Since 2011 the German federal state North Rhine-Westphalia has been investigating the exposure of children aged 2 to 6 years to pollutants. Human biomonitoring data collected from 3 cycles (2011 to 2017) provide important information on children's exposure to pollutants. 23 biomarkers were identified that had a detection rate of more than 50 % in at least 2 cycles. For 8 of these biomarkers a statistically significant decrease in exposure was found. From the group of phthalates these include the metabolites mono-n-butyl phthalate (MnBP), mono-benzyl phthalate (MBzP), mono-(2-ethylhexyl) phthalate (MEHP) and 7oxo-mono-methyloctyl phthalate (oxoMINP), for the preservatives methyl paraben (MeP), ethyl paraben (EtP) and nPropyl paraben (nPrP) as well as glyphosate (GLY) from the group of herbicides. A significant increase in exposure was found for 3 biomarkers. These include cyclohexane-1,2-dicarboxylic acid mono- hydroxyisononylester (MINCH) from the group of plasticisers, N-methylmalonamic acid (NMMA) from the group of preservatives and 3-phenoxy-benzoic acid (3-PBA) from the group of insecticides. Overall the results show that children's exposure to many critical compound like phthalates and parabens is decreasing. For some others, however, exposure is increasing. Continued collection of human biomonitoring data is necessary to track the development of exposure in the future.

TPS 622: Exposure to flame retardants and plasticizers, Johan Friso Foyer, Floor 1, August 26, 2019, 3:00 PM - 4:30 PM Background/Aim: Children are frequently in contact with a range of consumer products which may contain plasticizers like phthalates. Many of these substances are concerning for health, for example toxic for reproduction. Compared to other age groups only few epidemiological studies about the internal phthalate exposure of preschool children are available. This study aims to assess the current phthalate exposure in German preschool children and to compare the obtained data with results from previous studies, focusing on the same age group, to detect tendencies of exposure. Furthermore, the data will be compared with health evaluation criteria. Methods: Within this cross-sectional study, the urine of 251 children (2-6 years) in North Rhine-Westphalia was collected in 2017/18 and analysed for ten metabolites of nine selected phthalates. The estimated daily intakes of the different phthalates were determined via back-calculation and compared to tolerable daily intakes (TDI). Results: Five metabolites showed values far predominantly below the limit of quantification. The highest median urinary concentration was found for mono-iso-butylphthalate (MiBP) (48 µg/L), followed by mono-n-butylphthalate (17 µg/L), mono(2-ethyl-5-hydrohexyl)phthalate (9,7 µg/L), mono(2-ethyl-5-oxohexyl)phthalate (7,5 µg/L), and 7-oxo-mono-iso-nonylphthalate (3,9 µg/L). Analyzing data from previous studies, a continuous decrease for the last 15 years was observed for all these metabolites with the exception of MiBP. The TDI for di-iso-butylpthalate (DiBP), the parent substance of MiBP, was exceeded in 10% of the study population. For all other parent substances of the metabolites the exposure fell below the specific TDI´s. Conclusions: A continuous decrease of exposure in the last 15 years was observed for most phthalate metabolites, though this tendency was not found for MiBP. Because a high proportion (10%) of our study population exceeds the TDI for DiBP the exposure to this harmful phthalate should be reduced, especially to protect the health of children between 2 and 6 years.

TPS 623: Exposures to pesticides, Johan Friso Foyer, Floor 1, August 26, 2019, 3:00 PM - 4:30 PM Background/Aim: Pesticides are frequently used in agriculture and consumer products. In order to determine human exposure to these pesticides, their metabolites or the parent substance are usually analyzed in urine samples. Only for a few pesticides specific biomarkers are available which means that they can be used for a health based risk assessment on the basis of Acceptable Daily Intakes (ADIs). The aim of this study is to assess the internal exposure of German preschool children to various pesticide groups. For those pesticides with specific biomarkers the daily intake should be calculated and compared to ADIs. Methods: The urine of 95 german preschool children between 3 and 6 years was analysed for 8 metabolites of organophosphate insecticides, 8 metabolites of pyrethroids, 4 metabolites of neonicotinoids and glyphosate. With an established toxicokinetic model we calculated the intake for compounds for which a specific biomarker is available. Results: The highest concentrations in our urine samples could be found for the metabolites of organophosphate insecticides followed in order by pyrethroides, neonicotinoides and glyphosate. Quantitatively most relevant are the organophosphate insecticides dimethylthiophosphate, dimethylphosphate, trichloro-2-pyridinol (TCPy) and nitrophenol with median levels between 1.3 and 4.5 µg/L. The urinary concentrations of the specific biomarker TCPy showed that approximately 5 % of our study group succeeded the ADI for chlorpyrifos. The estimated daily intake values for the pyrethroid deltamethrin and glyphosate were found to be far below their corresponding ADI. Conclusion: Preschool children from Germany were found to be exposed to a wide variety of pesticides. Of the compounds we studied, organophosphate insecticides showed the highest relevance. Unfortunately, most of the measured pesticide metabolites are considered as nonspecific biomarkers and therefore cannot be used for health risk assessment. Exposure to the organophosphate insecticide chlorpyrifos may pose a public health concern for some children in preschool age.