The biogeochemistry of selenium in Sunan grassland,Gansu, Northwest China,casts doubt on the belief that Marco Polo reported selenosis for the first time in history

In order to clarify the historic academic problem of whether or not livestock poisoning in ancient Suzhou of Northwest China, recorded by Marco Polo in 1295, was selenosis, this study deals with the biogeochemistry of selenium in Sunan County in the Hexi Corridor, which is part of ancient Suzhou in China. It was found that quite a number of farm animals had suffered from intoxication and died as a result of grazing poisonous grasses, mostly Oxytropis DC, Stellera chamaejasme, and Achnatheru inebrians. Toxic symptoms of livestock grazing on Oxytropis DC are similar to those of selenium toxicity, for instance, hair loss and hoof lesions as described by Marco Polo. Therefore, we thought that toxic grass, probably Oxytropis DC, led to the intoxication of livestock recorded by Marco Polo. Average Se concentrations in two members of this species were 0.112 +/- 0.038 mg/kg for the root of Oxytropis glabra, 0.102 +/- 0.027 mg/kg for the stem and leaf of Oxytropis glabra, and 0.066 +/- 0.009 mg/kg for Oxytropis ochrocephala. The average soil selenium concentration was 0.205 +/- 0.127 mg/kg on grassland producing Oxytropis glabra and 0.152 +/- 0.024 mg/kg on grassland producing Oxytropis ochrocephala. The average Se concentration in other plants was 0.076 mg/kg in the root of Ephedra monosperma Mey, 0.029 mg/kg in the root of Rheum palmatum, 0.031 mg/kg in the root of Stellera chamaejasme, 0.037 mg/kg in Achnatherum inebrians, and 0.067 mg/kg in forage grass (Achnatherum splendens ohwi). Selenium concentrations in soils and plants in Sunan County are far less than the thresholds causing selenium toxicity in livestock. As a result, this study concludes that the livestock poisoning recorded by Marco Polo in 1295 might not have been selenosis.     

Health risks of residential wood heat

The resurgence in the use of wood in the United States for residential heating has been accompanied by a dramatic increase in deaths and injuries from residential fires. Toxic materials present in woodsmoke also appear to present a significant public health hazard. As a result of these factors, production of residential wood heat can be up to two orders of magnitude more hazardous than generation of an equivalent amount of electric energy at a coal-fired power plant. Proper care in installation and operation of wood stoves, as well as technological innovations that control wood-stove emissions, can greatly reduce the health and safety hazards of residential heating with wood.     

高卤染料废水采用UV/SO32-工艺减毒过程中的中间产物及其毒性变化规律研究

染料废水含有大量难降解有机污染物,其中的有机卤代物通常具有较大的毒性和生态风险,但这类物质在常规的生物处理和化学处理工艺中的去除效果不佳。针对染料废水的脱卤困境,研究采用UV/SO₃^2-高级还原工艺对染料废水进行还原脱卤。在初始pH为8.5,SO₃^2-投加量为40 mmol·L^-1的条件下,废水中52.2%的可吸附有机卤素（adsorbable organic halogens,AOX）可以在反应开始6 h后被去除,更高的初始pH和更大的SO₃^2-投加量均有利于提升AOX的去除率。中间体的定性和半定量研究揭示了染料废水中部分氯代苯胺类物质的还原脱卤路径,发现苯胺很可能是这些物质还原脱卤的主要产物。废水中有机物的平均预测毒性揭示了还原过程中废水急性毒性的变化趋势。这一趋势与T₃发光杆菌和小球藻的急性毒性评价结果一致。此外,染料废水的AOX浓度与T₃发光杆菌的发光抑制率呈现正相关关系,而且染料废水经过还原脱卤后,尽管水中盐含量有所增加,其EC₅₀由1.26 mg·L^-1增加到5.94 mg·L^-1,这也证明了还原脱卤过程可以降低出水的急性毒性。因此,UV/SO₃^2-过程可以通过对水中有机卤代物的还原脱卤降低出水中的AOX,降低废水急性毒性和生态风险。     

孕期和哺乳期环境剂量氯氰菊酯暴露对子代雄性小鼠青春期启动的影响

氯氰菊酯（cypermethrin,CP）是一种应用广泛的拟除虫菊酯类农药,作为潜在的环境污染物和内分泌干扰物,其围产期暴露对子代具有一定的毒性作用。为探究孕期和哺乳期氯氰菊酯环境剂量暴露对子代雄性小鼠青春期启动的影响,将ICR小鼠在妊娠第6天至子代出生后（postnatal day,PND）第21天,暴露于0、6.7、20和60 μg·kg^-1·d^-1氯氰菊酯,观察子代雄性小鼠青春期启动情况,同时分别检测PND22小鼠下丘脑、垂体、睾丸组织中GnRH、KISS-1、CGα、LHβ、FSHβ、StAR和CYP1A1的表达水平以及血清中促性腺激素释放激素、卵泡刺激素、黄体生成素和睾酮的含量。检测PND21 ICR小鼠下丘脑和睾丸组织体外暴露于0、6.7、20和60 μg·L^-1氯氰菊酯后丙二醛、总谷胱甘肽、NO含量和总超氧化物歧化酶活性。结果表明,在60 μg·kg^-1·d^-1的氯氰菊酯暴露剂量下,子代雄性小鼠青春期启动日龄减少（P<0.01）;20～60 μg·kg^-1·d^-1显著诱导促性腺激素释放激素、黄体生成素和睾酮分泌（P<0.05）;6.7～60 μg·L^-1体外暴露24 h会对下丘脑和睾丸组织产生氧化损伤。孕期和哺乳期氯氰菊酯环境剂量暴露可导致子代雄性小鼠青春期启动提前,下丘脑-垂体-睾丸轴相关激素分泌总体上调。本研究结果为准确、全面评估拟除虫菊酯类杀虫剂的环境安全与健康风险提供科学依据和理论基础。     

Determination of Toxic Pollutants in Water Using A Marine Phytoplankton Dunaliella Bioculata and Doppler Laser Velocimetry

This paper reports an experimental study of the response of the unicellular flagellated algae Dunaliella bioculata to toxic pollutants in water using the 'Doppler laser velocimetry' method. the response to toxic pollutants was encouraging and indicates that Dunaliella bioculata is a good biological model for the detection of toxic pollutants in water.     

Removal of arsenic in tailings by soil flushing and the remediation process monitoring

In order to investigate the optimum conditions for the application of soil flushing of arsenic, a batch test was carried out using EDTA at various concentration and pH levels. Based on the optimum condition derived from the batch test, a column test was conducted to examine the feasibility of the soil-flushing technology under field-equivalent conditions. In this column test, a low flushing solution flow rate showed a significantly higher As removal efficiency (71.6%) than a high flow rate (56.3%). TCLP (toxicity characteristic leaching procedure) and a seed germination test were carried out to monitor the toxicity both during and after the treatment. The finally treated tailings were shown to be significantly remediated, having a reduced toxicity by both the TCLP and seed germination tests.     

Comparative Toxicities of Polar and Non-Polar Organic Fractions From Sediments Affected By the Exxon Valdez Oil Spill in Prince William Sound, Alaska

Standardized tests were applied to aromatic and polar fractions of sediment extracts to determine whether polar constituents or oxidative degradation products contributed significantly to the toxicity of sediments oiled by the Exxon Valdez spill. Intertidal sediment and pore-water samples were collected in September 1990 from two heavily oiled sites and an unoiled site in Prince William Sound (PWS). Methylene chloride extracts from these samples were fractionated by liquid chromatography into aliphatic, aromatic and polar fractions, and the aromatic and polar fractions were tested for toxicity using the Microtox^R test, bivalve larval mortality and development (Mytilus); several measures of genotoxicity in Mytilus, including SOS Chromotest^R, anaphase aberrations and sister chromatid exchange; and survival, anaphase aberrations and teratogenicity in coho salmon (Onchorhynchus kisutch). Microtox^R and SOS Chromotest^R protocols were applied in a screening mode to all samples, whereas other tests were applied only to selected fractions from two sites. Samples from Bay of Isles (oiled) were consistently more toxic (usually only 2 to 5-fold) than the Mooselips Bay (unoiled) samples, which gave very low responses in all tests. for both sites, however, responses to polar and aromatic fractions were about the same in most tests, suggesting that while the overall toxicity of the oil was low in these samples, at least part of that toxicity was derived from polar constituents. Compared to the parent hydrocarbons, polar oxidation products partition preferentially into pore-water and are more rapidly diluted and dispersed in the water column. These results suggest that polar oxidation products of petroleum hydrocarbons pose little risk to marine organisms, except possibly for infauna continuously exposed to pore-water in heavily oiled sediments. Independent surveys showed that sediment toxicity in PWS declined during 1989-1991 to near background levels, in accord with previous understanding of oil weathering and toxicity.     

咪唑型离子液体对小鼠的急性毒性

采用寇氏改良法研究了咪唑型离子液体对小鼠的急性毒性,并考察了烷基侧链长度对其毒性的影响,同时采用HE染色法观察了其对小鼠肝脏的毒性.结果表明,4种咪唑型离子液体([C10mim]Br、[C12mim]Br、[C14mim]Br和[C18mim]Br)对小鼠肝脏均有损伤,其LD50值在98.91～220.16mg·kg-1之间,为中等毒性.咪唑型离子液体对小鼠的急性毒性与其侧链长度有关,当碳链长度为14时,其毒性最强.     

生物活性炭法深度处理印染废水及其生物毒性的表征

采用负载经驯化后微生物的活性炭深度处理实际印染废水,研究生物活性炭系统中存在的生物相及其降解有机污染物的作用,并表征了处理后印染废水的生物毒性。结果表明,生物相中含有草履虫、轮虫及钟虫等原生动物。随着运行次数的增加,活性炭反应器在运行5次后出水的COD、NH3-N及色度去除率骤降,但是生物活性炭处理后出水的COD、NH3-N及色度去除率缓慢下降。生物活性炭能很好地降解印染废水中的苯酚类和稠环芳烃污染物。本研究中生物活性炭反应器对氨氮和COD的去除符合一级动力学方程,去除动力学常数分别为1.02和0.96。经过生物活性炭的处理可以将印染废水的生物毒性降到适于小球藻生长的水平。     

采用水解酸化-复合好氧处理制药工业废水的工艺评价

以制药工业综合废水处理为例对其采用的两级水解酸化复合好氧工艺的处理效果进行评估。按常规指标进行评估,该工艺对于制药综合废水的处理效果达到了设计目的,COD去除率可达到78.2%以上,NH4+-N的去除率达到99.3%,出水质量基本满足\"污水综合排放标准(GB8978-1996)\"二级标准和\"辽宁省污水综合排放标准(DB21.1627-2008)\";急性毒性的检测表明,经过该工艺处理后出水为低毒性;三维荧光谱分析(EEM)表明,制药综合废水经生物处理后的可溶性有机物中仍然存在难降解物质,建议增加物化处理以提高处理效果;并且制药废水经处理后的出水中的盐度对排入的生态系统存在风险,建议纳入排放标准以加强管理。