This open access book reviews the trends of persistent organic pollutants (POPs) in human milk and discusses the main findings of five global surveys that were coordinated by the World Health ...Organization (WHO) and the United Nations Environment Programme (UNEP) from 2000 to 2019. Human milk was selected as core matrix for human exposure under the Global Monitoring Plan for effectiveness evaluation of the Stockholm Convention on Persistent Organic Pollutants. Milk from well-defined groups of mothers was collected and mixed to form a representative sample per country. Datasets collected represent the largest global human tissues survey with a harmonized protocol, carried out in a uniform format for more than two decades. Altogether 69 countries participated in these studies between 2000 and 2015, and more than 40 countries participated in the study from 2016 to 2019. Divided into 5 parts, the book offers an authoritative overview of human milk biomonitoring; collates the harmonized sampling requirements and analytical methods for the identification and quantification of contaminants in human milk; examines the results of the WHO/UNEP-coordinated exposure studies, including the identification of selected chlorinated pesticides, dioxin-like compounds, industrial chemicals like polychlorinated biphenyls (PCB) and chlorinated paraffins, polybrominated POPs and PFAS, among others; and traces geographic, temporal and cross-substance trends and correlations, and human health risks. The book finishes by providing the reader with the summary of the main findings and outlook from these studies, in which the comparison of concentrations found for the wide range of POPs listed in the Stockholm Convention allowed the identification of possible needs for actions and follow-ups in different countries/regions. This book contributes to the understanding of exposure to hazardous chemicals and pollution as addressed by the UN Sustainable Development Goals on Good Health and Well-being (SDG 3) and will appeal to environmental and analytical chemists, researchers, professionals, and policymakers interested in learning more about contaminants in human milk. Given its breadth, this book will also appeal to a broader audience interested in maternal and child health.
Polychlorinated dibenzo‐p‐dioxins (PCDD) and dibenzofurans (PCDF), together simplified termed “dioxins”, polychlorinated biphenyls (PCB), polybrominated diphenylethers (PBDE) and organochlorine ...pesticides constitute lipophilic, persistent organic pollutants that bioaccumulate in the food chain and consequently can be found in humans at considerable concentrations. During the past 30 years our institute analyzed far more than 2000 individual human milk samples for organochlorine pesticides and PCB and over 1000 specimens for PCDD/PCDF. The results of these analyses provide an overview and reliable basis as to contamination of human milk with these compounds, their correlations among each other, the temporal trend of exposure through breastfeeding and the predominant parameters that influence the maternal body burden. It was found that the levels of most persistent organohalogen compounds in human milk decreased significantly over the past three decades and equally did their exposure through breastfeeding. Exceptions are PBDE, which are still extensively used as flame‐retardants. PBDE levels in milk samples collected in the early 2000s are approximately 60% higher compared to specimens sampled 10 years before. Moreover, in contrast to PCB, PBDE show no significant correlation with PCDD/PCDF in human milk, which might be interpreted as an indication for another mode of human exposure.
The transfer of the perfluoroalkyl acids (PFAAs) perfluorobutanesulfonate (PFBS), perfluorohexanesulfonate (PFHxS), perfluorooctanesulfonate (PFOS), and perfluorooctanoate (PFOA) from feed into ...tissue and milk of dairy cows was investigated. Holstein cows (n = 6) were fed a PFAA-contaminated feed for 28 days. After the PFAA-feeding period, three cows were slaughtered while the others were fed PFAA-free feed for another 21 days (depuration period). For PFAA analysis plasma, liver, kidney, and muscle tissue, urine, and milk were sampled and analyzed using high-performance liquid chromatography (HPLC) with tandem mass spectrometry (MS/MS). The average daily intake of dairy cows was 3.4 ± 0.7, 4.6 ± 1.0, 7.6 ± 3.7 and 2.0 ± 1.2 μg/kg body weight (bw) for PFBS, PFHxS, PFOS, and PFOA, respectively. Overall, PFBS, PFHxS, PFOS, and PFOA showed different kinetics in dairy cows. In plasma, concentrations of PFBS (mean = 1.2 ± 0.8 μg/L) and PFOA (mean = 8.5 ± 5.7 μg/L) were low, whereas PFHxS and PFOS continuously increased during the PFAA-feeding period up to maximal concentrations of 419 ± 172 and 1903 ± 525 μg/L, respectively. PFOS in plasma remained constantly high during the depuration period. PFOS levels were highest in liver, followed by kidney, without significant differences between feeding periods. The highest PFHxS levels were detected in liver and kidney of cows slaughtered on day 29 (61 ± 24 and 98 ± 31 μg/kg wet weight (ww)). The lowest PFAA levels were detected in muscle tissue. At the end of the feeding study, cumulative secretion in milk was determined for PFOS (14 ± 3.6%) and PFHxS (2.5 ± 0.2%). The other two chemicals were barely secreted into milk: PFBS (0.01 ± 0.02%) and PFOA (0.1 ± 0.06%). Overall, the kinetics of PFOA were similar to those of PFBS and substantially differed from those of PFHxS and PFOS. The very low concentration of PFBS in plasma and milk, the relatively high urinary excretion, and only traces of PFBS in liver (0.3 ± 0.3 μg/kg ww) and kidney (1.0 ± 0.3 μg/kg ww) support the conclusion that PFBS does not accumulate in the body of dairy cows.
Dioxin-like polychlorinated biphenyls (dl-PCBs) as well as polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs) are a major concern for food safety, especially in fat-containing foods ...of animal origin, such as milk. Due to the lipophilic character of PCDD/Fs and PCBs, it is of special interest to explore whether the metabolic state of high-yielding cows influences the transfer rates into milk. Five German Holstein cows were orally exposed to a mixture of 17 PCDD/Fs, 12 dl-PCBs, and 6 non-dioxin-like PCBs (ndl-PCBs) for two dosing periods of 28 days each. The first period covered the negative energy balance (NEB) after calving, while the second period addressed the positive energy balance (PEB) in late lactation. Each dosing period was followed by a depuration period of around 100 days. During the NEB phase, the transfer rates of 14 PCDD/Fs and 7 dl-PCBs quantified were significantly (p ≤ 0.1) higher compared to the PEB phase, indicating an influence of the metabolic state on the transfer. Furthermore, the congener-specific transfer rates (0.3–39%) were in the range of the results from former studies. This indicates that the milk yield of the exposed cows is not the only determining factor for the transfer of these congeners into milk.
UVB radiation-induced signaling in mammalian cells involves two major pathways: one that is initiated through the generation of DNA photoproducts in the nucleus and a second one that occurs ...independently of DNA damage and is characterized by cell surface receptor activation. The chromophore for the latter one has been unknown. Here, we report that the UVB response involves tryptophan as a chromophore. We show that through the intracellular generation of photoproducts, such as the arylhydrocarbon receptor (AhR) ligand 6-formylindolo3,2-bcarbazole, signaling events are initiated, which are transferred to the nucleus and the cell membrane via activation of the cytoplasmatic AhR. Specifically, AhR activation by UVB leads to (i) transcriptional induction of cytochrome P450 1A1 and (ii) EGF receptor internalization with activation of the EGF receptor downstream target ERK1/2 and subsequent induction of cyclooxygenase-2. The role of the AhR in the UVB stress response was confirmed in vivo by studies employing AhR KO mice.
The aims of this introductory article are to survey and critically evaluate the concepts and approaches that have been used to assess amino acid adequacy and to hypothesize about possible future ...directions of research. The issue in question is extensive, consequently this article will be limited to: 1) definitions of amino acid requirements; 2) available techniques to assess amino acid requirements; 3) actual recommendations for healthy adults; 4) factors influencing requirements; and 5) requirements in acute and chronic wasting diseases. Recommendations for amino acid intakes for healthy adults were proposed by the FAO/WHO expert committee in 2001. They have not yet been published. The major factors affecting amino acid requirements are the stage of development, reproductive state, environmental factors, digestibility of dietary proteins, genotype of the individual, and pathological conditions. Remarkably, there are no conclusive data relative to changes in requirements induced by infection, injury, trauma, and renal or liver failure. Future research using modern methods to evaluate requirements must thus receive a high priority. Wasting diseases are associated with deficiencies and imbalances of particular amino acids causing specific changes in requirements. Consequently, a new approach has been used to categorize amino acids as conditionally indispensable according to their functional and physiological properties. Kinetic measurements of plasma amino acids might help to estimate qualitative requirements. Measurement of tissue intracellular free amino acid deficiencies or excesses is another method to estimate qualitative requirements. Based on these measurements tentative values for conditionally indispensable amino acids during disease are given in the article.
The quality of exposure assessment is a major determinant of the overall quality of any environmental epidemiology study. The use of biomonitoring as a tool for assessing exposure to ubiquitous ...chemicals with short physiologic half-lives began relatively recently. These chemicals present several challenges, including their presence in analytical laboratories and sampling equipment, difficulty in establishing temporal order in cross-sectional studies, short- and long-term variability in exposures and biomarker concentrations, and a paucity of information on the number of measurements required for proper exposure classification. To date, the scientific community has not developed a set of systematic guidelines for designing, implementing and interpreting studies of short-lived chemicals that use biomonitoring as the exposure metric or for evaluating the quality of this type of research for WOE assessments or for peer review of grants or publications. We describe key issues that affect epidemiology studies using biomonitoring data on short-lived chemicals and propose a systematic instrument – the Biomonitoring, Environmental Epidemiology, and Short-lived Chemicals (BEES-C) instrument – for evaluating the quality of research proposals and studies that incorporate biomonitoring data on short-lived chemicals. Quality criteria for three areas considered fundamental to the evaluation of epidemiology studies that include biological measurements of short-lived chemicals are described: 1) biomarker selection and measurement, 2) study design and execution, and 3) general epidemiological study design considerations. We recognize that the development of an evaluative tool such as BEES-C is neither simple nor non-controversial. We hope and anticipate that the instrument will initiate further discussion/debate on this topic.
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•A tool to evaluate research on biomonitoring of short-lived chemicals is needed.•We developed the Biomonitoring, Environmental Epi, and Short-Lived Chemicals instrument.•The instrument addresses biomarker selection, measurement, study design and execution.•Τhe goal is to improve study design and weight of evidence assessment.
This study presents a comprehensive two-dimensional gas chromatography with negative chemical ionization quadrupole time-of-flight mass spectrometry (GC × GC–NCI–QTOF/MS) method, which allows for a ...precise chromatographic separation of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs). A new reversed-phase column setup was used, which allows for more accurate separation of MCCPs compared to known GC × GC methods. In a pilot study, 25 freshwater fish samples were analyzed with this method to characterize chlorinated paraffin (CP) compositions. The CP composition was similar in the samples, an observation that is important for the development of a suitable routine method. MCCP contamination was considerably higher than SCCP contamination, with concentrations of 1.3–410 ng/g of wet weight and 0.67–6.5 ng/g of wet weight, respectively. These results were compared to those obtained using a second method, direct injection–atmospheric pressure chemical ionization (APCI)–Orbitrap/mass spectrometry (MS). GC × GC separation was considered to be advantageous for accurate quantification of CP contamination.
Microplastics are anthropogenic contaminants which have been found in oceans, lakes and rivers. Investigations focusing on drinking water are rare and studies have mainly been using micro-Fourier ...Transform Infrared Spectroscopy (μ-FT-IR). A major limitation of this technique is its inability to detect particles smaller than 20 μm. However, micro-Raman spectroscopy is capable of detecting even smaller particle sizes. Therefore, we show that this technique, which was used in this study, is particularly useful in detecting microplastics in drinking water where particle sizes are in the low micrometer range. In our study, we compared the results from drinking water distributed in plastic bottles, glass bottles and beverage cartons.
We tested the microplastic content of water from 22 different returnable and single-use plastic bottles, 3 beverage cartons and 9 glass bottles obtained from grocery stores in Germany. Small (–50-500 μm) and very small (1–50 μm) microplastic fragments were found in every type of water. Interestingly, almost 80% of all microplastic particles found had a particle size between 5 and 20 μm and were therefore not detectable by the analytical techniques used in previous studies. The average microplastics content was 118 ± 88 particles/l in returnable, but only 14 ± 14 particles/l in single-use plastic bottles. The microplastics content in the beverage cartons was only 11 ± 8 particles/l. Contrary to our assumptions we found high amounts of plastic particles in some of the glass bottled waters (range 0–253 particles/l, mean 50 ± 52 particles/l). A statistically significant difference from the blank value (14 ± 13) to the investigated packaging types could only be shown comparing to the returnable bottles (p < 0.05).
Most of the particles in water from returnable plastic bottles were identified as consisting of polyester (primary polyethylene terephthalate PET, 84%) and polypropylene (PP; 7%). This is not surprising since the bottles are made of PET and the caps are made of PP. In water from single-use plastic bottles only a few micro-PET-particles have been found. In the water from beverage cartons and also from glass bottles, microplastic particles other than PET were found, for example polyethylene or polyolefins. This can be explained by the fact that beverage cartons are coated with polyethylene foils and caps are treated with lubricants. Therefore, these findings indicate that the packaging itself may release microparticles. The main fraction of the microplastic particles identified are of very small size with dimensions less than 20 μm, which is not detectable with the μ-FT-IR technique used in previous studies.
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•38 mineral waters were analyzed for microplastics by means of μ-Raman spectroscopy.•Microplastics were found in every type of water, almost 80% are sized between 5 and 20 μm.•Statistically significant difference from blank value could only be proven towards returnable bottles.•The found particles correlated with the materials the bottles/cartons were made of.•This indicates that plastic packaging emit microparticles, ingested directly by consumers.
The EFSA Panel on Food Additive and Flavourings (FAF Panel) provides a scientific opinion on the safety of soy leghemoglobin from genetically modified Komagataella phaffii as a food additive in ...accordance with Regulation (EC) No 1331/2008. The proposed food additive, LegH Prep, is intended to be used as a colour in meat analogue products. The yeast Komagataella phaffii strain MXY0541 has been genetically modified to produce soy leghemoglobin; the safety of the genetic modification is under assessment by the EFSA GMO Panel (EFSA‐GMO‐NL‐2019‐162). The amount of haem iron provided by soy leghemoglobin from its proposed uses in meat analogue products is comparable to that provided by similar amounts of different types of meat. The exposure to iron from the proposed food additive, both at the mean and 95th percentile exposure, will be below the ‘safe levels of intake’ established by the NDA Panel for all population groups. Considering that the components of the proposed food additive will be digested to small peptide, amino acids and haem B; the recipient (non GM) strain qualifies for qualified presumption of safety status; no genotoxicity concern has been identified and no adverse effects have been identified at the highest dose tested in the available toxicological studies, the Panel concluded that there was no need to set a numerical acceptable daily intake (ADI) and that the food additive does not raise a safety concern at the proposed use in food category 12.9 and maximum use level. The Panel concluded that the use of soy leghemoglobin from genetically modified Komagataella phaffii MXY0541 as a new food additive does not raise a safety concern at the proposed use and use level. This safety evaluation of the proposed food additive remains provisional subject to the ongoing safety assessment of the genetic modification of the production strain by the GMO Panel (EFSA‐GMO‐NL‐2019‐162).
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