深圳主要河流中雌激素污染调查

调查了深圳市10条主要河流雌激素污染现状,结果表明,双酚A在深圳市河流中28个监测点中27个点有检出,检出率96.4％,质量浓度为未检出～6.042 μg/L;17β雌二醇(E2)在深圳市河流中28个监测点中8个点有检出,检出率28.6％,质量浓度为未检出～0.011 6μg/L,能检出的17β雌二醇(E2)值大都在0.001 5μg/L～0.003 9 μg/L之间;雌三醇(E3)仅在1个监测点(新洲河河口)有检出,对壬基酚均未检出.     

镉、汞、锌3种重金属的雌激素样作用（Estrogenic Activity of Cadmium, Mercury, and Zinc）

为探讨镉、汞、锌3种重金属的雌激素样作用,采用双杂交酵母法测定了醋酸镉、氯化汞、醋酸锌单独作用时对重组基因酵母β-半乳糖苷酶诱导活性的EC50值.实验结果表明,醋酸镉浓度为1.0×10-5mol·L-(1实验浓度范围10-7~10-2mol·L-1),氯化汞浓度为5.0×10-7mol·L-(1实验浓度范围10-9~10-5mol·L-1),醋酸锌浓度为1.0×10-4mol·L-(1实验浓度范围10-9~10-2mol·L-1)时对酵母β-半乳糖苷酶诱导活性最大,分别达到1.3、0.95和1.1U.不能求出镉、汞、锌单独作用时对β-半乳糖苷酶诱导活性的EC50值.一味计算EC50值不仅难以评价重金属的雌激素活性,而且限制重组受体基因酵母法的普遍运用.一些重金属通过MCF-7细胞法(E-screen)呈阳性,通过重组hERα酵母法YES检测呈阴性,有可能是重金属通过与ERβ作用而产生效应.若构建出含ERβ基因的双杂交酵母菌株,与现有的方法互补将能完善环境雌激素的体外测评系统.     

Uptake of 17β-estradiol and biomarker responses in brown trout (Salmo trutta) exposed to pulses

In streams, chemicals such as 17β-estradiol (E2) are likely to occur in pulses. We investigated uptake and biomarker responses in juvenile brown trout (Salmo trutta) of 3- or 6-h pulses of concentrations up to 370 ng E2 L⁻¹. Uptake by the fish was estimated from disappearance of E2 from tank water. A single 6-h pulse of 370 ng E2 L⁻¹ increased the plasma vitellogenin concentration, liver Erα- and vitellogenin-mRNA. Exposure to 150-160 ng E2 L⁻¹ for 6 h increased vitellogenin in one experiment but not in another. Two 6-h pulses had a larger effect one pulse. Brown trout in the size range 24-74 g took up E2 linearly with time and exposure concentration with a concentration ratio rate of 20.2 h⁻¹. In conclusion, the threshold for induction of estrogenic effects in juvenile brown trout at short term pulse exposure appears to be in the range 150-200 ng E2 L⁻¹.     

An on-farm survey of spatial and temporal stratifications of 17β-estradiol concentrations

17β-estradiol (E2) is a natural estrogenic hormone found in animal manure and urine, which may cause endocrine disruption in sensitive organisms. 17β-Estradiol has been widely detected in the environment, and animal agriculture may be an important source. The objectives of this study were to investigate the potential sources and/or spatial and temporal characteristics contributing to detections of E2 at the farm-scale. Soil cores, segmented into 0.15 m increments, were taken down to the water table from four locations (three potential E2 sources and one control) at or around a swine (Sus scrofa domesticus) farm on five different dates between 2006 and 2007. Estradiol was quantified in the soil-water extracts using liquid chromatography-with tandem mass spectrometry (LC/MS/MS) analysis. Estradiol detections were widespread and found in 128 out of 345 extractions (37%). Concentrations ranged from 0 to 1910 ng L⁻¹ (porewater equivalents). A location that received field application of manure had significantly lower E2 concentrations compared to other locations. Also, the spring 2007 E2 concentrations were significantly higher than all other sample dates, perhaps related to climatic and hydrological events. Results suggested E2 was not directly related to manure sources, but was widespread in this environment. Where E2 was detected, highest concentrations favored the upper profile, while the greatest frequency of detections was in the lower profile and near the water table. Detections of E2 were associated with high organic mater contents in the upper profile and high sand contents in the lower profile. The study suggests that E2 is widespread in some soil environments, raising questions as to the source and mechanisms that facilitate its transport and mobility.     

Evaluation of the fish short term reproduction assay for detecting endocrine disrupters

In a fish testing strategy, positive results of the fish short term reproduction assay (FSTR), often trigger a definitive test like the fish sexual development test (FSDT) or the fish full life cycle test (FFLC), entailing ethical and economic problems. This study analysed 137 studies encompassing 35 chemicals with different modes of actions (MOAs). Variability is quantified for MOA endpoints vitellogenin (VTG) and secondary sex characteristics (SSCs) as well as for apical endpoints. Two MOA endpoints could indicate estrogenic, anti-estrogenic, androgenic, anti-androgenic and steroidogenesis activities. Great variability, however, has been observed for chemicals with anti-androgenic and steroidogenesis activities, suggesting that TG229/230 may not be sensitive enough to detect these types of chemicals and may produce false negatives. Changes in apical endpoints like fecundity are not limited to endocrine disrupting chemicals (EDCs). Non-EDCs could induce the similar effects on these apical endpoints. If elucidating MOA is needed, targeted in vitro MOA tests are suggested. Positive in vitro MOA results trigger a definitive test, which could be used for confirmation of the MOA in vivo and for deriving a no observed effect concentration (NOEC). Based on positive MOA results of TG229, a definitive test such as the FSDT or the FFLC is still needed, because the current TG229 has limitation on the derivation of a NOEC. An extended TG229 with more power to detect reproduction effects, as recently proposed in the OECD test guideline program, would improve the possibility to derive a NOEC and increase its usefulness in risk assessment.     

Brief exposure to copper induces apoptosis and alters mediators of olfactory signal transduction in coho salmon

Pacific salmon are particularly susceptible to copper (Cu)-induced olfactory injuries that can ultimately inhibit neurobehaviors critical to survival. However, the molecular mechanisms underlying Cu-mediated olfactory impairment remain poorly understood. In the present study, we conducted a short-term Cu exposure at levels relevant to urban runoff (5, 25 and 50 ppb) , and investigated the roles of impaired olfactory signal transduction and induced apoptosis as underlying mechanisms of olfactory injury. Increased cell death in the olfactory epithelium was evident in coho receiving 4 h exposures to 25 and 50 ppb Cu. Expression of olfactory marker protein (omp), a marker of mature olfactory sensory neurons, also decreased at 50 ppb Cu. Immunohistochemical analysis of coho olfactory epithelium demonstrated a loss of type 3 adenylate cyclase (ACIII) in the apical olfactory epithelium cilia at all levels of Cu exposure, suggesting an inhibitory effect of Cu in olfactory signaling. Accompanying the loss of ACIII in Cu-exposed coho were reduced intracellular cyclic guanosine monophosphate (cGMP) levels in the olfactory rosettes. Collectively, these results support a linkage among the initial steps of olfactory signaling in Cu-induced salmon olfactory injury, and suggesting that monitoring olfactory cGMP levels may aid in the assessment of salmon olfactory injury.     

Assays of dioxins and dioxin-like compounds in actually contaminated soils using transgenic tobacco plants carrying a recombinant mouse aryl hydrocarbon receptor-mediated β-glucuronidase reporter gene expression system

The transgenic tobacco plant XD4V-26 carrying the recombinant mouse aryl hydrocarbon receptor XD4V-mediated β-glucuronidase (GUS) reporter gene expression system was used for assay of dioxins and dioxin-like compounds consisting of polychlorinated dibenzeno-p-dioxins, polychlorinated dibenzofurans, and coplanar polychlorinated biphenyls (Co-PCBs) in actually contaminated soils. The transgenic tobacco plant XD4V-26 showed a significant dose-dependent induced GUS activity when cultured on MS medium containing PCB126 [toxic equivalency factor (TEF) = 0.1]. In contrast, PCB169 and PCB180, which have 0.03 of TEF and unassigned TEF values, respectively, did not significantly induce GUS activity under the same conditions as with PCB126. When the tobacco plants were cultivated for up to 5 weeks on actually contaminated soils with dioxins and dioxin-like compounds collected from the periphery of an incinerator used for disposal of residential and industrial wastes, GUS activity in the leaves was dose-dependently increased. The plants clearly detected 360 pg-TEQ g^?1 of dioxins and dioxin-like compounds in this assay. There was a positive correlation between GUS activity and TEQ value of dioxins and dioxin-like compounds in the plants. This assay does not require any extraction and purification processes for the actually contaminated soil samples.     

Long-range transport of acidifying substances in East Asia—Part II: Source–receptor relationships

Region-to-grid source–receptor (S/R) relationships are established for sulfur and reactive nitrogen deposition in East Asia, using the Eulerian-type Community Multiscale Air Quality (CMAQ) model with emission and meteorology data for 2001. We proposed a source region attribution methodology by analyzing the non-linear responses of the CMAQ model to emission changes. Sensitivity simulations were conducted where emissions of SO₂, NO_x, and primary particles from a source region were reduced by 25%. The difference between the base and sensitivity simulations was multiplied by a factor of four, and then defined as the contribution from that source region. The transboundary influence exhibits strong seasonal variation and generally peaks during the dry seasons. Long-range transport from eastern China contributes a significant percentage (>20%) of anthropogenic reactive nitrogen as well as sulfur deposition in East Asia. At the same time, northwestern China receives approximately 35% of its sulfur load and 45% of its nitrogen load from foreign emissions. Sulfur emissions from Miyakejima and other volcanoes contribute approximately 50% of the sulfur load in Japan in 2001. Sulfur inflows from regions outside the study domain, which is attributed by using boundary conditions derived from the MOZART global atmospheric chemistry model, are pronounced (10–40%) over most parts of Asia. Compared with previous studies using simple Lagrangian models, our results indicate higher influence from long-range transport. The estimated S/R relationships are believed to be more realistic since they include global influence as well as internal interactions among different parts of China.     

Steroid estrogens, conjugated estrogens and estrogenic activity in farm dairy shed effluents

Agricultural wastes are a source of steroid estrogens and, if present, conjugated estrogens may add to the estrogen load released to soil and aquatic environments. Dairy shed effluent samples were collected from 18 farms for analysis of steroid estrogens by GC-MS, conjugated estrogens by LC-MS-MS, and estrogenic activity by E-screen in vitro bioassay. 17α-estradiol was found at highest concentrations (median 730 ng l⁻¹), followed by estrone (100 ng l⁻¹) and 17β-estradiol (24 ng l⁻¹). Conjugated estrogens (estrone-3-sulfate, 17α-estradiol-3-sulfate and 17β-estradiol-3,17-disulfate) were measured in most samples (12-320 ng l⁻¹). Median estrogenic activity was 46 ng l⁻¹ 17β-estradiol equivalents. Conjugated estrogens contributed up to 22% of the total estrogen load from dairy farming, demonstrating their significance. Steroid estrogens dominated overall estrogenic activity measured in the samples. Significantly, 17α-estradiol contributed 25% of overall activity, despite potency 2% that of 17β-estradiol, highlighting the importance in environmental risk assessments of this previously neglected compound.     

西藏中部河流、湖泊表层沉积物及其周边土壤重金属来源解析及风险评价

为了解西藏河流-湖泊体系沉积物重金属的污染特征、空间分布、潜在来源及生态风险,对西藏中部河流、湖泊表层沉积物及其周边土壤中As、Ba、Cd、Co、Cr、Cu、Hg、Mn、Mo、Ni、Pb、Sb、V、Zn、Al和Fe 16种重金属总量进行了分析,并利用主成分分析-绝对主成分分数-多元线性回归（PCA-APCS-MLR）受体模型定量解析了重金属的潜在来源.描述性统计分析表明,研究区As、Cd、Hg、Ni含量较高,其中Hg和As污染较为严重;富集因子、地累积指数、污染负荷指数均表明研究区Hg污染较重,其次是As、Cd、Ni;平均沉积物质量基准系数法与潜在生态风险指数结果表明,研究区受Hg、As、Cd、Ni污染,其中Hg污染较重.在空间分布方面,污染相对较重的区域主要集中在昂仁金错、堆龙曲及一些封闭型湖泊,其中As污染范围最广.PCA-APCS-MLR分析表明,沉积物重金属主要有3个来源,分别为自然来源、交通运输和大气传输以及地热活动和矿山开采等;Co、Cr、Cu、Hg、Mn、Ni、V、Zn、Al和Fe主要受自然因素影响;Ba、Mo、Pb主要受交通运输和大气传输影响;As几乎全部来自地热活动和矿山开采;Cd、Sb来源较为广泛,3个主要来源均有占比.土壤中Cd、Hg含量较高,可能受交通因素影响较大,同时还与工业排放后远距离输送所造成的大气污染有关.