Exposure Trends to the Non-phthalate Plasticizers DEHTP, DINCH, and DEHA in Children from 2012 to 2017: The Hokkaido Study.

Phthalates owing to their endocrine-disrupting effects are regulated in certain products, leading to their replacement with substitutions such as di-2-ethylhexyl terephthalate (DEHTP), 1,2-cyclohexane dicarboxylic acid di(isononyl) ester (DINCH), and di(2-ethylhexyl) adipate (DEHA). However, information on human exposure to these substitutes, especially in susceptible subpopulations such as children, is limited. Thus, we examined the levels and exposure trends of DEHTP, DINCH, and DEHA metabolites in 7 year-old Japanese school children. In total, 180 urine samples collected from 2012 to 2017 were used to quantify 10 DEHTP, DINCH, and DEHA metabolites via isotope dilution liquid chromatography with tandem mass spectrometry. DEHTP and DINCH metabolites were detected in 95.6 and 92.2% of the children, respectively, and DEHA was not detected. This study, annually conducted between 2012 and 2017, revealed a significant (p < 0.05) 5-fold increase in DEHTP metabolites and a 2-fold increase in DINCH metabolites. However, the maximum estimated internal exposures were still below the health-based guidance and toxicological reference values. Exposure levels to DEHTP and DINCH have increased considerably in Japanese school children. DEHA is less relevant. Future studies are warranted to closely monitor the increasing trend in different aged and larger populations and identify the potential health effects and sources contributing to increasing exposure and intervene if necessary.

Parabens in urine of children and adolescents in Germany - human biomonitoring results of the german environmental survey 2014-2017 (GerES V).

Parabens are antimicrobial preservatives used in a wide range of consumer products such as personal care products, cosmetics, pharmaceuticals, and food. Consequently, the general population is ubiquitously exposed to these substances via dermal absorption, ingestion, and inhalation. Parabens promote estrogenic activity and are hence under assessment as endocrine disrupting substances. Urine samples from 3- to 17-year-old children and adolescents (N = 516) living in Germany were analysed for concentrations of nine parabens in the population representative German Environmental Survey for Children and Adolescents 2014-2017 (GerES V). Detection rates and urinary concentrations of the parabens decreased with increasing length of the alkyl chain. Methyl paraben was quantified in 97% of the samples with a geometric mean (GM) concentration of 7.724 µg/L (6.714 µg/gcreatinine), ethyl paraben was quantified in 69% (GM: 0.943 µg/L and 0.825 µg/gcrea), and n-propyl paraben in 31% (GM: 0.563 µg/L and 0.493 µg/gcrea). Concentrations of iso-propyl paraben, butyl paraben, iso-butyl paraben, and benzyl paraben were below the limit of quantification in most samples. Pentyl paraben and heptyl paraben were not detected in any of the samples. Paraben concentrations in urine were found to be associated with frequent usage of leave-on personal care products and cosmetics. Cumulative exposure to parabens (back-calculated daily intakes, expressed as hazard index) was found to be on a level raising concern in up to 14% of the population, mainly driven by n-propyl paraben, and depending on the level of conservativeness and point-of departures used for calculation.

Human-Biomonitoring derived exposure and Daily Intakes of Bisphenol A and their associations with neurodevelopmental outcomes among children of the Polish Mother and Child Cohort Study.

BACKGROUND: Bisphenol A (BPA) is an industrial chemical mostly used in the manufacture of plastics, resins and thermal paper. Several studies have reported adverse health effects with BPA exposures, namely metabolic disorders and altered neurodevelopment in children, among others. The aim of this study was to explore BPA exposure, its socio-demographic and life-style related determinants, and its association with neurodevelopmental outcomes in early school age children from Poland. METHODS: A total of 250 urine samples of 7 year-old children from the Polish Mother and Child Cohort Study (REPRO_PL) were analyzed for BPA concentrations using high performance liquid chromatography with online sample clean-up coupled to tandem mass spectrometry (online-SPE-LC-MS/MS). Socio-demographic and lifestyle-related data was collected by questionnaires or additional biomarker measurements. Emotional and behavioral symptoms in children were assessed using mother-reported Strengths and Difficulties Questionnaire (SDQ). Cognitive and psychomotor development was evaluated by Polish adaptation of the Intelligence and Development Scales (IDS) performed by trained psychologists. RESULTS: Urinary BPA concentrations and back-calculated daily intakes (medians of 1.8 µg/l and 46.3 ng/kg bw/day, respectively) were similar to other European studies. Urinary cotinine levels and body mass index, together with maternal educational level and socio-economic status, were the main determinants of BPA levels in Polish children. After adjusting for confounding factors, BPA has been found to be positively associated with emotional symptoms (ß: 0.14, 95% CI: 0.022; 0.27). Cognitive and psychomotor development were not found to be related to BPA levels. CONCLUSIONS: This study represents the first report of BPA levels and their determinants in school age children in Poland. The exposure level was found to be related to child emotional condition, which can have long-term consequences including social functioning and scholastic achievements. Further monitoring of this population in terms of overall chemical exposure is required.

Effect-based evaluation of ozone treatment for removal of micropollutants and their transformation products in waste water.

The aim of this interdisciplinary research project in North Rhine-Westphalia (NRW), Germany, entitled "Elimination of pharmaceuticals and organic micropollutants from waste water" involved the conception of cost-effective and innovative waste-water cleaning methods. In this project in vitro assays, in vivo assays and chemical analyses were performed on three municipal waste-water treatment plants (WWTP). This publication focuses on the study of the in vitro bioassays. Cytotoxic, estrogenic, genotoxic and mutagenic effects of the original as well as enriched water samples were monitored before and after wastewater treatment steps using MTT and PAN I, ER Calux and A-YES, micronucleus and Comet assays as well as AMES test. In most cases, the measured effects were reduced after ozonation, but in general, the biological response depended upon the water composition of the WWTP, in particular on the formed by-products and concentration of micropollutants. In order to be able to assess the genotoxic and/or mutagenic potential of waste-water samples using bioassays like Ames test, Comet assay or micronucleus test an enrichment of the water sample via solid-phase extraction is recommended. This is in agreement with previous studies such as the "ToxBox"-Project of the Environmental Agency in Germany.

Perfluoroalkyl acids (PFAAs) and anthropometric measures in the first year of life: Results from the Duisburg Birth Cohort.

In the context of the Duisburg Birth Cohort, this retrospective cohort study provides results of internal exposure to perfluorooctanoic acid (PFOA), perfluorooctanesulfonic acid (PFOS), and perfluorohexanesulfonic acid (PFHxS) in 156 mother-child pairs, and investigates whether and to what extent in utero exposure of these chemicals at German background levels exerts an effect on newborn and infant weight and length, and weight in relation to length expressed by ponderal index, in order to examine whether any reduction in weight is disproportionate to length. The levels of PFOA, PFOS, and PFHxS were determined in 81 maternal and 83 umbilical cord stored frozen plasma samples and 105 umbilical cord blood samples. Calculated factors were used to convert umbilical cord values to maternal levels. Weights and lengths were retrieved at birth and at 1, 4, 6, and 12 mo from examination booklets and ponderal index (kg/m3) was calculated. Subsequently, correlations were assessed using multiple linear regressions and generalized estimation equations with each of the measures as a continuous outcome variable and with PFOA, PFOS, and PFHxS concentration quartiles as categorized predictor variables, while adjusting for relevant covariates. PFOA, PFOS, and PFHxS were generally within German background exposure levels. There was a significant association between PFOA, PFOS, and PFHxS concentration quartiles and decrease in ponderal index at birth but not weight or height. A nonsignificant negative association between exposure to all three compounds and birth weight was noted. Follow-up showed no sustained effect of the PFAA on anthropometric measures during the first year.

Prenatal exposure to DDE and PCB 153 and respiratory health in early childhood: a meta-analysis.

BACKGROUND: Persistent organic pollutants may affect the immune and respiratory systems, but available evidence is based on small study populations. We studied the association between prenatal exposure to dichlorodiphenyldichloroethylene (DDE) and polychlorinated biphenyl 153 (PCB 153) and children's respiratory health in European birth cohorts. METHODS: We included 4608 mothers and children enrolled in 10 birth cohort studies from 7 European countries. Outcomes were parent-reported bronchitis and wheeze in the first 4 years of life. For each cohort, we performed Poisson regression analyses, modeling occurrences of the outcomes on the estimates of cord-serum concentrations of PCB 153 and DDE as continuous variables (per doubling exposure) and as cohort-specific tertiles. Summary estimates were obtained through random-effects meta-analyses. RESULTS: The risk of bronchitis or wheeze (combined variable) assessed before 18 months of age increased with increasing DDE exposure (relative risk [RR] per doubling exposure = 1.03 [95% confidence interval = 1.00-1.07]). When these outcomes were analyzed separately, associations appeared stronger for bronchitis. We also found an association between increasing PCB 153 exposure and bronchitis in this period (RR per doubling exposure = 1.06 [1.01-1.12]) but not between PCB 153 and wheeze. No associations were found between either DDE or PCB 153 and ever-wheeze assessed after 18 months. Inclusion of both compounds in the models attenuated risk estimates for PCB 153 tertiles of exposure, whereas DDE associations were more robust. CONCLUSION: This large meta-analysis suggests that prenatal DDE exposure may be associated with respiratory health symptoms in young children (below 18 months), whereas prenatal PCB 153 levels were not associated with such symptoms.

Implementing a multimodal intervention using local resources to improve hand hygiene compliance in a comprehensive specialized hospital in Mekelle, Northern Ethiopia.

BACKGROUND: Hand hygiene (HH) is known to be the most effective practice to reduce Healthcare-associated infections (HAIs). The main barriers to HH practices among healthcare workers (HCWs) in Sub-Saharan Africa are heavy workload, infrastructural deficits, and poorly positioned facilities. There is limited data on HH compliance and particularly on the impact of the World Health Organization's (WHO) multimodal HH strategy in low- and middle-income countries. This study aimed to provide insights into a strategy to implement the WHO concept adapted to local conditions and obstacles encountered at a tertiary university hospital in Mekelle, Tigray, Ethiopia. METHODS: We conducted a study aiming at increasing the quality of the HH practice of HCWs using the WHO HH improvement strategy. The study adopted a pre-and post-interventional design from April 2018 to May 2019. In the pre-intervention phase, a baseline infrastructural survey was made. The intervention consisted of in-house production of hand sanitizer and dispensers for every patient bed, staff education and motivation, and implementation of a multidisciplinary infection prevention committee. The intervention was followed by two one-week compliance observations of HH practice among HCWs within the six months post-intervention period and microbiological sample collection from HCWs' hands to assess the quality of HH. RESULTS: We observed 269 (baseline), 737 (first follow-up) and 574 (second follow-up) indications for HH among HCWs. The overall baseline hand rub compliance was 4.8%, which significantly increased to 37.3% (first follow-up) and 56.1% (second follow-up) (p < 0.0001). Consistent and significant increases in hand rub compliance during the entire follow-up period were observed before touching a patient, after touching a patient, and after touching the patient's surroundings (all p < 0.01). Nurses and medical interns achieved consistent and significant increases in hand rub compliance during the entire follow-up period (all p < 0.01). CONCLUSION: Implementing the WHO HH improvement strategy significantly increased HH compliance despite a shortage of water and other resources. Hand rub was accepted as the main HH method in the hospital. HH campaigns in developing settings profit from multimodal strategies, knowledge exchange and utilization of local resources.

Determination of bisphenol a in urine from mother-child pairs-results from the duisburg birth cohort study, Germany.

Bisphenol A (BPA) may alter endocrine functions, and human exposure is widespread. In the Duisburg birth cohort study the influence of several contaminants was examined on the neuropsychological and pubertal development of children. This study reports the biomonitoring results on BPA within the 6-yr follow-up study (children's age 6-8 yr). Total BPA and free (unconjugated) BPA concentrations in 208 urine samples of 104 mother-child pairs were measured. For quality control, total BPA was analyzed by two independent laboratories. BPA was detected in all urine samples, while free BPA was observed above the limit of quantification (LOQ) in only 33 samples. Total BPA concentrations were significantly associated between the two laboratories. BPA concentrations (median; range) tended to be higher in children than in mothers but the difference was not significant. Total BPA levels in children and mothers correlated at low levels but significantly to each other. Multivariate linear regression analysis revealed positive associations between creatinine and the BPA concentrations and a negative association with German nationality (mothers only). Evidence indicates that BPA exposure is omnipresent but levels in mother-child pairs are low. Only small amounts (less than 16%) were detectable as free (unconjugated) BPA. Analytical reliability is high even at such low levels, provided that external contamination is minimized.

Prenatal and early life exposure to polychlorinated dibenzo-p-dioxins, dibenzofurans and biphenyls may influence dehydroepiandrosterone sulfate levels at prepubertal age: results from the Duisburg birth cohort study.

Polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/F) and polychlorinated biphenyls (PCB) are postulated to act as endocrine disrupters. In the ongoing Duisburg birth cohort study, started in 2000-2002, influence of persistent organic pollutants (POP) on child development was monitored. For the first time, associations were reported between prenatal and postnatal PCDD/F and PCB exposures and early endocrinological changes concerning adrenarchal development. PCDD/F and PCB concentrations were measured in blood samples taken in wk 32 of pregnancy and in breast milk using gas chromatography and high-resolution mass spectrometry (GC/HRMS). At the age of 6-7 and 8-9 yr, serum samples were collected from 111 children. The samples were assayed for the sex hormones testosterone, estradiol, dehydroepiandrosterone sulfate (DHEA-S), and 17-OH-progesterone (17-OHP) by using an automated chemiluminescence assay system. Analyses of repeated measurements of DHEA-S serum levels were performed by linear regression analysis using generalized estimating equations (GEE). Linear regression analysis showed a positive association between DHEA-S and breast milk levels of PCDD/F and PCB expressed as toxicity equivalents according to toxicity equivalent factors published by the World Health Organization (WHO) in 2005 (WHO(2005)-TEq) (increase of 29%, geometric mean ratio, GMR: 1.29, 95% CI 1.06-1. 58 per doubling of PCDD/F + PCB WHO(2005)-TEq levels). Results for the association with the WHO(2005)-TEq levels in blood of mothers were in the same direction (increase of 15%, GMR 1.15, 95% CI 0.93-1.42 per doubling of PCDD/F + PCB WHO(2005)-TEq levels), but not significant. Data indicate that PCDD/F and PCB exposure in infancy may influence DHEA-S serum levels in prepubertal children. Increased DHEA-S serum levels are considered to indicate acceleration of the adrenal maturation.

Nonylphenol (NP) exposure in Germany between 1991 and 2021: Urinary biomarker analyses in the German Environmental Specimen Bank (ESB).

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 µg/L in 1991 to 0.70 µg/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 µg/(kg bw*d) in 1991 to 0.04 µg/(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 µg/(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.

Prenatal exposure to endocrine disrupting chemicals is associated with altered DNA methylation in cord blood.

Prenatal exposure to endocrine disrupting chemicals can interfere with development, and has been associated with social-cognitive functioning and adverse health outcomes later in life. Exposure-associated changes of DNA methylation (DNAm) patterns have been suggested as a possible mediator of this relationship. This study investigated whether prenatal low-dose exposure to polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) is associated with altered DNAm patterns across the genome in a Western urban-industrial population. In 142 mother-infant pairs from the Duisburg Birth Cohort Study, PCBs and PCDD/Fs levels were quantified from maternal blood during late pregnancy and associated with DNAm levels in cord blood using the Illumina EPIC beadchip. The epigenome-wide association studies (EWAS) identified 32 significantly differentially methylated positions (DMPs) and eight differentially methylated regions (DMRs) associated with six congeners of PCB and PCDD in females or males (FDRs < 0.05). DMPs and DMRs mapped to genes involved in neurodevelopment, gene regulation, and immune functioning. Weighted gene correlation network analysis (WGCNA) showed 31 co-methylated modules (FDRs < 0.05) associated with one congener of PCDF levels in females. Results of both analytical strategies indicate that prenatal exposure to PCBs and PCDD/Fs is associated with altered DNAm of genes involved in neurodevelopment, gene expression and immune functioning. DNAm and gene expression levels of several of these genes were previously associated with EDC exposure in rodent models. Follow-up studies will clarify whether these epigenetic changes might contribute to the origin for adverse mental and health outcomes.

Prevalence of nickel sensitization and urinary nickel content of children are increased by nickel in ambient air.

In a cross-sectional study performed in 2000, an unexpected positive association between nickel (Ni) in ambient air, urinary Ni content and the prevalence of Ni sensitization in a subgroup of 6-yr-old children living near a steel mill was observed. Between 2005 and 2006, in a different and larger study population, we examined if Ni from ambient air or urinary Ni concentration was related to Ni sensitization in children living next to Ni-emitting steel mills. We studied 749 school beginners living in four Ni-polluted industrial areas of North Rhine-Westphalia, Germany. We assessed Ni in ambient air, Ni in urine from children and mothers, and Ni in tap water, conducted patch tests in children (including the NiSO(4)-dilution test) and collected questionnaire data. Statistics were done by linear and logistic regression analyses, adjusted for covariates. At increased Ni concentration in ambient air (unit of increase: 10 ng/m(3)), urinary Ni concentrations rose in both mothers (9.1%; 95% CI: 6.8-11.4%) and children (2.4%; 95% CI: 0.4-4.4%). The prevalence of Ni sensitization in children was associated with increased Ni from ambient air (unit of increase: 18 ng/m(3); odds ratio 1.28; 95% CI: 1.25-1.32) and urinary Ni concentration (unit of increase: 7.1 µg/L; odds ratio 2.4; 95% CI: 1.20-4.48). Ni in ambient air of areas with Ni-emitting factories contributes to internal Ni exposure in residents via inhalation and, furthermore, is a risk factor for the development of Ni sensitization in children.

Bisphenol A and six other environmental phenols in urine of children and adolescents in Germany - human biomonitoring results of the German Environmental Survey 2014-2017 (GerES V).

Exposure to environmental phenols such as bisphenol A, benzophenones, 2-phenylphenol, triclosan, and triclocarban is of concern, because of their endocrine disrupting properties and broad application in consumer products. The current body burden of the 3-17-year-old population in Germany to these substances was assessed in first-morning void urine samples (N = 515-516) collected within the population-representative German Environmental Survey for Children and Adolescents 2014-2017 (GerES V). Bisphenol A was the most prominent phenol analysed here, ubiquitously found in almost all samples with a geometric mean (GM) concentration of 1.905 µg/L (1.669 µg/gcreatinine) and a maximum (MAX) urinary concentration of 399 µg/L. Benzophenone-3 and benzophenone-1 were quantified in 35% and 41% of the samples. GM was below the limit of quantification (LOQ) for benzophenone-3 and 0.559 µg/L (0.489 µg/gcrea) for benzophenone-1, MAX concentrations were 845 µg/L and 202 µg/L, respectively. In 16% of the samples triclosan was found in quantifiable amounts resulting in a GM below LOQ and a MAX concentration of 801 µg/L. Benzophenone-8, 2-phenylphenol and triclocarban were quantified in none or only 1% of the samples. Benzophenone-1 and -3 concentrations were found to be associated with frequent application of personal care products. A comparison with the previous cycle of the survey, GerES IV (2003-2006), showed a decrease of urinary bisphenol A concentrations, mainly in young children. Despite this decrease, the concentration of bisphenol A exceeded the human biomonitoring (HBM) value HBM-I of 0.1 mg/L in 0.11% of the samples. For triclosan, all urinary concentrations were well below the HBM-I value of 2 mg/L. To minimise environmental health risks, it is therefore necessary to maintain a further declining trend for bisphenol A and continue monitoring the exposure to environmental phenols, as well as to monitor substitutes such as bisphenol F and S.

Alkyl pyrrolidone solvents N-methyl-2-pyrrolidone (NMP) and N-ethyl-2-pyrrolidone (NEP) in urine of children and adolescents in Germany - human biomonitoring results of the German Environmental Survey 2014-2017 (GerESV).

N-methyl-2-pyrrolidone (NMP) and its substitute N-ethyl-2-pyrrolidone (NEP) are aprotic solvents used in many technical applications, but also in carpets, and consumer products such as cleaning agents, and cosmetics. NMP and NEP are classified as reproductive toxicants. As a substance of very high concern (SVHC), NMP is included in the European REACH (Registration, Evaluation, Authorisation of Chemicals) candidate listfor authorisation. NMP and NEP metabolites were measured in more than 2100 urine samples of 3- to 17-year-old children and adolescents, participating in the population-representative German Environmental Survey for Children and Adolescents 2014-2017 (GerESV). The two NMP metabolites 5-hydroxy-N-methyl-2-pyrrolidone (5-HNMP) and 2-hydroxy-N-methylsuccinimide (2-HMSI) could be detected and quantified in all urine samples, and the two NEP metabolites 5-hydroxy-N-ethylpyrrolidone (5-HNEP) and 2-hydroxy-N-ethylsuccinimide (2-HESI) in 32% and 87% of the urine samples. Geometric mean concentrations were 103.1 µg/L (88.21 µg/gcreatinine) for the sum of NMP metabolites and 11.86 µg/L (10.15 µg/gcreatinine) for the sum of NEP metabolites, thus remaining below the current health-based human biomonitoring values. For NMP, highest exposure was found in young children, but exposure pathways could not be revealed. Exposure to NEP was highest in adolescents and participants with low socio-economic status or migration background. Associations to usage of personal care products suggested the choice of products to have a distinct impact on NEP exposure. The presented data can be used by the German Human Biomonitoring Commission to derive new reference values (RV95) for NMP and NEP for children and adolescents in Germany. This will facilitate to recognise changing exposure levels in this population group in Germany.

The European human biomonitoring platform - Design and implementation of a laboratory quality assurance/quality control (QA/QC) programme for selected priority chemicals.

A fundamental objective of the human biomonitoring for Europe initiative (HBM4EU) is to progress toward comparable and robust exposure data for a wide variety of prioritized chemicals in human samples. A programme for Quality Assurance/Quality Control (QA/QC) was designed in HBM4EU with the purpose of creating a network of European laboratories providing comparable analytical data of high quality. Two approaches were chosen for two sets of prioritized chemicals with different timelines: (i) Scheme 1, where interested candidate laboratories participated in multiple rounds of proficiency tests (ii) Scheme 2, where selected expert laboratories participated in three rounds of interlaboratory comparison investigations. In both cases, the results were used to identify laboratories capable of generating consistent and comparable results for sample analysis in the frame of HBM4EU. In total, 84 laboratories from 26 countries were invited to participate in Scheme 1 that covered up to 73 biomarkers from Hexamoll® DINCH, phthalates, bisphenols, per- and polyfluoroalkyl substances, halogenated flame retardants (HFRs), organophosporous flame retardants (OPFRs), polycyclic aromatic hydrocarbons (PAH), cadmium, chromium and aromatic amines. 74 of the participants were successful for at least one biomarker in Scheme 1. Scheme 2 involved 22 biomarkers and successful results were obtained by 2 expert laboratories for arsenic, 5 for acrylamide, 4 for mycotoxins, 2 for pesticides and 2 for UV-filters in skin care products. The QA/QC programme allowed the identification of major difficulties and needs in HBM analysis as well of gaining insight in the analytical capacities of European laboratories. Furthermore, it is the first step towards the establishment of a sustainable European network of HBM laboratories.

Biomarkers, matrices and analytical methods targeting human exposure to chemicals selected for a European human biomonitoring initiative.

The major purpose of human biomonitoring is the mapping and assessment of human exposure to chemicals. The European initiative HBM4EU has prioritized seven substance groups and two metals relevant for human exposure: Phthalates and substitutes (1,2-cyclohexane dicarboxylic acid diisononyl ester, DINCH), bisphenols, per- and polyfluoroalkyl substances (PFASs), halogenated and organophosphorous flame retardants (HFRs and OPFRs), polycyclic aromatic hydrocarbons (PAHs), arylamines, cadmium and chromium. As a first step towards comparable European-wide data, the most suitable biomarkers, human matrices and analytical methods for each substance group or metal were selected from the scientific literature, based on a set of selection criteria. The biomarkers included parent compounds of PFASs and HFRs in serum, of bisphenols and arylamines in urine, metabolites of phthalates, DINCH, OPFRs and PAHs in urine as well as metals in blood and urine, with a preference to measure Cr in erythrocytes representing Cr (VI) exposure. High performance liquid chromatography-tandem mass spectrometry (LC-MS/MS) was the method of choice for bisphenols, PFASs, the HFR hexabromocyclododecane (HBCDD), phenolic HFRs as well as the metabolites of phthalates, DINCH, OPFRs and PAHs in urine. Gas chromatographic (GC) methods were selected for the remaining compounds, e.g. GC-low resolution MS with electron capture negative ionization (ECNI) for HFRs. Both GC-MS and LC-MS/MS were suitable for arylamines. New developments towards increased applications of GC-MS/MS may offer alternatives to GC-MS or LC-MS/MS approaches, e.g. for bisphenols. The metals were best determined by inductively coupled plasma (ICP)-MS, with the particular challenge of avoiding interferences in the Cd determination in urine. The evaluation process revealed research needs towards higher sensitivity and non-invasive sampling as well as a need for more stringent quality assurance/quality control applications and assessments.

A protein interaction node at the neurotransmitter release site: domains of Aczonin/Piccolo, Bassoon, CAST, and rim converge on the N-terminal domain of Munc13-1.

Multidomain scaffolding proteins organize the molecular machinery of neurotransmitter vesicle dynamics during synaptogenesis and synaptic activity. We find that domains of five active zone proteins converge on an interaction node that centers on the N-terminal region of Munc13-1 and includes the zinc-finger domain of Rim1, the C-terminal region of Bassoon, a segment of CAST1/ELKS2, and the third coiled-coil domain (CC3) of either Aczonin/Piccolo or Bassoon. This multidomain complex may constitute a center for the physical and functional integration of the protein machinery at the active zone. An additional connection between Aczonin and Bassoon is mediated by the second coiled-coil domain of Aczonin. Recombinant Aczonin-CC3, expressed in cultured neurons as a green fluorescent protein fusion protein, is targeted to synapses and suppresses vesicle turnover, suggesting involvements in synaptic assembly as well as activity. Our findings show that Aczonin, Bassoon, CAST1, Munc13, and Rim are closely and multiply interconnected, they indicate that Aczonin-CC3 can actively participate in neurotransmitter vesicle dynamics, and they highlight the N-terminal region of Munc13-1 as a hub of protein interactions by adding three new binding partners to its mechanistic potential in the control of synaptic vesicle priming.

Time course of phthalate cumulative risks to male developmental health over a 27-year period: Biomonitoring samples of the German Environmental Specimen Bank.

In several human biomonitoring surveys, changes in the usage patterns of phthalates have come to light, but their influence on the risks associated with combined exposures is insufficiently understood. Based on the largest study to date, the 27-year survey of urinary phthalate metabolite levels in 24-hour urine samples from the German Environmental Specimen Bank, we present a deep analysis of changing phthalate exposures on mixture risks. This analysis adopts the Hazard Index (HI) approach based on the five phthalates DBP, DIBP, BBP, DEHP and DINP. Calculations of the hazard index for each study participant included updated phthalate reference doses for anti-androgenicity (RfDAAs) that take account of new evidence of phthalates' developmental toxicity. The Maximum Cumulative Ratio (MCR) approach was used to establish whether a subject's combined exposure was dominated by one phthalate or was influenced by several phthalates simultaneously. Generally, over the years there was a shift towards lower HIs and higher MCRs, reflecting an increased complexity of the combined exposures. The decade from 1988 to about 1999 was characterised by rather high HIs of between 3 and 7 (95th percentile) which were driven by exposure to DBP and DEHP, often exceeding their single acceptable exposures. Traditional single phthalate risk assessments would have underestimated these risks by up to 50%. From 2006 onwards, no study participant experienced exposures above acceptable levels for a single phthalate, but combined exposures were still in excess of HI = 1. From 2011 onwards most individuals stayed below HI = 1. In interpreting these results, we caution against the use of HI = 1 as an acceptable limit and develop proposals for improved and more realistic mixture risk assessments that take account of co-exposures to other anti-androgenic substances also capable of disrupting the male reproductive system. From this perspective, we regard HIs between 0.1 and 0.2 as more appropriate for evaluating combined phthalate exposures. Assessed against lowered HIs of 0.1 - 0.2, the combined phthalate exposures of most study participants exceeded acceptable levels in all study years, including 2015. Continued monitoring efforts for phthalate combinations are required to provide the basis for appropriate risk management measures.

Time trend of exposure to the phthalate plasticizer substitute DINCH in Germany from 1999 to 2017: Biomonitoring data on young adults from the Environmental Specimen Bank (ESB).

DINCH (cyclohexane-1,2-dicarboxylic acid-diisononyl ester) is a phthalate plasticizer substitute introduced into the market in 2002. It is increasingly used especially in the production of toys, food contact materials and medical devices. In this measurement campaign on 24-h urine samples of young adults (20-29 years) from the German Environmental Specimen Bank (ESB) collected in 2010, 2011, 2013, 2015 and 2017 (in total 300 samples, 60 samples/year) we analyzed three specific, oxidized DINCH metabolites (OH-MINCH: cyclohexane-1,2-dicarboxylic acid-mono(hydroxy-isononyl) ester; cx-MINCH: cyclohexane-1,2-dicarboxylic acid-mono(carboxy-isooctyl) ester, oxo-MINCH: cyclohexane-1,2-dicarboxylic acid-mono(oxo-isononyl) ester). We merged these data with earlier data of the ESB from the years 1999-2012 and are now able to report levels and time trends of internal DINCH exposure from 1999 to 2017. After first detections of the major oxidized DINCH metabolite OH-MINCH in 2006 (6.7%) detection rates rapidly increased to 43.3% in 2009, 80% in 2010 and 98.3% in 2011 and 2012. From the year 2013 on we could detect OH-MINCH in every urine sample analyzed. The median concentrations of OH-MINCH rapidly increased from 0.15 µg/L in 2010 to twice the concentration in 2011 (0.31 µg/L) with further increases in 2013 (0.37 µg/L), 2015 (0.59 µg/L) and 2017 (0.70 µg/L). Similar increases, albeit at lower detection rates and concentration levels, could be observed for cx-MINCH and oxo-MINCH. All metabolites strongly correlate with each other. For the ESB study population, DINCH exposures are still far below health based guidance values such as the German Human Biomonitoring Value (HBM-I; 4,500 µg/L for the sum of OH-MINCH and cx-MINCH) or the tolerable daily intake (TDI) of EFSA (1 mg/kg bw/d). The median daily DINCH intake (DI) calculated for 2017 was 0.23 µg/kg bw/d, thus 4,310-times lower than the TDI. The maximum DI calculated for one individual in 2012 (42.60 µg/kg bw/d) was a factor of more than 20 below the TDI. The ongoing increase in DINCH exposure needs to be closely monitored in the future, including populations with potentially higher exposures such as children. This close monitoring will enable timely exposure and risk reduction measures if exposures reached critical levels, or if new toxicological data lead to lower health based guidance values. DINCH belongs to the European Human Biomonitoring Initiative (HBM4EU) priority substances for which policy relevant questions still have to be answered.