Exposure to the Non-Phthalate Plasticizer 1,2-Cyclohexane Dicarboxylic Acid, Diisononyl Ester (DINCH) in Portuguese Children

摘要

Di-iso-nonyl-cyclohexane-1,2-dicarboxylate (DINCH) is used as substitute for High Molecular Weight (HMW) phthalate plasticizers like di (2-ethylhexyl) phthalate (DEHP) and the diisononyl phthalate (DiNP). The available data suggests that DINCH, contrary to phthalates such as DEHP and DINP, is neither an endocrine disruptor nor a reproductive toxicant. Similar to the phthalates, DINCH is only dissolved in the polymer and not chemically bound to it. Thus, due to the ongoing substitution process DINCH exposures of the general population seems likely to occur. The aim of this study was to evaluate the exposure of a group of 112 children from Portugal, divide in two groups: i) diagnosed for obesity/overweight (cases) and ii) healthy weight (controls). Samples were collected during the years 2014 and 2015. Oxidized DINCH metabolites (OH-MINCH, cx-MINCH and oxo-MINCH) were analyzed after enzymatic hydrolysis via on-line HPLC-MS/MS with isotope quantification. In this study, a detection rate of 100% for OH-MINCH and cx-MINCH, and of 99% for oxo-MINCH was achieved. The median creatinine adjusted (95th percentile) values were of 1.16 ug/g (8.79) for cx-MINCH, 1.09 ug/g (7.22) for oxo-MINCH, and 2.14 ug/g (17.25) for OH-MINCH. For the unadjusted concentrations, the median (95th percentile) values were of 1.08 μg/L (7.33) for cx-MINCH, 1.10 μg/L (7.54) for oxo-MINCH, and 2.14 ug/L (15.91) for OH-MINCH. No significant differences were observed between the exposure levels of the case and the control. To the best of our knowledge, the levels of DINCH urinary metabolites have not been yet reported for the Iberian population. The results show a widespread exposure in the participating children, indicating a possible similar scenario for the overall Portuguese population. Acknowledgments: L Correia-Sa is grateful to FCT by the grant (SFRH/BD/87019/2012), financed by POCH, subsidized by Fundo Social Europeu and Ministerio da Ciencia, Tecnologia e Ensino Superior.