电子受体类型对聚磷污泥胞外聚合物的影响研究

采用3种电子受体(硝氮、亚硝氮、氧),在SBR反应器中分别驯化了具有稳定除磷能力的聚磷污泥。对比研究了不同聚磷污泥胞外聚合物(EPS)的组分与含量,结合三维荧光光谱对EPS中有机物质进行分析。研究表明,以硝氮、亚硝氮为电子受体的聚磷污泥EPS平均浓度较为接近,分别为115.6mg/gVSS、133.5 mg/gVSS,由厌氧段至缺氧段,EPS总浓度有所下降。以氧为电子受体聚磷污泥的EPS平均浓度相对较高,为194.5 mg/gVSS,由厌氧段至好氧段,EPS总浓度略有升高。不同聚磷污泥的EPS组分均以胞外蛋白为主,占EPS总量的53%~65%,多糖与核酸占EPS总量28%~34%、5%~7%。三维荧光光谱显示3种聚磷污泥EPS均具有芳香结构蛋白质、可溶性代谢物的荧光峰,另外,以硝氮为电子受体的聚磷污泥还具有明显的腐殖酸类物质的荧光峰。研究结果表明电子受体对聚磷污泥EPS的组分、浓度、有机质类别有一定的影响。     

Tissue distribution of perfluoroalkyl acids and health status in wild Mozambique tilapia (Oreochromis mossambicus) from Loskop Dam, Mpumalanga, South Africa

This study examined concentrations of 15 perfluoroalkyl acids (PFAAs) in tissues from male Mozambique tilapia (Oreochromis mossambicus) collected at Loskop Dam, Mpumalanga, South Africa in 2014 and 2016. Nine of the 15 PFAAs were detected frequently and were included in statistical analysis and included two of the most commonly known PFAAs, perfluorooctanesulfonic acid (PFOS) (median, 41.6 ng/g) and perfluorooctanoic acid (PFOA) (median, 0.0825 ng/g). Of the tissues measured, plasma (2016 and 2014 median, 22.2 ng/g) contained the highest PFAA burden followed by (in descending order): liver (median, 11.6 ng/g), kidney (median, 9.04 ng/g), spleen (median, 5.92 ng/g), adipose (median, 2.54 ng/g), and muscle (median, 1.11 ng/g). Loskop Dam tilapia have been affected by an inflammatory disease of the adipose tissue known as pansteatitis, so this study also aimed to investigate relationships between PFAA tissue concentrations and incidence of pansteatitis or fish health status. Results revealed that healthy tilapia exhibited an overall higher (p-value < 0.05) PFAA burden than pansteatitis-affected tilapia across all tissues. Further analysis showed that organs previously noted in the literature to contain the highest PFAA concentrations, such as kidney, liver, and plasma, were the organs driving the difference in PFAA burden between the two tilapia groups. Care must be taken in the interpretations we draw from not only the results of our study, but also other PFAA measurements made on populations (human and wildlife alike) under differing health status.     

Legal aspects of pesticides and toxic substances testing requirements

Abstract

The United States Environmental Protection Agency administers several laws and progrms through which it reviews the hazard potential of pesticides and other toxic substances which may present a risk to human health or the environment. The Agency's ability to assess hazard as required by law depends in part on test data developed through testing standards in Agency regulations. In reviewing the Agency's actions in this regard, the courts emphasize the importance of reasoned regulatory decisions. The legal requirements to assess risk and provide reasoned decisions in this regard establish the legal importance of testing guidelines and test data, and indicate that sound test methodology is as important legally as it is scientifically.     

Simulation of a Hazardous and Noxious Substances (HNS) spill in the marine environment: Lethal and sublethal effects of acrylonitrile to the European seabass

Despite the extensive maritime transportation of Hazardous and Noxious Substances (HNS), there is a current lack of knowledge on the effects posed by HNS spills on the marine biota. Among the HNS identified as priority, acrylonitrile was selected to conduct ecotoxicological assays. We assessed the acute and subletal effects of acrylonitrile in seabass, followed by a recovery phase to simulate the conditions of a spill incident. The work aimed at testing a broad range of biological responses induced by acrylonitrile. Sublethal exposure to the highest two doses increased the fish mortality rate (8.3% and 25% mortality in 0.75 and 2 mg L⁻¹ acrylonitrile concentrations), whereas no mortality were observed in control and 0.15 mg L⁻¹ treatments. Additionally, important alterations at sub-individual level were observed. Acrylonitrile significantly induced the activities of Catalase– CAT and Glutathione S-Transferase – GST; and the levels of DNA damage were significantly increased. Conversely, Superoxide Dismutase– SOD – activity was found to be significantly inhibited and no effects were found on Lipid Peroxidation– LPO and ethoxyresorufin O-deethylase – EROD – activity. Following a 7 d recovery period, the levels of CAT, GST and EROD fell to levels at or below those in the control. In the 2 mg L⁻¹ group, SOD remained at the levels found during exposure phase. This study has gathered essential information on the acute and subletal toxicity of acrylonitrile to seabass. It also demonstrated that 7 d recovery allowed a return of most endpoints to background levels. These data will be useful to assist relevant bodies in preparedness and response to HNS spills.     

全球地表水中全氟和多氟烷基化合物污染特征演替

综述了全氟和多氟烷基化合物（PFASs）在国内外地表水环境中的空间分布及污染特征,总结归纳了PFASs的来源和特征变化趋势。针对地表水中PFASs的监测种类、监测技术及风险评估等方面存在的问题,提出未来需加强日常监测,重点加强对水环境中新型PFASs的关注;针对流域中不同种类PFASs建立高特异性、高灵敏度监测新技术;筛选适合的水生生物作为环境污染指示物以应用于新污染物的评估等建议。为今后我国地表水环境 PFASs污染的现状调查及治理工作提供确实可行的科学参考。     

长江流域全氟化合物污染态势与生态效应

简述了PFASs在长江流域上、中、下游水环境中的空间分布格局和时间变化趋势，探讨了其生物蓄积效应、淡水生物毒性效应和生态风险评价。指出，PFASs广泛赋存于长江流域从上游至下游的干流和支流及湖泊之中，其平均值低于我国其他主要流域；PFOA在长江流域内环境浓度最高，而PFOS在近10年环境管控措施下浓度降至极低，PFBS、PFBA和PFHxA等短链物质正作为替代物使用，可能在未来出现升高趋势。长江流域内水生动物（包括食用鱼类）能够从环境中富集PFASs并通过食物链传输，在其血液、肌肉和内脏中蓄积。虽然目前长江流域生态风险评价表明PFASs总体上风险为低级，但局部高浓度地区仍可能对敏感生物造成基因表达受损等毒性效应。     

美国化学物质数据报告制度的经验和启示

回顾了美国《有毒物质控制法》(TSCA)中现有化学物质数据报告(CDR)制度的历史背景。介绍了CDR制度的基本内容、数据质量保证、主要修订情况,以及2012年CDR上报的化学物质数据信息汇总分析情况。针对2016年开展的新一轮CDR数据报告,总结了其最新的变化和具体要求。从建立化学物质信息收集制度、对现有化学物质进行分级管理、重点关注化学物质用途划分和归类,以及建立数据库和信息系统等4个方面,探讨了CDR制度对我国化学品环境管理的启示。     

Source apportionment of perfluoroalkyl substances in surface sediments from lakes in Jiangsu Province, China: Comparison of three receptor models

Receptor models have been proved as useful tools to identify source categories and quantitatively calculate the contributions of extracted sources.In this study,sixty surface sediment samples were collected from fourteen lakes in Jiangsu Province,China.The total concentrations of C_4–C_(14)-perfluoroalkyl carboxylic acids and perfluorooctane sulfonic acid(∑_(12)PFASs) in sediments ranged from 0.264 to 4.44 ng/g dw(dry weight),with an average of 1.76 ng/g dw.Three commonly-applied receptor models,namely principal component analysis-multiple linear regression(PCA-MLR),positive matrix factorization(PMF) and Unmix models,were employed to apportion PFAS sources in sediments.Overall,these three models all could well track the ∑_(12) PFASs concentrations as well as the concentrations explained in sediments.These three models identified consistently four PFAS sources:the textile treatment sources,the fluoropolymer processing aid/fluororesin coating sources,the textile treatment/metal plating sources and the precious metal sources,contributing 28.1%,37.0%,29.7% and 5.3% by PCA-MLR model,30.60%,39.3%,22.4% and 7.7% by PMF model,and 20.6%,52.4%,20.2% and 6.8% by Unmix model to the ∑_(12) PFASs,respectively.Comparative statistics of multiple analytical methods could minimize individual-method weaknesses and provide convergent results to enhance the persuasiveness of the conclusions.The findings could give us a better knowledge of PFAS sources in aquatic environments.     

Radiosynthesis of perfluorooctanesulfonate (PFOS) and perfluorobutanesulfonate (PFBS), including solubility, partition and adhesion studies

Here, we describe for the first time the synthesis of [³⁵S] PFOS and [³⁵S] PFBS with sulfur-35 enriched sulfur dioxide as the radiolabelled reagent, resulting in 2.5 and 2.3 mCi of product, respectively. Basic information concerning the physicochemical properties of perfluorooctanesulfonate (PFOS), perfluorobutanesulfonate (PFBS) and perfluorooctanoic acid (PFOA) are still limited. Hence, we utilized these radiolabelled perfluoroalkanesulfonates (PFSAs), as well as carbon-14 labelled perfluorooctanoic acid ([¹⁴C] PFOA) to determine some basic characteristics of physiological and experimental significance.The solubility of PFOS in buffered aqueous solutions at pH 7.4 was found to be severely reduced in the presence of potassium and sodium ions, which, however, did not reduce the solubility of PFOA or PFBS. PFOS was found to adhere to a small extent to polypropylene and polystyrene, whereas no such adhesion of PFOA or PFBS was detected. The extents of adhesion of PFOS and PFOA to glass were found to be 20% and 10%, respectively. For the first time, the partition coefficients for PFOS, PFBS and PFOA between n-octanol and water were determined experimentally, to be −0.7, −0.3, and 1.4, respectively, reflecting the difference in the amphiphilic natures of these molecules.     

Association of serum levels of perfluoroalkyl substances with gestational diabetes mellitus and postpartum blood glucose

This study was conducted to examine the association of perfluoroalkyl substance(PFAS)exposure with gestational diabetes mellitus(GDM) risk and postpartum fasting blood glucose.We used a 1:2 matched case–control study with 84 GDM subjects and 168 healthy pregnant women from Beijing, China. The maternal blood was collected at 1–2 days before delivery, and eight linear isomers and fourteen branched isomers were determined in maternal serum.Logistic regression analyses were performed to evaluate the associations after adjusting for potential confounders. The median of the sum of levels of total PFASs was 4.24 ng/m L with a interquartile range(IQR) of 2.82–6.54 ng/m L. Although maternal PFAS exposure was not associated with risk of GDM, significant positive associations were observed between evaluated exposure to specific PFAS congeners and increasing blood glucose. The odds ratio(ORs) of the highest category of postpartum fasting blood glucose for perfluoro-1-metylheptylsulfonat(1 m-PFOS), perfluoro-3/4-metylheptylsulfonat(3 m+4 m-PFOS), perfluoro-5-metylheptylsulfonat(5 m-PFOS), and perfluorohexane sulfonate(PFHx S) were 2.03(95% CI: 1.09–3.77), 1.93(95% CI:1.04–3.58), 2.48(95% CI: 1.33–4.65), and 2.26(95% CI: 1.21–4.21), respectively, suggesting negative effects of maternal exposure to specific PFAS compounds on glucose metabolism.