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Weber, Till

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  • Veröffentlichung
    Nonylphenol (NP) exposure in Germany between 1991 and 2021: urinary biomarker analyses in the German Environmental Specimen Bank (ESB)
    (2022) Ringbeck, Benedikt; Kolossa-Gehring, Marike; Bury, Daniel; Weber, Till
    Nonylphenol (NP) is a high production volume chemical with a wide range of uses, e.g. in NP ethoxylates (NPEO). NP and NPEO have become ubiquitous in the environment and are considered of concern due to their general ecotoxicity and endocrine disrupting properties. However, knowledge on human exposure is scarce. In this study, we analyzed novel NP metabolites (OH-NP and oxo-NP) as robust biomarkers of exposure in 24h-urine samples from the German Environmental Specimen Bank (ESB). This enables us to reliably determine the individual NP body burden and to retrospectively evaluate NP exposure over the past 30 years. We analyzed 660 urine samples from eleven sampling years between 1991 and 2021. All samples were from young German adults between 20 and 29 years of age. OH-NP was quantifiable in all samples until 2017. In 2019 and 2021, the frequency of samples above the LOQ dropped to 90% and 77%, respectively. Median OH-NP concentrations significantly decreased from 4.32 (micro)g/L in 1991 to 0.70 (micro)g/L in 2021. OH-NP and oxo-NP levels correlated strongly, but oxo-NP concentrations and detections were considerably lower, in line with its known lower metabolic conversion. Reverse dosimetry back-calculated daily intakes (DI) of NP, based on OH-NP, decreased by almost a factor of four from medians of 0.16 (micro)g/(kg bw*d) in 1991 to 0.04 (micro)g/(kg bw*d) in 2021, respectively. The major drop took place only after 2012. This came as a surprise, because strict restrictions had been enacted much earlier in the EU, in 2003. All NP DIs were below the provisional tolerable daily intake of 5 (micro)g/(kg bw*d) from the Danish Environmental Agency. DIs back-calculated from the ESB biomonitoring data agree well with calculations from food. This indicates to contaminated foodstuff as a major source of exposure. The time lag of regulatory restrictions to decreasing human exposure levels, the general lack of knowledge on exposure levels in susceptible populations such as children, and the ongoing worldwide use of NP underline the urgent need to continue monitoring NP exposures in Germany and worldwide. With these novel NP biomarkers, we provide a robust and sensitive tool for exposure and risk assessments, complementing environmental monitoring. © 2022 The Authors
  • Veröffentlichung
    Increasing exposure to the UV filters octocrylene and 2-ethylhexyl salicylate in Germany from 1996 to 2020: Human biomonitoring in 24-h urine samples of the German Environmental Specimen Bank (ESB)
    (2023) Bury, Daniel; Ebert, Katharina E.; Kolossa-Gehring, Marike; Weber, Till
    The UV filters octocrylene (OC) and 2-ethylhexyl salicylate (EHS) are commonly used in sunscreens and frequently detected in environmental media. However, knowledge on human exposures is scarce. In this human biomonitoring (HBM) study, we analyzed concentrations of exposure biomarkers specific to OC (CPAA, DOCCA, 5OH-OC) and EHS (5OH-EHS, 5oxo-EHS, 5cx-EPS) in 24-h urine samples (n=420) from the German Environmental Specimen Bank (ESB). These samples were collected from German students (20-29 years; 30 males/30 females per year) between 1996 and 2020 (4-year intervals; collection in winter). We found continuously increasing OC and EHS exposures (Jonckheere-Terpstra; p < 0.001) documented by very few to no samples with concentrations of the most sensitive biomarkers CPAA and 5cx-EPS above the limit of quantification (LOQ) in 1996 (5 % and 0 %, respectively) and reaching 100 % and 93 % above the LOQ in 2016, with median concentrations of 4.79 and 0.071 (micro)g/L, respectively. In 2020, biomarker concentrations slightly decreased to 3.12 (micro)g/L CPAA (97 %>LOQ) and 0.060 (micro)g/L 5cx-EPS (88 %>LOQ). This general trend was confirmed by the other biomarkers, however at lower detection rates. Based on metabolite excretion in the 24-h urine samples and human toxicokinetic data, we calculated maximum daily intakes (DI) of 17 (micro)g/(kg bw * d) OC and 59 (micro)g/(kg bw * d) EHS. Based on a derived no-effect level (DNEL) of 0.8 mg/(kg bw * d), the OC exposures of individuals in our study did not indicate any health risk. Similarly, for EHS all biomarker concentrations were well below the HBM-I values of 12 (micro)g/L 5OH-EHS and 11 (micro)g/L 5cx-EPS. Our data proves the general applicability of specific OC and EHS metabolites for HBM in the general population and shows clearly increasing exposures. Higher (co-)exposures must be expected in populations with increased sunscreen use such as (summer) vacationers, children and outdoor workers. © 2023 The Author(s).