Preliminary assessment of general population exposure to perfluoroalkyl substances through diet in Greece.

Food and drinking water intake are the major routes of exposure to perfluoroalkyl substances (PFASs) for humans. In this study an initial oral exposure assessment of the non-occupationally exposed general Greek population to PFASs is presented. Levels of PFOA and PFOS determined in the present study in 128 food items from the Greek market and previously published analytical results of 43 water samples and 76 egg samples from Greece were combined with food availability data of the DAFNE-ANEMOS database for the calculation of oral intake of PFASs. Fish form the food group with the highest concentration in both PFOA and PFOS. For the general Greek population the estimated average daily intake in PFOA and PFOS when applying the lowerbound mean concentrations in food and drinking water samples is 0.49 and 0.91 ng kg-1 body weight (b.w.) respectively. The main contributor to oral PFAS intake is fish. A pharmacokinetic model is applied to estimate total intake from blood serum levels reported previously and the predicted values are in agreement with lowerbound estimated values. Weekly intake estimated values are below the tolerable weekly intake recently proposed by EFSA.

Biomarkers of exposure in environment-wide association studies - Opportunities to decode the exposome using human biomonitoring data.

BACKGROUND: The European Union's 7th Framework Programme (EU's FP7) project HEALS - Health and Environment-wide Associations based on Large Population Surveys - aims a refinement of the methodology to elucidate the human exposome. Human biomonitoring (HBM) provides a valuable tool for understanding the magnitude of human exposure from all pathways and sources. However, availability of specific biomarkers of exposure (BoE) is limited. OBJECTIVES: The objective was to summarize the availability of BoEs for a broad range of environmental stressors and exposure determinants and corresponding reference and exposure limit values and biomonitoring equivalents useful for unraveling the exposome using the framework of environment-wide association studies (EWAS). METHODS: In a face-to-face group discussion, scope, content, and structure of the HEALS deliverable "Guidelines for appropriate BoE selection for EWAS studies" were determined. An expert-driven, distributed, narrative review process involving around 30 individuals of the HEALS consortium made it possible to include extensive information targeted towards the specific characteristics of various environmental stressors and exposure determinants. From the resulting 265 page report, targeted information about BoE, corresponding reference values (e.g., 95th percentile or measures of central tendency), exposure limit values (e.g., the German HBM I and II values) and biomonitoring equivalents (BEs) were summarized and updated. RESULTS: 64 individual biological, chemical, physical, psychological and social environmental stressors or exposure determinants were included to fulfil the requirements of EWAS. The list of available BoEs is extensive with a number of 135; however, 12 of the stressors and exposure determinants considered do not leave any measurable specific substance in accessible body specimens. Opportunities to estimate the internal exposure stressors not (yet) detectable in human specimens were discussed. CONCLUSIONS: Data about internal exposures are useful to decode the exposome. The paper provides extensive information for EWAS. Information included serves as a guideline - snapshot in time without any claim to comprehensiveness - to interpret HBM data and offers opportunities to collect information about the internal exposure of stressors if no specific BoE is available.

Systematic investigation of organochlorine pesticides and polychlorinated biphenyls blood levels in Greek children from the Rhea birth cohort suggests historical exposure to DDT and through diet to DDE.

The blood levels of organochlorine pesticides (OCPs) and polychlorinated biphenyls (PCBs) have been thoroughly investigated in Greek children from the Rhea birth cohort study. This investigation aimed to assess exposure levels, explore their possible relationship with children's age and sex, and indicate potential sources of exposure. Exposure patterns and common sources of PCBs and OCPs were analyzed using bivariate and multivariate statistics. A total of 947 blood samples from study participants were analyzed for OCP and PCB exposure, with 375 samples collected at 4 years old, 239 at 6.5 years old, and 333 at 11 years old. Elevated levels of DDE were observed in 6.5-year-old children compared to corresponding levels in other European countries. Higher levels of DDE were found in 4-year-old children, with the lowest concentrations in the 11-year-old group. The DDT/DDE ratio was consistently less than 1 among all the examined subjects. These results indicate exposure to DDT and DDE both in utero and through breastfeeding and dietary intake. For the entire cohort population, the highest concentration was determined for PCB 28, followed by PCBs 138, 153, and 180. The sum of the six indicator PCBs implied low exposure levels for the majority of the cohort population. Spearman correlations revealed strong associations between PCBs and OCPs, while principal component analysis identified two different groupings of exposure. DDE exhibited a correlation with a series of PCBs (153, 156, 163, 180), indicating a combined OCP-PCB source, and an anticorrelation with others (52, 28, 101), implying a separate and competing source.

An effective and low cost carbon based clean-up method for PCDD/Fs and PCBs analysis in food.

Sample preparation is of critical importance in dioxin analysis of food and feed samples. It is a complex procedure that includes lipid extraction followed by the application of chromatographic separation techniques, aiming in removing undesirable interferences from the matrix. The separation of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from polychlorinated biphenyls (PCBs) is achieved by carbon-based materials which should have high fat capacity in order to be suitable for lipid-containing matrices. Automated methods are available but due to high cost and use of high amounts of solvents, manual methods are also applied. An active carbon material (Carbosphere) with high fat capacity that has been used in the past for manual methods is no longer commercially available. The present study assesses an alternative active carbon material, FU 4652, that can be used for the separation of PCDD/Fs and non-ortho PCBs. Mono-ortho and 6 non-dioxin-like PCBs are also analyzed. The method was validated according to the analytical criteria set in EU regulations 589/2014 and 709/2014. Control samples analyzed for the evaluation of the above material were olive oil reference samples spiked with PCDD/Fs and dioxin-like PCBs at two concentration levels. The new method was tested successfully on food samples of interlaboratory trials organized in previous years. Farmed fish samples collected within national surveillance programs for the years 2016-2017 were analyzed with the method developed. The results obtained indicate that the FU 4652 carbon sorbent has high fat capacity and is capable of separating congeners with good recoveries.