. Of the 6 OP pesticides analyzed and specifically for participants 5 to 11 years of age, creatinine corrected urine concentrations of DMP had the largest variability and contained an outlying value of 64.8 (µg/g). For participants 12 to 18 years of age, the creatinine corrected urine concentrations of all 6 OPs were at or below the 95th percentile reported by the NHANES for adolescents 12 to 19 years of age.
Conclusion: Although the OCs and OPs analyzed in this study were indicative of concentration levels within the distributional range of the US national data reported by the NHANES, the p,p'-DDE concentration levels of two children exceeded the 95th percentile for the US population by more than two-fold. This warrants further investigation given that p,p'-DDE is a known derivative of DDT which has been banned in the US for more than 40 years.
Citation Format: Mike Hernandez, Celia Garcia-Prieto, Maria Hernandez-Valero, Sherri L. Patterson, Yisheng Li, Richard A. Hajek, Lovell A. Jones, Ernest Hawk. Organochlorine and organophosphate pesticide exposure in children and adolescents of Mexican origin residing in the Lower Rio Grande Valley of Texas. [abstract]. In: Proceedings of the Eighth AACR Conference on The Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; Nov 13-16, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2016;25(3 Suppl):Abstract nr C40.