Free-range eggs dioxin contamination assessment: comparison between a simple model and in situ measurements to determine a maximum egg frequency consumption

Dioxins (polychlorinated dibenzodioxins - PCDDs) and furans (polychlorinated dibenzofurans - PCDFs), are a family of aromatic organochlorine molecules whose primary origin of their emission is industrial processes requiring a combustion process. These compounds are very lipophilic, stable and not very biodegradable. These persistent organic pollutants accumulate in fatty tissue. For this reason, food is one of the main source of exposure to PCDD/Fs in our daily environment. Following a large PCDD/Fs soil contamination in Lausanne (Switzerland), a first report evaluated the risk of different exposure scenarios. Poultry houses on contaminated soil represent a risk of contamination by ingestion of PCDD/Fs contaminated eggs. Chickens peck on contaminated land ingest soil. The PCDD/Fs absorbed are found in their fat mass and are eliminated through the eggs. The objective of the study was to evaluate the expected concentrations in eggs as a function of the concentrations in the soil and express recommendation on the frequency of ingestion to remain below the acceptable daily intake. We fitted a PCDD/Fs toxicokinetic model in hens to evaluate the sensitivity of the different parameters. In order to validate the model, we sampled eggs and soil from five chicken houses in the contaminated area. The PCDD/Fs in eggs were extracted by liquid-liquid extraction and quantified by gas chromatography high resolution mass spectrometry. The PCDD/Fs from the soil were extracted using an Accelerated Solvent Extraction and then quantify by gas chromatography high resolution mass spectrometry. The results from the model were compared to the measured concentrations. The model is conservative since there is a tendency to overestimate the real concentrations. A rapid elimination phase during the first days is followed by first order kinetics. Overall, the half-life is 50 days. After 200 days, an equilibrium is reached and the concentrations in the eggs are stable. The parameters that influence the concentrations measured in the eggs are: the soil concentration, the geophagy (amount of soil ingested by the hen during pecking), the age of the hen (or its duration on the contaminated soil) and the egg laying efficiency. The geophagy parameter is the most difficult to predict. In order to limit health risks, we would recommend avoiding eggs from hens if they are pecking on soil above 50 ng Toxic Equivalent (TEQ)/kg soil. Below this concentration, it is recommended to ensure a good vegetation cover to limit geophagy and depending on the soil concentration to reduce the frequency of egg consumption

Brominated Flame Retardants – Endocrine-Disrupting Chemicals in the Swiss Environment

Brominated flame retardants (BFR) are additives used to protect plastic materials and textiles against ignition. As some widely used BFR have chemical structures similar to well known endocrine disruptors such as polychlorinated biphenyls (PCB) or bisphenol A, adverse effects were also presumed for BFR. When the NRP50 programme started in 2001, the sparse knowledge on environmental behavior and toxicology of BFR did not allow a proper assessment of the risks associated with the widespread use of these chemicals. Therefore, we proposed to address questions such as the exposure of animals and humans, temporal trends in the environment as well as transformation and transport processes of BFR. Concentrations of BFR in wildlife and humans in Switzerland today pose no serious concerns for negative health effects according to the current knowledge on the toxicity of BFR. However, negative health effects cannot be ruled out in the future, since some BFR persist in the environment and their concentrations in freshwater lake sediments are increasing rapidly. The development of environmentally safe alternatives to these chemicals will be an important issue for the future

Persistent organic pollutants in tissues of the white-blooded Antarctic fish Champsocephalus gunnari and Chaenocephalus aceratus

The global occurrence of persistent organic pollutants (POPs) continuously contributes to their accumulation also in remote areas such as the Antarctic Ocean. Antarctic fish , which hold high trophic positions but appear to possess low endogenous elimination rates for chemicals, are expected to bioaccumulate POPs with rising anthropogenic pollution. Using a chemical-analytical method, we measured concentrations of PCBs, PBDEs, HCBs, HCH and DDTs and determined toxic equivalents (TEQs) and bioanalytical equivalents (BEQs) in muscle and ovaries of Antarctic icefish caught in the Southern Ocean around Elephant Island. We used two species with different feeding habits and trophic web positions: the planktivorous Champsocephalus gunnari and the piscivorous Chaenocephalus aceratus . Our results revealed higher contaminant levels in ovary than in muscle tissues of both species. Most analytes concentrations and the TEQs (0.2-0.5) and BEQs (0.2) were lower as in temperate species. Comparison with literature data points to higher PCB (20-22 ng g(-1) lipid weight (lw)) and DDT (7 19.5 ng g(-1) lw) concentrations than those measured in icefish in the 90's. For the other contaminants, we could not identify temporal trends. We found a higher bioaccumulation of contaminants, particularly HCB and DDTs, in C. aceratus (6.2 & 19.5 ng g(-1) lw, respectively) than in C. gunnari (3.8 & 7.0 ng g(-1) lw, respectively). However, there was no general species-specific accumulation pattern of the different toxicant classes between the two icefish. Thus, the expected link between contaminant burdens of C aceratus and C gunnari and their ecological traits was only weakly supported for these species

The Cutaneous Lesions of Dioxin Exposure: Lessons from the Poisoning of Victor Yushchenko

Several million people are exposed to dioxin and dioxin-like compounds, primarily through food consumption. Skin lesions historically called "chloracne” are the most specific sign of abnormal dioxin exposure and classically used as a key marker in humans. We followed for 5 years a man who had been exposed to the most toxic dioxin, 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), at a single oral dose of 5 million-fold more than the accepted daily exposure in the general population. We adopted a molecular medicine approach, aimed at identifying appropriate therapy. Skin lesions, which progressively covered up to 40% of the body surface, were found to be hamartomas, which developed parallel to a complete and sustained involution of sebaceous glands, with concurrent transcriptomic alterations pointing to the inhibition of lipid metabolism and the involvement of bone morphogenetic proteins signaling. Hamartomas created a new compartment that concentrated TCDD up to 10-fold compared with serum and strongly expressed the TCDD-metabolizing enzyme cytochrome P450 1A1, thus representing a potentially significant source of enzymatic activity, which may add to the xenobiotic metabolism potential of the classical organs such as the liver. This historical case provides a unique set of data on the human tissue response to dioxin for the identification of new markers of exposure in human populations. The herein discovered adaptive cutaneous response to TCDD also points to the potential role of the skin in the metabolism of food xenobiotic

Evolution of chlorinated paraffin and olefin fingerprints in sewage sludge from 1993 to 2020 of a Swiss municipal wastewater treatment plant

Exposure of humans to chlorinated paraffins (CPs) and chlorinated olefins (COs) can occur via contact with CP-containing plastic materials. Such plastic materials can contain short-chain CPs (SCCPs), which are regulated as persistent organic pollutants (POPs) under the Stockholm Convention since 2017. Municipal wastewater treatment plants (WWTP) collect effluents of thousands of households and their sludge is a marker for CP exposure. We investigated digested sewage sludge collected in the years 1993, 2002, 2007, 2012, and 2020 from a Swiss WWTP serving between 20000 and 23000 inhabitants. A liquid chromatography mass spectrometry (R > 100000) method, in combination with an atmospheric pressure chemical ionization source (LC-APCI-MS), was used to detect mass spectra of CPs and olefinic side products. A R-based automated spectra evaluation routine (RASER) was applied to search for ∼23000 ions whereof ∼6000 ions could be assigned to CPs, chlorinated mono- (COs), di- (CdiOs) and tri-olefins (CtriOs). Up to 230 CP-, 120 CO-, 50 CdiO- and 20 CtriO-homologues could be identified in sludge. Characteristic fingerprints were deduced describing C- and Cl-homologue distributions, chlorine- (nCl) and carbon- (nC) numbers of CPs and COs. In addition, proportions of saturated and unsaturated material were determined together with proportions of different chain length classes including short- (SC), medium- (MC), long- (LC) and very long-chain (vLC) material. A substantial reduction of SCCPs of 84% was observed from 1993 to 2020. Respective levels of MCCPs, LCCPs and vLCCPs decreased by 61, 69 and 58%. These trends confirm that banned SCCPs and non-regulated CPs are present in WWTP sludge and higher-chlorinated SCCPs were replaced by lower chlorinated MCCPs. Combining high-resolution mass spectrometry with a selective and fast data evaluation method can produce characteristic fingerprints of sewage sludge describing the long-term trends in a WWTP catchment area

The 2015 Annual Meeting of SETAC German Language Branch in Zurich (7-10 September, 2015): ecotoxicology and environmental chemistry-from research to application

This report provides a brief review of the 20th annual meeting of the German Language Branch of the Society of Environmental Toxicology and Chemistry (SETAC GLB) held from September 7th to 10th 2015 at ETH (Swiss Technical University) in Zurich, Switzerland. The event was chaired by Inge Werner, Director of the Swiss Centre for Applied Ecotoxicology (Ecotox Centre) Eawag-EPFL, and organized by a team from Ecotox Centre, Eawag, Federal Office of the Environment, Federal Office of Agriculture, and Mesocosm GmbH (Germany). Over 200 delegates from academia, public agencies and private industry of Germany, Switzerland and Austria attended and discussed the current state of science and its application presented in 75 talks and 83 posters. In addition, three invited keynote speakers provided new insights into scientific knowledge ‘brokering’, and—as it was the International Year of Soil—the important role of healthy soil ecosystems. Awards were presented to young scientists for best oral and poster presentations, and for best 2014 master and doctoral theses. Program and abstracts of the meeting (mostly in German) are provided as Additional file 1

Dioxins and PCBs in Meat – Still a Matter of Concern?

Polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) summarized as dioxins, as well as polychlorinated biphenyls (PCBs) are persistent, bio-accumulative and toxic environmental contaminants. Over 95% of human exposure to these problematic chemicals occurs via the ingestion of fatty rich food like meat and meat products, fatty fish, as well as milk and dairy products. Several major food and feed contamination incidents in Europe during the years 1997 and 2010 revealed the necessity of establishing food and feed monitoring programs for dioxins and PCBs. Various monitoring programs carried out by the Federal Office of Public Health (FOPH) and the Federal Food Safety and Veterinary Office (FSVO), suggest that cattle from extensive farming (suckler cow husbandry) exhibited higher levels of dioxin-like PCBs (dl-PCBs) and exceeded with higher frequency the permitted maximum levels (ML) when compared to conventional raised cattle. The reasons for the higher levels are possibly due to higher levels of PCBs in green fodder (pasture, silage, and hay) when compared to the concentrated feed used in conventional farming. Additionally, an increased uptake of soil, which is known to be a risk matrix for the uptake of dioxins and PCBs in grazing animals, leads to elevated contaminant levels in the suckler cows and hence their calves. Furthermore, PCB point sources present on a farm from older building and construction materials (e.g. PCB-containing wall paints) might result in very high contamination of the animals and the meat produced from them

Determination of PCDD/F, PCBs and PBDE in Swiss sewage sludge

M. Muñoz agradece el apoyo económico de la Universidad de Alicante, al proyecto CTQ 2008-05520 del Ministerio Español de Economía y Competitividad y al Departamento de Química Analítica de EMPA (Dübendorf, Suiza) por permitir el desarrollo de la estancia de investigación