我国饮用水水源内分泌干扰物的污染现状分析

我国作为饮用水水源的天然水体和部分饮用水水源地已受到内分泌干扰物的严重影响.文章分别从重金属类和有机类污染两个方面分析了我国饮用水源内分泌干扰物的污染现状,针对我国开展内分泌干扰物研究中存在的问题给出了建议对策并做出了展望.目前,我国七大水系以及华北、东南沿海地区的部分饮用水水源地都不同程度的受到了阿特拉津等有机氯农药...     

超声波-臭氧破解剩余污泥技术的初步研究

剩余污泥的处理与处置是我国和世界面临的重要环境课题.文章初步研究了臭氧、超声波及其组合工艺对剩余污泥的破解作用,考察了反应时间、臭氧流量、超声功率对污泥破解效果的影响.研究表明:臭氧流量为7I/min时破解效果最好,反应40min,SCOD、NH3-N、TN和TP分别比反应前提高了586%、178%、522%和1781...     

COD测定中氯离子干扰消除方法的探讨

通过对银盐抑制法、Cl2校正法、标准曲线法、密封消解法、干扰扣除法、HCl去除法6种方法进行试验对比,分析COD测定中可靠、无毒、适用的消除氯离子干扰的方法,并分析了这些方法的特点和可行性。     

Toxic effects on adult male zebrafish（Danio rerio） following co-exposure to tris-（2,3-dibromopropyl） isocyanurate and 17 β-estradiol

三-（2,3-二溴丙基）异氰脲酸酯（TBC）是近年来在环境中新检测到的一种杂环溴化阻燃剂,但其毒性效应尚不明确.我们以雄性斑马鱼为受试动物,开展了TBC和17β-雌二醇（E2）的复合暴露实验,以研究TBC潜在的致毒机制.结果显示TBC可显著抑制E2所引起的斑马鱼肥满度指数上升,并能改善E2暴露所造成的斑马鱼精子细胞比例降低和性腺发育迟缓;E2暴露可造成斑马鱼肝组织脂肪样病变,肝中MDA含量上升,但SOD活力没有显著改变;TBC复合暴露后,MDA含量呈现下降趋势,但鱼肝仍有明显的脂肪样病变,对肝脏中的SOD活力也没有显著影响;更重要的是,TBC可显著抑制E2单一暴露所诱导的雄鱼肝脏中卵黄蛋白原基因的表达,这些数据表明TBC具有明显的内分泌干扰效应.因此,需要进一步关注TBC这类杂环溴化阻燃剂对水环境的潜在危害.     

苏州河底泥3种内分泌干扰物的空间分布及环境风险

应用气相色谱质谱联用方法对苏州河及其支流底泥中3种环境内分泌干扰物壬基酚(NP)、辛基酚(4-t-OP)和双酚A(BPA)的含量进行检测和调查,结果表明,这3种物质在河流底泥中的浓度变幅分别为<1.0～5 800、<0.10～39和0.90～180μg.kg-1,空间分异显著.总体上看,底泥污染物浓度与河流周边人为活动密集程度有关:在苏州河上海市区段底泥的含量显著地高于上海远郊和江苏省内河段底泥含量;苏州河支流底泥中的含量显著高于苏州河干流底泥含量.苏州河及其支流底泥中这3种内分泌干扰物两两之间,存在显著正相关,说明其有相似的物源.以含量较高的壬基酚为例,进行底泥环境内分泌干扰物的风险评估,结果表明,除苏州河江苏省内吴家港桥段外,其它河段均存在潜在的生态毒害风险,需采取相应的防范措施.     

雌二醇对生物体内分泌系统毒性作用机制的研究

雌二醇可扰乱生物体内激素的正常分泌,对生物体生殖发育、神经系统及免疫系统造成损伤。本文通过查阅大量文献,结合临床试验及动物试验,研究了雌二醇干扰生物体内分泌系统的作用机制,结果发现:持续大剂量的雌二醇可显著扰乱动物体的内分泌系统;脂溶性的雌二醇不易被降解,在人体内也没有特定的代谢途径,因此微量的雌二醇即可在体内蓄积进而对机体造成损伤。     

The Hourglass: A Conceptual Framework for the Transport of Biologically Active Compounds from Agricultural Landscapes

Recent research has suggested that the fate of biologically active compounds (BACs) originating from point sources such as wastewater treatment plants is fundamentally different from that of similar compounds released from nonpoint sources through runoff from agricultural landscapes. Downstream from wastewater treatment plants, BACs will degrade via a variety of mechanisms; however, their concentration in the water adjacent to the point of discharge may not decrease over time, as the compounds are continually released. In contrast, in agricultural systems, BACs are episodically introduced to surface water during snowmelt and rainstorm events, and under these circumstances, may be found in water for only hours or days after a storm event. Recent research in our laboratories as well as others, has suggested that sediments play an important role in the persistence of herbicides and steroids in watersheds after nonpoint source loading events. Conceptually, the sediment serves as both a sink and a source, equilibrating with BACs during storm events then slowly releasing them back into the water over time, long after the initial pulse of chemicals has moved downstream.     

Spatial and Temporal Patterns of Endocrine Active Chemicals in Small Streams Indicate Differential Exposure to Aquatic Organisms

Alkylphenolic chemicals (APCs) and hormones were measured six times from February through October 2007 in three Minnesota streams receiving wastewater to identify spatial and temporal patterns in concentrations and in estrogen equivalency. Fish were collected once during the study to evaluate endpoints indicative of endocrine disruption. The most commonly detected APCs were 4‐tert‐octylphenol and 4‐nonylphenol and the most commonly detected hormones were estrone and androstenedione. Chemical concentrations were greatest for nonylphenol ethoxycarboxylates (NPECs) (5,000‐140,000 ng/l), followed by 4‐nonlylphenol and 4‐nonylphenolethoxylates (50‐880 ng/l), 4‐tert‐octylphenol and 4‐tert‐octylphenolethoxylates with concentrations as great as 130 ng/l, and hormones (0.1‐54 ng/l). Patterns in chemicals and estrogen equivalency indicated that wastewater effluent is a pathway of APCs and hormones to downstream locations in this study. However, upstream contributions can be equally or more important indicating alternative sources. This study indicates that aquatic organisms experience both spatially and temporally variable exposures in the number of compounds, total concentrations, and estrogenicity. This variability was evident in fish collected from the three rivers as no clear upstream to downstream pattern of endocrine disruption endpoints emerged.     

Assessment of Endocrine‐Disrupting Chemicals Attenuation in a Coastal Plain Stream Prior to Wastewater Treatment Plant Closure

The U.S. Geological Survey is conducting a combined pre/post‐closure assessment at a long‐term wastewater treatment plant (WWTP) site at Fort Gordon near Augusta, Georgia. Here, we assess select endocrine‐active chemicals and benthic macroinvertebrate community structure prior to closure of the WWTP. Substantial downstream transport and limited instream attenuation of endocrine‐disrupting chemicals (EDCs) was observed in Spirit Creek over a 2.2‐km stream segment downstream of the WWTP outfall. A modest decline (less than 20% in all cases) in surface water detections was observed with increasing distance downstream of the WWTP and attributed to partitioning to the sediment. Estrogens detected in surface water in this study included estrone (E1), 17β‐estradiol (E2), and estriol (E3). The 5 ng/l and higher mean estrogen concentrations observed in downstream locations indicated that the potential for endocrine disruption was substantial. Concentrations of alkylphenol ethoxylate (APE) metabolite EDCs also remained statistically elevated above levels observed at the upstream control site. Wastewater‐derived pharmaceutical and APE metabolites were detected in the outflow of Spirit Lake, indicating the potential for EDC transport to aquatic ecosystems downstream of Fort Gordon. The results indicate substantial EDC occurrence, downstream transport, and persistence under continuous supply conditions and provide a baseline for a rare evaluation of ecosystem response to WWTP closure.     

Fathead Minnow and Bluegill Sunfish Life‐Stage Responses to 17β‐Estradiol Exposure in Outdoor Mesocosms

Developmental and reproductive effects of 17β‐estradiol (E2) exposure on two generations of fathead minnows and one generation of bluegill sunfish were assessed. Fish were exposed to E2 for six continuous weeks in outdoor mesocosms simulating natural lake environments. First generation fish were exposed while sexually mature. Second generation fathead minnows were exposed either during early development, sexual maturity, or both stages. Multiple endpoints were measured to assess effects of E2 exposure on fecundity and fish health and development. Plasma vitellogenin concentrations were highly variable in all fish. Differences in egg production timing for both species indicate differences in fecundity between females exposed to E2 and controls. First generation fathead minnows exposed to E2 had lower body condition factors and reduced secondary sexual characteristic expression by males. Only a difference in relative liver weight was observed in second generation fathead minnows. First generation bluegill males exposed to E2 had significantly smaller testes compared to controls. Although fish response was highly variable, results indicate that exposure to E2 at environmentally relevant concentrations affect fathead minnow and bluegill sunfish health and development, which may have implications for the health and sustainability of fish populations. Furthermore, exposure timing and environmental factors affect fish response to E2 exposure.