Research progress on the role of environmentally induced DNA methylation in congenital cleft lip and/or palate / 口腔疾病防治

@#Congenital cleft lip and/or palate (CL/P) is a common malformation of maxillofacial development. At present, it is believed that the etiology of congenital cleft lip and palate mainly results from genetic factors and environmental factors. Epigenetic changes induced by environmental factors may be the key factor in the occurrence of fetal congenital malformations. As one of the important epigenetic modifications, DNA methylation has been widely and deeply studied in many fields, but as a link between the individual and the environment, its application in CL/P is limited. Existing studies have shown that DNA methylation is closely related to the occurrence of cleft lip and palate. Stimulation of folate deficiency, smoking, pollutant exposure and other environmental factors can induce changes in the state of DNA methylation, thus affecting gene expression in the development of lip and palate and leading to the occurrence of deformities.

Quantitative risk assessment of occupational exposure to PCDD/Fs in the waste incineration industry / 中华劳动卫生职业病杂志

Objective: To analyze the level of PCDD/Fs exposure of occupational workers in the waste incineration industry and explore the risk of occupational exposure. Methods: In September 2021, literature on environmental PCDD/Fs exposure in waste incineration plants published from the establishment of the database to February 10, 2021 was retrieved from CNKI database. A total of 1365 literatures were retrieved, and 7 met the criteria for inclusion. The US Environmental Protection Agency (EPA) inhalation risk model was used to assess and analyze carcinogenic and non-carcinogenic risks of PCDD/Fs exposure among occupational workers in the waste incineration industry. Results: A total of 86 sampling sites were included in incineration plants in 7 regions. The study of Wuhan area showed that the concentration of working environment near the waste incinerator in the same factory was the highest, followed by the rest and office area in the factory. The concentration of PCDD/Fs in waste incinerators was the highest in Southwest China (4880.00-24880.00 pg TEQ/m(3)), and the lowest in Shenzhen (0.02-0.44 pg TEQ/m(3)). According to the cancer risk assessment, with the increase of exposure years, the risk of cancer increased. The highest risk of cancer was found in the waste incineration plants in Southwest China. When the exposure period was 1 year, the risk was moderate (22.40×10(-6)-114.20×10(-6)). When the exposure time was more than 5 years, the risk of cancer was high. In Jinan, workers working near the incinerator had a moderate risk of cancer after five years of exposure. In Zhejiang, workers were at medium risk of cancer after exposure for more than 20 years. Workers in Wuhan, Shanghai, Zhejiang Province, Shenzhen and the Pearl River Delta were still at low risk of cancer after 40 years of occupational exposure. HQ>1 of workers working near the waste incinerators in Jinan, Zhejiang Province and Southwest China, and the qualitative evaluation results showed that the non-carcinogenic risk was unacceptable. Conclusion: There are great differences in PCDD/Fs of occupational exposure in waste incineration industry, and the occupational exposure exceeding the occupational exposure limit has higher carcinogenic and non carcinogenic risks.

Pollution status and health effect of dioxins in the atmosphere / 上海预防医学

Dioxin, a persistent organic pollutant, is also a typical environmental endocrine disruptor.With its strong toxicity, it can persist in the environment and be enriched through the food chain.Therefore, it has attracted wide attention in recent years.In this paper, the pollution status of dioxins in the atmosphere is summarized, the risk of respiratory exposure to dioxins is introduced, the possible health effects of human exposure to dioxins are summarized, and suggestions for future control are put forward.In cities and functional areas with high dioxin concentration, long-term inhalation of pollutants has potential risks for people′s health and life span.It is suggested to carry out orderly classification of waste, track and monitor the health status of residents around the waste incinerator, and to establish relevant emission standards and limits, so as to gradually standardize and make the dioxin emission harmless.

Dioxins levels in human blood after implementation of measures against dioxin exposure in Japan

BACKGROUND@#Over the past few decades, the Japanese Ministry of the Environment has been biomonitoring dioxins in the general Japanese population and, in response to public concerns, has taken measures to reduce dioxin exposure. The objectives of this study were to assess the current dioxin dietary intake and corresponding body burden in the Japanese and compare Japanese dioxin data from 2011 to 2016 and 2002-2010 surveys. We also examined the relationship between blood dioxins and health parameters/clinical biomarkers.@*METHODS@#From 2011 to 2016, cross-sectional dioxin surveys were conducted on 490 Japanese (242 males and 248 females, aged 49.9 ± 7.6 years) from 15 Japanese prefectures. Blood (n = 490) and food samples (n = 90) were measured for 29 dioxin congeners including polychlorinated dibenzo-para-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and coplanar polychlorinated biphenyls (Co-PCBs) using gas chromatography coupled with high-resolution mass spectrometry. Using the 2006 World Health Organization toxic equivalence factors, the toxic equivalents (TEQs) were calculated. Clinical biomarkers and anthropometric parameters were also measured and information on lifestyle behaviours collected. Data imputations were applied to account for blood dioxins below the detection limit.@*RESULTS@#The median (95% confidence interval or CI) blood levels and dioxin dietary intake was respectively 9.4 (8.8-9.9) pg TEQ/g lipid and 0.3 (0.2-0.4) pg TEQ/kg body weight/day. The median blood dioxin level in the 2011-2016 survey was found to have decreased by 41.3% compared to the 2002-2010 surveys. Participants who were older were found to be more likely to have higher dioxin levels. Blood dioxins were also significantly associated with body mass index, triglycerides, docosahexaenoic acid, eicosapentaenoic acid, and dihomo-gamma-linoleic acid levels in blood. Furthermore, associations between blood dioxin and dietary dioxin intake were evident in the unadjusted models. However, after adjusting for confounders, blood dioxins were not found to be associated with dietary dioxin intake.@*CONCLUSIONS@#Blood dioxin levels declined over the past decade. This study showed that the measures and actions undertaken in Japan have possibly contributed to these reductions in the body burden of dioxins in the Japanese population.

Research progress on exposure levels and toxic pathways of typical persistent organic pollutants in foods / 中华预防医学杂志

Dioxins, polybrominated diphenyl ethers, and benzo(a)pyrene are common organic pollutants in food. They have been of concern to academics and government administrations due to high residue and persistence, easy accumulation and strong harmful effects. The National Research Council of the United States of America published Toxicity Testing in the 21st Century: A Vision and Strategy in 2007, which proposed a new concept of toxicity testing that toxicity testing should take full consideration of population exposure data and base on in vitro tests, human cell lines, toxicity pathways and high-throughput screening. Meanwhile, systems biology, bioinformatics and rapid assay technologies will be used to better understand toxicity pathways—the cellular response pathways that can lead to adverse health effects when sufficient perturbing induced by chemicals exposure. The new toxicity testing strategy has changed the traditional testing pattern and has brought a wide impact on the international relevant fields. The European Union, the World Health Organization, and the United States Environmental Protection Agency, the Food and Drug Administration, and the National Center for Toxicological Research have organized relevant discussions and exploratory studies to address the new toxicity testing concept and how to evaluate and utilize the results of traditional toxicity test researches. Compared to the discussion, 'whether to do it’, ten years ago, the question, 'how to do it’, has become the concern of the current discussion. Therefore, how to respond to the concept of toxicity testing and how to effectively utilize and excavate traditional toxicity test data have been the focus of multi-disciplines and interdisciplinary academia such as toxicology, food hygiene and environmental science. Therefore, this article provides an overview of the exposure levels of dioxin, polybrominated diphenyl ethers and benzo[a]pyrene, which are typical persistent organic pollutants in food in China and the current research status of toxic pathways based on whole animal experiments. The exposure level, toxic effect and toxicity mechanism of three contaminants are analyzed and summarized in order to provide basis for future results based on the 21st century toxicity test compared with traditional tests and data mining analysis of these two kinds of data. Meanwhile, it also lays the foundation for the establishment of a toxicity testing framework based on exposure characteristics, toxic pathways, and biomarkers.

Risk assessment of dioxin in the surrounding area of a waste incineration plant in Beijing / 中华预防医学杂志

Objective@#Assess the health risks faced by local residents, based on the results of dioxin detection in the surrounding area of a waste incineration plant in Beijing.@*Methods@#Select three representative points plant near the waste incineration plant--the people's government, Central Primary School and a community, collect 4 air and soil samples and detect their dioxin concentrations from March to December 2016, respectively, simulate people's intake through breathing, skin contact and soil intake, assess residents' lifetime cancer risk according to epidemiological studies.@*Results@#The daily average concentration in air at three test points were 0.15, 0.17, 0.19 pg/m3, and 12.5, 20.2, 6.1 ng/kg in soil. At three representative sites, residents' lifetime cancer risk through breathing from 9.55×10-6, 1.08×10-5, 1.21×10-5 in the people's government, Central Primary School and a community, while through skin contact were 3.40×10-7, 5.50×10-7, 1.65×10-7, respectively. The lifetime cancer risk through soil intake range from 2.08×10-6 to 6.91×10-6. The lifetime cancer risk of eating vegetables ranges from 5.50×10-6 to 6.98×10-6. The lifetime cancer risk of eating chicken or eggs ranges from 2.72 ×10-9 to 6.30×10-9. Residents' lifetime cancer risk through soil intake, eating vegetables and eating chicken or eggs ranges from 2.08×10-6 to 6.30×10-9.@*Conclusion@#Under all exposures, the life time risk of cancer for residents around the waste incineration is under the upper end of the range of acceptability(10-4).

Aryl hydrocarbon receptor overexpression in miniaturized follicles in female pattern hair loss

Abstract The etiopathogenesis of female pattern hair loss is still poorly understood. In addition to genetic and hormonal elements, environmental factors could be involved. The aryl hydrocarbon receptor is expressed in keratinocytes and can be activated by environmental pollutants leading to alterations in the cell cycle, inflammation, and apoptosis. Here we demonstrate the overexpression of nuclear aryl hydrocarbon receptors in miniaturized hair follicles in female pattern hair loss.

Determination of Dioxin-like Compounds in Soil byAccelerated Solvent Extraction-Silica Gel Column Cleanup-BasicAlumina Column Separation Coupled with Gas Chromatography-Triple Quadrupole Mass Spectrometry / 分析化学

A method for determination of PCDD/Fs, PCBs and PCNs in soil sample was developed by using accelerated solvent extraction (ASE)-silica gel column cleanup-basic alumina column separation coupled with GC-MS/MS.The sample was extracted by ASE with Hexane-methylene chloride (Hex-DCM, 50∶50, V/V) at 120℃.The basic alumina column was used to separate PCDD/Fs, PCBs and PCNs.The extracts were eluted with Hex-DCM (95∶5, V/V) to obtain PCBs and PCNs, followed by Hex-DCM (50∶50, V/V) to obtain PCDD/Fs.The limits of detection (LOD) were in the range of 0.04-0.25 μg/L, 0.10-0.20 μg/L and 0.01-0.05 μg/L for PCDD/Fs, PCBs, PCNs, respectively.The relative standard deviations (RSDs) of average relative response factors (RRF) were below 13%.The recoveries of 13C-labeled internal standards of the three classes of analytes were 50%-95%, 51%-103% and 49%-74%, respectively.Concentrations of ∑PCDD/Fs, ∑PCBs and ∑PCNs in soil samples were 16.1-1148 pg/g, 6.6-152.6 pg/g and 10.9-99.5 pg/g, respectively.The results were consistent with that of high resolution mass spectrometer.

Determination of Dioxin in Waste Printed Circuit Boards by Accelerated Solvent Extraction and Soxhelt Extraction / 分析化学

Waste printed circuit boards(W-PCBs) were multiple smashed and separated, then passed through a 60-mesh screen, treated with hydrochloric acid (2 mol/L), ultrapure water and dehydrated with acetone successively.The filter residue and filter paper were filled into the extraction pool, or inserted into Soxhlet Extraction tube parceled with new filter paper.After addition of 5 μL of internal standard substance, the filter residue above was respectively extracted by Soxhlet Extraction (SE) method or Accelerated Solvent Extraction (ASE) method, cleaned with multi-layer silica gel column and activated-charcoal column to obtained the dioxins samples.The samples were analyzed by isotope dilution high resolution gas chromatography-high resolution mass spectrometry (HRGC-HRMS).The effects of SE and ASE method and number of chlorines atoms on recovery of 15 kinds of 13C-2,3,7,8 PCDD/Fs were investigated, and the accuracy and precision of the two extraction methods were compared.The results show that, the recovery of 15 kinds of 13C-2,3,7,8 PCDD/Fs using ASE method is 54.3%-113.0%, and that of SE is 28.3%-77.7%, and the Toxic Equivalent Quangtity (TEQ) in W-PCBs is 0.075 ng/kg (TEQ) and 0.266 ng/kg (TEQ) using ASE and SE method respectively.Under the premise that accuracy and precision meet with the international standard, ASE is simple, rapid, solvent-free and accurate.

Benefit-risk Assessment of Fish and Fish Products in the Norwegian Diet – An Update.

Request from the Norwegian Food Safety Authority (NFSA) In September 2013, the Norwegian Food Safety Authority requested VKM to update relevant parts of the benefit-risk assessment of fish in the Norwegian diet published by VKM in 2006. The background for the request was new knowledge and data on the content of some nutrients and contaminants both for wild and farmed fish since 2006. The proportion of vegetable ingredients used in farmed fish feed has in recent years increased, and new national dietary surveys for adults and children have been conducted. The Norwegian Food Safety Authority referred to VKM’s report from 2006, which pointed out that the positive impact of fish consumption on public health was especially due to the content of polyunsaturated fatty acids and vitamin D in fish. Further, VKM concluded that the contaminants that could pose a potential risk to public health through fish consumption mainly were methylmercury, dioxins and dioxin-like PCBs (dl-PCBs). The request included a reassessment of fish consumption in Norway with focus on specific nutrients; n-3 fatty acids (eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), docosahexaenoic acid (DHA), vitamin D, and the minerals iodine and selenium, and on specific contaminants; mercury, dioxins and dl-PCBs. VKM was asked to address the main changes in the use of raw materials in farmed fish feed and how these affect the levels of nutrients, mercury, dioxins and dl-PCBs and in fish feed. Further, VKM was asked to address to what extent levels of nutrients and contaminants in fish have changed since 2006, to describe these changes and estimate the human intake of the substances in question on the basis of recent dietary data. VKM was also requested to consider the benefits of eating fish with regard to the intake of nutrients and the risks associated with the intake of mercury, dioxins and dl-PCBs and comment on whether this change the conclusions from the report in 2006. Additionally, on the basis of updated knowledge, VKM was asked to comment whether other substances, like pesticide and residues of veterinary medicinal products, could affect the conclusions with regard to the impact on public health. The Norwegian Food Safety Authority and the Directorate of Health will use the updated assessment as a basis for public recommendations concerning the consumption of fish and fish products. How VKM has Addressed the Request The VKM appointed a working group consisting of VKM members and external experts to answer the request. Several of the scientific panels of VKM reviewed the report during its preparation. The Scientific Steering Committee of VKM has given their final assessment and approval of the current report. In the current report, VKM has mainly used data from national surveillance and monitoring programs for nutrient and contaminant concentrations in fish feed, farmed fish and wild caught fish, but occurrence data have also been derived from peer reviewed articles. VKM has estimated fish consumption in three population groups (2-year-olds, adults and pregnant women). The estimated fish consumption was compared to national dietary guidelines. To assess health effects of fish consumption, the current estimated fish intakes were also compared with assessments done by recognised international bodies and results from epidemiological studies addressing possible associations between fish consumption and specific health outcomes. Literature searches were done to identify relevant epidemiological studies. VKM has not systematically assessed reviews or meta-analyses nor individual studies for weight of evidence, but merely summarised the studies retrieved from the literature search. It was considered being beyond the scope of this assessment to review individual studies included in reviews or meta-analyses. Furthermore, based on current fish consumption in the various population groups, intake of nutrients and exposure to contaminants from fish were estimated. For benefit characterisation of the specific nutrients the estimated nutrient intake was compared with national recommendations of nutrients intake and for EPA and DHA a comparison was also done with European recommendations. For risk characterization of contaminant exposure from fish, VKM used health based guidance values set by international risk assessment bodies (WHO, EFSA). VKM noted that the request from NFSA was restricted to fish, whereas the VKM report in 2006 included both fish and other seafood. VKM focused on specific nutrients and contaminants as requested by the NFSA. In addition, VKM also commented on other substances that could affect the risk assessment, such as residues of veterinary medicinal products including residues of antibiotics, new contaminants from fish feed like the pesticide endosulfan, polycyclic aromatic hydrocarbons (PAHs), mycotoxins, the synthetic antioxidants ethoxyquin, butylhydroxyanisole (BHA) and butylhydroxytoluene (BHT), as well as environmental contaminants like brominated flame retardants and perfluorated organic compounds Background In the Norwegian diet fish is important source of well-balanced proteins, and important nutrients such as EPA and DHA, vitamin D, iodine and selenium. On the other hand, fish is also a source of exposure to chemical contaminants like dioxins, PCBs and mercury. Over the last 10 years there has been a great change in raw materials used in fish feeds, and in 2013 terrestrial plant proteins and vegetable oils accounted for 70% of the feed. The changes in concentrations of nutrients and contaminants in fish feed for farmed Atlantic salmon and trout are reflected in changed concentrations and compositions of the same nutrients and contaminants in the farmed fish fillet. The current national dietary guideline is to eat fish as dinner meals 2-3 times per week for all age groups, representing 300-450 g fish per week for adults, including at least 200 g fatty fish, such as salmon, trout, mackerel and herring. Fish is also recommended as bread spread. Further, a daily supplement of vitamin D to infants from 4 weeks of age is recommended, and if this supplement is taken as cod liver oil it will in addition ensure an adequate supply of EPA and DHA. The present benefit-risk assessment is comprised of three elements, i.e. benefit assessment, risk assessment and benefit-risk comparison. This methodology is in accordance with the guidance given by EFSA in 2010. Fish Consumption in Norway and Comparison with National Dietary Guidelines VKM has used information about fish consumption from more recent national dietary surveys among 2-year-olds (Småbarnskost 2007) and adults at 18-70 years of age (Norkost 3, 2010/2011), as well as information for pregnant women who answered the Norwegian Mother and Child Cohort Study (MoBa2, 2002-2008) food frequency questionnaire. The national food consumption survey Ungkost 2000, which covers the age groups 4-, 9-, and 13-year-old children, was considered too old to be used and it is therefore not known if their fish consumption patterns have changed, neither in amount consumed nor type of fish consumed. Even though there are methodological differences between the dietary surveys used in 2006 and 2014, the amount of fish consumed appears to be unchanged for all population groups. Furthermore, in 2014, lean fish and fatty fish contribute with about 60 and 40 percent, respectively, of the total fish consumption, which is similar to 2006. Given a portion size of 150 g fish, the average adult eats fish equivalent to 2-3 dinner servings per week and the average pregnant woman eats fish equivalent to 1-2 dinner servings per week, while the average two-year-old eats fish equivalent to 1-2 dinner servings per week given a portion size of 75 g. The table below describes fish intake in the selected populations. Fish consumption (expressed as raw fish), mean grams (g) per week in 2-year-olds (Småbarnskost 2007, n=1674), adults (Norkost 3, n=1787) and pregnant women (MoBa, n=86277) Population groups Mean fish consumption g/week Fish roe Fish, total Lean fish (≤ 5% fat) Fatty fish (> 5% fat) and liver 2-year-olds 112 70 35 7 Adults 364 210 147 7 Pregnant women 217 126 77 14 VKM concludes that of the different population groups, only adults (18-70 years of age) with an average or higher fish consumption reach the national food based dietary guidelines for total fish consumption. Mean total fish consumption and fatty fish consumption in children (2-year-olds) and pregnant women, as well as the mean fatty fish consumption in adults are lower than recommended. In pregnant women and 2-year-olds, fish consumption is too low to meet the food based dietary guidelines Health Effects of Fish Consumption VKM is of the opinion that according to epidemiological studies, the net effects of the present average fish consumption in Norway for adults including pregnant women is beneficial for specific cardiovascular diseases (particularly cardiac mortality, but also with regard to ischaemic stroke, non-fatal coronary heart disease events, congestive heart failure and atrial fibrillation), as well as for optimal neurodevelopment of foetus and infants. Furthermore, VKM is of the opinion that those with fish consumption less than one dinner serving per week may miss these beneficial effects. The health benefit of fish consumption is reported from 1-2 dinner servings per week and up to 3-4 dinner servings per week. For higher fish intake per week, the limited number of consumers in epidemiological studies does not allow for drawing firm conclusions about the actual balance of risk and benefit. More knowledge is needed to reveal the beneficial mechanisms of fish consumption. Benefit Characterisation of Nutrients in Fish VKM is of the opinion that there has been minor or no changes of the composition and concentrations of nutrients in wild caught fish since 2006. Due to replacement of fish oil and fish protein with plant prote

Determination of Polychlorinated Dibenzo-p-dioxins/Dibenzofurans, Dioxin Like Polychlorinated Biphenyls, Brominated Flame Retardants and Polybrominated Dibenzo-p-dioxins/Dibenzofurans in Flue Gas from Stationary Source / 分析化学

A method for simultaneous determination of PCDDs, dl-PCBs, BFRs and PBDD/Fs in flue gas from stationary source was developed. The sample was extracted by Soxhlet apparatus with toluene, and followed by purification through sulfuric acid partition and multi-layer silica gel column separation. The target compounds were then all separated by passing through the active carbon-dispersed silica gel column and reversal eluting. Gas chromatography coupled with a thermostable capillary column ( short length, thin stationary phase film) was operated at pulse injection mode. High resolution mass spectrometry set at low-electron-energy ionization was used for quantification. The high- and low-brominated compounds were determined simultaneously. The detection limits of this method were 0. 081-1. 2 pg for PCDD/Fs, 0. 10-0. 32 pg for dl-PCBs, 0. 14-12 pg for PBDEs, 0. 26-16 pg for new BFRs, 0. 44-3. 6 pg for tetra- to hepta-BDD/Fs and 8. 2-12 pg for OBDD/F. Recoveries ( RSDs) in spiked flue gas samples were 88%-115%(2. 9%-6. 1%) for PCDD/Fs, 84%-118% (3. 2%-10%) for dl-PCBs, 71%-135% (2. 1%-18%) for PBDEs, 71%-114% (2. 9%-7. 4%) for new BFRs, 83%-127% (5. 2%-10%) for tetra-to hepta-BDD/Fs and 52%-149% ( 23%-24%) for OBDD/F. All quality control data fell within the acceptable range specified in analysis standards for flue gas.

Suburban Breastfed Infants In Klang Valley Are At Higher Risk Of Dioxins Toxicity

Dioxins are a most toxic compound ever studied by human until today. Their significant health effects involved all ranges of age, including infants due to exposure to contaminated breast milk. The objective of the study was to appraise the status of dioxin contamination in breast milk among postnatal mothers live in urban and suburban areas in Klang Valley. It was conducted as a cross sectional study involving 101 postnatal mothers who came for their infant second hepatitis B vaccination. The samples were analysed using High Resolution Gas Chromatography (HRGC) following the USEPA Method 8290. About 70.3% of the samples were found detected with dioxin congeners. More suburban mothers have positive breast milk dioxins compared to urban mothers, 100.0% and 67.0% respectively. Significant associated factors include high fat daily intake (p=0.013), high milk daily intake (p= 0.044), high meat daily intake (p=0.001), body mass index more than 30 kg/m2 (p=0.005), and body fat % of more than 26% (p=0.046). In conclusion, amount daily intake of fat diet, meat, milk, body mass index and body fat are significant associated factors for the present of dioxins in breast milk among postnatal mothers in Klang Valley. More suburban mothers contain dioxins in their breast milk, which poses higher risk of health problems among their infants. A comprehensive study need to be conducted and regular followup need to be established in monitoring the future severity of maternal breast milk contamination to ensure the health of the next generations.

Regulation of CYP1A1 and Inflammatory Cytokine by NCOA7 Isoform 4 in Response to Dioxin Induced Airway Inflammation / 결핵및호흡기질환

BACKGROUND: Aryl hydrocarbon receptor (AhR), a ligand-dependent transcription factor, binds to a wide variety of synthetic and naturally occurring compounds. AhR is involved in the regulation of inflammatory response during acute and chronic respiratory diseases. We investigated whether nuclear receptor coactivator 7 (NCOA7) could regulate transcriptional levels of AhR target genes and inflammatory cytokines in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-treated human bronchial epithelial cells. This study was based on our previous study that NCOA7 was differentially expressed between normal and chronic obstructive pulmonary disease lung tissues. METHODS: BEAS-2B and A549 cells grown under serum-free conditions were treated with or without TCDD (0.15 nM and 6.5 nM) for 24 hours after transfection of pCMV-NCOA7 isoform 4. Expression levels of cytochrome P4501A1 (CYP1A1), IL-6, and IL-8 were measured by quantitative real-time polymerase chain reaction. RESULTS: The transcriptional activities of CYP1A1 and inflammatory cytokines were strongly induced by TCDD treatment in both BEAS-2B and A549 cell lines. The NCOA7 isoform 4 oppositely regulated the transcriptional activities of CYP1A1 and inflammatory cytokines between BEAS-2B and A549 cell lines. CONCLUSION: Our results suggest that NCOA7 could act as a regulator in the TCDD-AhR signaling pathway with dual roles in normal and abnormal physiological conditions.

Dioxins and polychlorinated biphenyls concentrations in Larus dominicanus. Case study: Marambaia island, Sepetiba bay, Rio de Janeiro State, Brazil / Concentrações de dioxinas e bifenilas policloradas em Larus dominicanus. Estudo de caso: ilha da Marambaia, baía de Sepetiba, Estado do Rio de Janeiro, Brasil

Seabirds play a significant role as bioindicators: they are conspicuous, relatively easy to observe, well-established studied group of organisms, and in the focus of public interest due to pollution in aquatic ecosystem. Systematically, a significant number of man-made chemicals have been introduced in the marine environment and represent the major problem arising in the development worldwide. Many of these chemical contaminants are persistent, known to bioaccumulate and biomagnify through the aquatic food web, affecting species associated with aquatic systems. Dioxins [polychlorinated dibenzo-p-dioxins (PCDD), dibenzofurans (PCDF)] and polychlorinated biphenyls (PCB) concentrations were measured in Kelp gull Larus dominicanus collected from 2006 to 2011 on Marambaia Island, Sepetiba Bay, Rio de Janeiro State, Brazil. Detectable liver concentrations of PCDD Fs-1 and PCBs were found in all samples analyzed. These represent some of the first measurements of PCDD Fs-1 and PCBs in seabirds from this area. Although levels of these contaminants in the tested species currently appear to fall below critical values, a continuous and systematic monitoring on these compounds becomes essential and desirable to not express toxic values in the future.

Aves marinhas desempenham uma função significativa como bioindicadores: elas são conspícuas, relativamente fáceis de observar, grupos de organismos de estudo bem estabelecidos e no foco de interesse público devido à poluição no ecossistema aquático. Sistematicamente, um número significativo de produtos químicos sintéticos vêm sendo introduzidos no ambiente marinho, representando um dos principais problemas que se coloca no desenvolvimento em todo o mundo. Muitos desses contaminantes químicos são persistentes, conhecidos por bioacumular e biomagnificar através de suas movimentações na cadeia alimentar, afetando espécies associadas aos sistemas aquáticos. Concentrações de dioxinas [dibenzo-p-dioxinas policloradas (PCDD), dibenzofuranos (PCDF)] e bifenilas policloradas (PCB) foram medidas em gaivotões Larus dominicanus coletadas de 2006 a 2011 na Ilha da Marambaia, Baía de Sepetiba, Rio de Janeiro, Brasil. Estes dados representam algumas das primeiras medições de PCDD Fs-1 e PCBs em aves marinhas nesta área estudada. Embora os níveis destes contaminantes na espécie testada apresentarem níveis abaixo dos valores críticos, o monitoramento contínuo, sistemático, torna-se imprescindível e desejável para que estes compostos não expressem no futuro valores tóxicos.

Serum 2,3,7,8-Tetrachlorodibenzo-p-dioxin Levels and Their Association With Age, Body Mass Index, Smoking, Military Record-based Variables, and Estimated Exposure to Agent Orange in Korean Vietnam Veterans / 예방의학회지

OBJECTIVES: The aim of this study was to examine the levels of serum 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and evaluate their association with age, body mass index, smoking, military record-based variables, and estimated exposure to Agent Orange in Korean Vietnam veterans. METHODS: Serum levels of TCDD were analyzed in 102 Vietnam veterans. Information on age, body mass index, and smoking status were obtained from a self-reported questionnaire. The perceived exposure was assessed by a 6-item questionnaire. Two proximity-based exposures were constructed by division/brigade level and battalion/company level unit information using the Stellman exposure opportunity index model. RESULTS: The mean and median of serum TCDD levels was 1.2 parts per trillion (ppt) and 0.9 ppt, respectively. Only 2 Vietnam veterans had elevated levels of TCDD (>10 ppt). The levels of TCDD did not tend to increase with the likelihood of exposure to Agent Orange, as estimated from either proximity-based exposure or perceived self-reported exposure. The serum TCDD levels were not significantly different according to military unit, year of first deployment, duration of deployment, military rank, age, body mass index, and smoking status. CONCLUSIONS: The average serum TCDD levels in the Korean Vietnam veterans were lower than those reported for other occupationally or environmentally exposed groups and US Vietnam veterans, and their use as an objective marker of Agent Orange exposure may have some limitations. The unit of deployment, duration of deployment, year of first deployment, military rank, perceived self-reported exposure, and proximity-based exposure to Agent Orange were not associated with TCDD levels in Korean Vietnam veterans. Age, body mass index and smoking also were not associated with TCDD levels.

Polymorphism of the aryl-hydrocarbon receptor gene in intron 10 of human cancers

Polychlorinated dibenzo-p-dioxins (PCDDs) and related halogenated aromatic hydrocarbons (e.g., PCDFs), often called "dioxins", are ubiquitously present environmental contaminants. Some of them, notably 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), are among the most toxic synthetic compounds known. The biological effects of dioxins are mediated via the aryl hydrocarbon receptor (AhR). Mutations in the AhR transactivation domain are linked to sensitivity to the acute lethality of TCDD. We present here a study of AhR gene polymorphism in normal and cancer human tissues affecting pre-mRNA splicing in the AhR gene-coding transactivation domain region (exon 10, intron 10, exon 11 region), previously shown to be associated with AhR dysfunction. We tested 126 pairs of normal and cancer tissue samples from liver, lung, stomach, kidney, mucous, breast, and pancreas of 49 males and 77 females (45-70 years of age). We used in vitro splicing assay, RT-PCR and sequencing methods. Our results showed that in an in vitro system it is possible to reconstitute cellular pre-mRNA splicing events. Tested cancer tissues did not contain mutations in the AhR transactivation domain region when the DNA sequences were compared with those from normal tissues. There were also no differences in AhR mRNA splice variants between normal and malignant breast tissues and no polymorphisms in the studied regions or cDNA.

Fatores ambientais e endometriose / Environmental factors and endometriosis

A endometriose representa uma afecção ginecológica comum, atingindo de 5 por cento-15 por cento das mulheres no período reprodutivo e até 3 por cento-5 por cento na fase pós-menopausa. Essa doença é definida pelo implante de estroma e/ou epitélio glandular endometrial em localização extrauterina, podendo comprometer diversos locais. Humanos e animais são expostos diariamente a poluentes químicos que têm a capacidade de influenciar negativamente processos fisiológicos e, potencialmente, causar doenças, dentre elas a endometriose. Com esta revisão tivemos por objetivo relacionar a influência dos fatores ambientais e dietéticos na gênese da endometriose. O mecanismo pelo qual a dioxina e seus símiles (TCDD/PCBs) atuam na alteração da fisiologia endometrial permanence incerta e é especulativa devido à dificuldade em se avaliar a exposição na vida intraútero, infância e vida adulta e suas reais consequências, além das limitações de sua reprodução in vitro. Devemos entender melhor o mecanismo de ação desses poluentes amibentais não só na saúde reprodutiva, mas na saúde em geral do indivíduo, para se promover estratégias de prevenção que devem incluir não só a educação populacional, mas o estabelecimento de limites de exposição, técnicas menos poluentes e melhor aproveitamento dos nossos recursos naturais.

Endometriosis represents a common gynecological condition affecting 5 percent-15 percent of childbearing age women and up to 3 percent 5 percent of post-menopausal women. This disease is defined by the presence of stromal and/or endometrial glandular epithelium implants in extra-uterine locations possibly compromising several sites. Humans and animals are daily exposed to chemical pollutants that could adversely influence physiological processes and potentially cause diseases, including endometriosis. In this review, the authors aimed at settling the influence of environmental and dietary factors on endometriosis pathogenesis. The mechanism by which dioxin and its similes (TCDD/PCBs) act changing the endometrial physiology remains uncertain and is speculative due to the difficulty in assessing the exposure over intrauterine life, childhood and adulthood and its actual consequences, in addition to the limitations to its in vitro reproducibility. We need to better understand the mechanism of action of these environmental pollutants, not only on reproductive health, but also on overall health of individuals and so prevention strategies, including not only population education, but setting exposure limits, less polluting techniques and a better use of our natural resources, could be promoted.

Main Sources Analysis of Dioxins Pollution in Fishes by Principal Component Analysis / 环境与健康杂志

Objective To analyze the main sources of dioxins pollution in fishes samples. Methods The principal components analysis was employed to identify different dioxin emission sources data and to analyze the environmental and aquatic samples. The Principal Component Analysis seems to be a powerful tool for source identification with the ratio of each concentration of the 2,3,7,8-subtituted congener to the concentration of the total 2,3,7,8-subtituted congeners. Results The result obtained from Principal Component Analysis showed that there were different dioxin compositions between chemical emission sources and other emission sources. Conclusion The pollution sources of PCDD and PCDF polluted aquatic life from different countries,regions are not the same.

Determination of dioxins in human hair: Estimation of external and internal exposure to dioxins

<p><b>OBJECTIVES</b>To clarify the origin of dioxin and related compounds (dioxins) in human hair, we determined the amounts of adsorbed dioxins in human hair, and the distribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in rats.</p><p><b>METHODS</b>Human hair specimens, packed in a glass column, were exposed to ambient air that was introduced into the column with an air pump for 24 h. Rats were administered TCDD by gavage at doses of 0.2, 0.8, and 1.6 μg/kg body weight. Four weeks after TCDD administration, hair from the back, serum, and adipose tissue were removed under diethyl ether anesthesia. The amounts of dioxins in these samples were analyzed by high resolution gas chromatography with mass spectroscopy.</p><p><b>RESULTS</b>Exposure of the hair specimens to ambient air for one day increased the total toxic equivalent (TEQ) value by 51%. In TCDD-treated rats, the amount of TCDD in hair increased in a dose-dependent manner, and showed a significant positive correlation with that in adipose tissue.</p><p><b>CONCLUSIONS</b>Human hair was found to retain dioxins by both internal and external exposure, and the contribution of external exposure was estimated to be about 40% of the TEQ.</p>

Determination of Dioxins in Human Hair: Estimation of External and Internal Exposure to Dioxins

Objectives: To clarify the origin of dioxin and related compounds (dioxins) in human hair, we determined the amounts of adsorbed dioxins in human hair, and the distribution of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in rats. Methods: Human hair specimens, packed in a glass column, were exposed to ambient air that was introduced into the column with an air pump for 24 h. Rats were administered TCDD by gavage at doses of 0.2, 0.8, and 1.6 μg/kg body weight. Four weeks after TCDD administration, hair from the back, serum, and adipose tissue were removed under diethyl ether anesthesia. The amounts of dioxins in these samples were analyzed by high resolution gas chromatography with mass spectroscopy. Results: Exposure of the hair specimens to ambient air for one day increased the total toxic equivalent (TEQ) value by 51%. In TCDD-treated rats, the amount of TCDD in hair increased in a dose-dependent manner, and showed a significant positive correlation with that in adipose tissue. Conclusions: Human hair was found to retain dioxins by both internal and external exposure, and the contribution of external exposure was estimated to be about 40% of the TEQ.