Human urinary arsenic species, associated exposure determinants and potential health risks assessed in the HBM4EU Aligned Studies

The European Joint Programme HBM4EU coordinated and advanced human biomonitoring (HBM) in Europe in order to provide science-based evidence for chemical policy development and improve chemical management. Arsenic (As) was selected as a priority substance under the HBM4EU initiative for which open, policy relevant questions like the status of exposure had to be answered. Internal exposure to inorganic arsenic (iAs), measured as Toxic Relevant Arsenic (TRA) (the sum of As(III), As(V), MMA, DMA) in urine samples of teenagers differed among the sampling sites (BEA (Spain) > Riksmaten adolescents (Sweden), ESTEBAN (France) > FLEHS IV (Belgium), SLO CRP (Slovenia)) with geometric means between 3.84 and 8.47 μg/L. The ratio TRA to TRA + arsenobetaine or the ratio TRA to total arsenic varied between 0.22 and 0.49. Main exposure determinants for TRA were the consumption of rice and seafood. When all studies were combined, Pearson correlation analysis showed significant associations between all considered As species. Higher concentrations of DMA, quantitatively a major constituent of TRA, were found with increasing arsenobetaine concentrations, a marker for organic As intake, e.g. through seafood, indicating that other sources of DMA than metabolism of inorganic As exist, e.g. direct intake of DMA or via the intake of arsenosugars or -lipids. Given the lower toxicity of DMA(V) versus iAs, estimating the amount of DMA not originating from iAs, or normalizing TRA for arsenobetaine intake could be useful for estimating iAs exposure and risk. Comparing urinary TRA concentrations with formerly derived biomonitoring equivalent (BE) for non-carcinogenic effects (6.4 μg/L) clearly shows that all 95th percentile exposure values in the different studies exceeded this BE. This together with the fact that cancer risk may not be excluded even at lower iAs levels, suggests a possible health concern for the general population of Europe.

Exposure to Phthalates in European Children, Adolescents and Adults since 2005: A Harmonized Approach Based on Existing HBM Data in the HBM4EU Initiative

Phthalates are mainly used as plasticizers and are associated inter alia with adverse effects on reproductive functions. While more and more national programs in Europe have started monitoring internal exposure to phthalates and its substitute 1,2-Cyclohexanedicarboxylic acid (DINCH), the comparability of results from such existing human biomonitoring (HBM) studies across Europe is challenging. They differ widely in time periods, study samples, degree of geographical coverage, design, analytical methodology, biomarker selection, and analytical quality assurance level. The HBM4EU initiative has gathered existing HBM data of 29 studies from participating countries, covering all European regions and Israel. The data were prepared and aggregated by a harmonized procedure with the aim to describe-as comparably as possible-the EU-wide general population's internal exposure to phthalates from the years 2005 to 2019. Most data were available from Northern (up to 6 studies and up to 13 time points), Western (11; 19), and Eastern Europe (9; 12), e.g., allowing for the investigation of time patterns. While the bandwidth of exposure was generally similar, we still observed regional differences for Butyl benzyl phthalate (BBzP), Di(2-ethylhexyl) phthalate (DEHP), Di-isononyl phthalate (DiNP), and Di-isobutyl phthalate (DiBP) with pronounced decreases over time in Northern and Western Europe, and to a lesser degree in Eastern Europe. Differences between age groups were visible for Di-n-butyl phthalate (DnBP), where children (3 to 5-year olds and 6 to 11-year olds) had lower urinary concentrations than adolescents (12 to 19-year-olds), who in turn had lower urinary concentrations than adults (20 to 39-year-olds). This study is a step towards making internal exposures to phthalates comparable across countries, although standardized data were not available, targeting European data sets harmonized with respect to data formatting and calculation of aggregated data (such as developed within HBM4EU), and highlights further suggestions for improved harmonization in future studies.

Exposure to bisphenol A in European women from 2007 to 2014 using human biomonitoring data - The European Joint Programme HBM4EU

BACKGROUND

Bisphenol A (BPA; or 4,4'-isopropylidenediphenol) is an endocrine disrupting chemical. It was widely used in a variety of plastic-based manufactured products for several years. The European Food Safety Authority (EFSA) recently reduced the Tolerable Daily Intake (TDI) for BPA by 20,000 times due to concerns about immune-toxicity.

OBJECTIVE

We used human biomonitoring (HBM) data to investigate the general level of BPA exposure from 2007 to 2014 of European women aged 18-73 years (n = 4,226) and its determinants.

METHODS

Fifteen studies from 12 countries (Austria, Belgium, Denmark, France, Germany, Greece, Israel, Luxembourg, Slovenia, Spain, Sweden, and the United Kingdom) were included in the BPA Study protocol developed within the European Joint Programme HBM4EU. Seventy variables related to the BPA exposure were collected through a rigorous post-harmonization process. Linear mixed regression models were used to investigate the determinants of total urine BPA in the combined population.

RESULTS

Total BPA was quantified in 85-100 % of women in 14 out of 15 contributing studies. Only the Austrian PBAT study (Western Europe), which had a limit of quantification 2.5 to 25-fold higher than the other studies (LOQ=2.5 µg/L), found total BPA in less than 5 % of the urine samples analyzed. The geometric mean (GM) of total urine BPA ranged from 0.77 to 2.47 µg/L among the contributing studies. The lowest GM of total BPA was observed in France (Western Europe) from the ELFE subset (GM=0.77 µg/L (0.98 µg/g creatinine), n = 1741), and the highest levels were found in Belgium (Western Europe) and Greece (Southern Europe), from DEMOCOPHES (GM=2.47 µg/L (2.26 µg/g creatinine), n = 129) and HELIX-RHEA (GM=2.47 µg/L (2.44 µg/g creatinine), n = 194) subsets, respectively. One hundred percent of women in 14 out of 15 data collections in this study exceeded the health-based human biomonitoring guidance value for the general population (HBM-GVGenPop) of 0.0115 µg total BPA/L urine derived from the updated EFSA's BPA TDI. Variables related to the measurement of total urine BPA and those related to the main socio-demographic characteristics (age, height, weight, education, smoking status) were collected in almost all studies, while several variables related to BPA exposure factors were not gathered in most of the original studies (consumption of beverages contained in plastic bottles, consumption of canned food or beverages, consumption of food in contact with plastic packaging, use of plastic film or plastic containers for food, having a plastic floor covering in the house, use of thermal paper…). No clear determinants of total urine BPA concentrations among European women were found. A broader range of data planned for collection in the original questionnaires of the contributing studies would have resulted in a more thorough investigation of the determinants of BPA exposure in European women.

CONCLUSION

This study highlights the urgent need for action to further reduce exposure to BPA to protect the population, as is already the case in the European Union. The study also underscores the importance of pre-harmonizing HBM design and data for producing comparable data and interpretable results at a European-wide level, and to increase HBM uptake by regulatory agencies.