Consumer safety evaluation after monitoring of endocrine disruptor pesticide residues: a case study of Thessaly,Central Greece

Abstract

A large number of pesticides used in agricultural practice has been characterized or suspected to be Endocrine Disruptors, with dietary intake to be the major route of consumer’s exposure. In the present study the safety to consumer after the consumption of pome fruits and fruiting vegetables originated from the area of Thessaly, Central Greece was assessed. Objective samplings of 110 samples were conducted in local retail markets in an effort to quantify potential residues of targeted pesticides, previously characterized as endocrine disruptors. For the determination of residues, a QuEChERs-based multiresidue method coupled with liquid and gas chromatographic systems was applied and fully validated in accordance with the European Unions’s requirements in apples and tomatoes in three fortification levels. Acceptable results were obtained for all the validation parameters studied and the limit of quantification of 0.01?mg/kg and limit of detection of 0.0033?mg/kg were achieved. Based on the determined results, the most frequently determined pesticide was chlorpyrifos with a maximum concentration of 0.32?mg/kg in tomato samples. Cypermethrin and dimethoate were also determined in tomatoes and aubergines. The EFSA PRIMo rev.3.1 model was applied for all positive samples and acute risk for consumers was confirmed only in the case of determination of chlorpyrifos in tomatoes.     

Study of the effects of bisphenol A using human fetal lung fibroblasts

正Bisphenol A(BPA,2,2-bis(4-hydroxyphenyl)propane;CAS#80-05-7)is a highly produced industrial chemical,with an estimated four billion kilograms produced worldwide each year(reviewed in Vandenberg et al.,2010).BPA serves as a monomer in the manufacture of polycarbonate,a hard,clear plastic.Polycarbonate plastics are used in many consumer products,such as reusable water bottles.BPA is also widely used to make epoxy resins,which are used as coating on the inside of some     

Insights into the structural and conformational requirements of polybrominated diphenyl ethers and metabolites as potential estrogens based on molecular docking

PBDEs and their metabolites are of concern due to their increasing concentrations in the environment and their toxic effects. Knowledge about the toxicological mechanisms of PBDEs and metabolites is urgently needed for further screening. The objective of the present study was to explore the structural and conformational requirements of PBDE compounds as human estrogen receptor alpha (hERα) agonists, and further screened out hERα agonists from PBDE compounds. Molecular docking and postdocking analysis were adopted to attain the aim. The obtained results revealed that PBDEs can be primarily screened for their estrogenicity using score values, hydrogen bonds interaction with amino acid residues Glu353 and/or Arg394 might be important for HO-PBDEs’ estrogenicity. For most MeO-PBDEs, hydrophobic interaction might be the key factor affecting their estrogenic activity. The current study suggested that molecular docking and postdocking analysis can serve as an efficient pre-screening technique for identifying potential estrogens.     

Toxics Use Reduction in the Home: Lessons Learned from Household Exposure Studies

Workers and fence-line communities have been the first to benefit from the substantial reductions in toxic chemical use and byproducts in industrial production resulting from the Massachusetts Toxics Use Reduction Act (TURA). As TURA motivates reformulation of products as well as retooling of production processes, benefits could extend more broadly to large-scale reductions in everyday exposures for the general population. Household exposure studies, including those conducted by Silent Spring Institute, show that people are exposed to complex mixtures of indoor toxics from building materials and a myriad of consumer products. Pollutants in homes are likely to have multiple health effects because many are classified as endocrine disrupting compounds (EDCs), with the ability to interfere with the body’s hormone system. Product-related EDCs measured in homes include phthalates, halogenated flame retardants, and alkylphenols. Silent Spring Institute’s chemical analysis of personal care and cleaning products confirms many are potential sources of EDCs, highlighting the need for a more comprehensive toxics use reduction (TUR) approach to reduce those exposures. Toxics use reduction targeted at EDCs in consumer products has the potential to substantially reduce occupational and residential exposures. The lessons that have emerged from household exposure research can inform improved chemicals management policies at the state and national levels, leading to safer products and widespread health and environmental benefits.     

Occurrence and temporal variations of the xenoestrogens bisphenol A, 4-<Emphasis Type="Italic">tert</Emphasis>-octylphenol,and tech. 4-nonylphenol in two German wastewater treatment plants

GOAL, SCOPE, AND BACKGROUND: The xenoestrogens bisphenol A, 4-tert-octylphenol, and the technical isomer mixture of 4-nonylphenol (tech. 4-nonylphenol) belong to the group of chemicals which are called endocrine disrupters due to their property of causing hormonal dysfunctions in the endocrine system of organisms at very low concentrations. Bisphenol A, 4-tert-octylphenol, and the tech. 4-nonylphenol (mixture of isomers) were determined in water samples collected from the influent and effluent of two German wastewater treatment plants (WWTP) during a long-time sampling period from February 2003 till August 2005 to assess their occurrence and temporal variations in WWTPs. METHODS: The compounds were extracted and concentrated from water by solid-phase extraction (SPE) using Bond Elut PPL cartridges and quantified by use of gas chromatography-mass spectrometry (GC-MS). RESULTS: The influent concentrations were as follows: Bisphenol A < limit of detection of the method (< ldm)--12,205 ng L(-1), tech. 4-nonylphenol < ldm--10,186 ng L(-1), and 4-tert-octylphenol 39-1,495 ng L(-1). The measured effluent concentrations were lower with values in the range of < ldm--7,625 ng L(-1) for bisphenol A, < ldm--14,444 ng L(-1) for tech. 4-nonylphenol, and < ldm--392 ng L(-1) for 4-tert-octylphenol. All target compounds were largely eliminated during the wastewater treatment process. The elimination efficiency varied between 73% and 93%. DISCUSSION: All analytes show highly fluctuating influent concentrations with very high peak concentrations at particular sampling times. The variation of effluent concentrations is by far lower than the variation of influent concentrations. For tech. 4-nonylphenol, a significant temporal concentration variation has been detected with very high concentrations up to the microgram-per-liter level in the time from February 2003 till July 2003 and clearly decreasing concentrations in the time from June 2004 till August 2005. This corresponds well with the implementation of Directive 2003/53/EC (nonylphenol and nonylphenol ethoxylates in the European Union "may not be placed on the marked or used as a substance or constituent of preparations in concentrations equal or higher than 0.1% by mass") from January 2005 on. Bisphenol A is present in the effluent samples in a wide range of concentrations from below the detection limit to high concentrations up to the microgram-per-liter level. For 4-tert-octylphenol, no particular trend of concentration development has been observed. CONCLUSIONS: Combined SPE and GC-MS proved to be an efficient method to identify and quantify polar organic compounds in environmental samples. With respect to the concentrations measured in the present study, bisphenol A sometimes is the prominent compound in influent samples. Neither bisphenol A nor 4-tert-octylphenol or tech. 4-nonylphenol show seasonal variations. However, there was a significant general trend of decreasing concentrations of tech. 4-nonylphenol in influent and effluent samples from both WWTPs which probably reflects the implementing Directive 2003/53/EC. RECOMMENDATIONS AND PERSPECTIVES: Further research is needed to investigate whether the observed decrease of tech. 4-nonylphenol concentrations in German WWTPs since June 2004 will continue further on. The reason for the high effluent concentrations of bisphenol A in only a few samples has to be clarified in further research. The results from this study provide insight into the concentration development of the xenoestrogens bisphenol A, tech. 4-nonylphenol, and 4-tert-octylphenol in WWTPs in the time span between 2003 and 2005.     

Mass fluxes and spatial trends of xenobiotics in the waters of the city of Halle, Germany

The behaviour and the effects of xenobiotics including pharmaceuticals and fragrances in the environment are widely unknown. In order to improve our knowledge, field investigations and modelling approaches for the entire area of the city of Halle/Saale, Germany, were performed. The distribution of the concentration values and mass fluxes are exemplified using indicators such as Bisphenol A, t-Nonylphenol, Carbamacepine, Galaxolide, Tonalide, Gadolinium and isotopes. Concentrations at a magnitude of ng/L to microg/L were found ubiquitously in the ground and surface waters. Using the concentration values, the impact of the city concerning the indicators was not always evident. Only the assessment of the mass fluxes shows significant urban impacts along the city passage. The calculation of the mass fluxes shows increasing values for all investigated xenobiotics during the city passage; only Bisphenol A stagnates. A balance model of water and indicator mass fluxes was built up for the entire city area.     

典型新兴环境污染物的研究进展

概述了内分泌干扰物(EDCs)、药物及个人护理品(PPCPs)等典型新兴环境污染物的主要类型、环境浓度、分析方法、来源与归趋以及国内外研究进展。内分泌干扰物、药物及个人护理品在世界各地的污水处理厂出水中检出,表明了污水处理技术的不完善性,亟需研究并应用更全面的污水处理技术,以从源头上阻断新兴环境污染物对环境的污染。     

Overcoming the toxicity effects of municipal wastewater sludge and biosolid extracts in the Yeast Estrogen Screen (YES) assay

For nearly two decades, the Yeast Estrogen Screen (YES) has been used as a valuable tool for determining the total estrogenic potency of various environmental samples, including influent and effluent streams at municipal wastewater plants. However, applying the YES assay to wastewater sludges and stabilized biosolids has been problematic. This is due to co-extracted compounds from the solids either proving toxic to the yeast or masking the presence of estrogenic substances. The present research describes the development and validation of sample preparation steps that mitigate the toxicity effects of municipal wastewater sludge and biosolid samples in the YES assay, while allowing for reliable dose-dependent expression of estrogenic activity. A copper work-up for sulfur removal and chromatographic cleanup with silica and alumina were required in addition to solid-phase extraction to adequately remove interfering compounds. Sample stabilization methods such as autoclaving, lyophilization and formaldehyde treatment were found to be detrimental to the assay. Hence, heat-drying is recommended to prevent cytotoxicity and the degradation of estrogenic substances.     

The OECD Validation Program of the H295R Steroidogenesis Assay for the Identification of In Vitro Inhibitors and Inducers of Testosterone and Estradiol Production. Phase 2: Inter-Laboratory Pre-Validation Studies (8 pp)

Background, Goals and Scope In response to concerns that have been raised about chemical substances that may alter the function of endocrine systems and result in adverse effects on human health, an OECD initiative was undertaken to develop and validate in vitro and in vivo assays to identify chemicals that may interfere with endocrine systems of vertebrates. Here we report on studies that were conducted to develop and standardize a cell-based screening assay using the H295R cell line to prioritize chemicals that may act on steroidogenic processes in humans and wildlife. These studies are currently ongoing as part of the ‘Special Activity on the Testing and Assessment of Endocrine Disruptors’ within the OECD Test Guidelines Program to review, develop, standardize, and validate a number of in vitro and in vivo toxicological assays for testing and assessment of chemicals concerning their potential to interact with the endocrine system of vertebrates. Study Design Six laboratories from five countries participated in the pre-validation studies. Each laboratory tested the effects of three model chemicals on the production of testosterone (T) and estradiol (E2) using the H295R Steroidogenesis Assay. Chemicals tested were well described inducers or inhibitors of steroidogenic pathways (forskolin, prochloraz and fadrozole). All experiments were conducted in 24 well plates following standard protocols. Six different doses per compound were analyzed in triplicate per plate. A quality control (QC) plate was run in conjunction with the chemical exposure plate to account for inter-assay variation. Each chemical exposure was conducted two or three times. Results All laboratories successfully detected increases and/or decreases in hormone production by H295R cells after exposure to the different model compounds and there was good agreement in the pattern of response for all groups. Forskolin increased both T and E2 while fadrozole and prochloraz decreased production of both hormones. All chemicals affected hormone production in a dose-dependent manner with the exception of fadrozole which caused maximum inhibition of E2 at the two least concentrations tested. Some inter-laboratory differences were noted in the alteration of hormone production measured in chemically exposed cells. However, with the exception of the production of T measured at one laboratory in cells exposed to forskolin, the EC₅₀s calculated were comparable (coefficients of variation 34–49%) for all hormones. Discussion and Perspectives The results indicated that the H295R Steroidogenesis Assay protocol was robust, transferable and reproducible among all laboratories. However, in several instances that were primarily related to one laboratory there were unexplained minor uncertainties related to the inter-laboratory hormone production variation. Based on the findings from this Phase 2 prevalidation study, the H295R Steroidogenesis Assay protocol is currently being refined. The next phase of the OECD validation program will test the refined protocol among the same group of laboratories using an extended set of chemicals (∼30) that will include positive and negative chemical controls as well as a broad spectrum of different potential inducers and inhibitors of steroidogenic pathways. Submission Editor: Dr. Carsten Brühl (bruehl@uni-landau.de)