Uptake and bioaccumulation of heavy elements by two earthworm species from a smelter contaminated area in northern Kosovo

As, Cd, Cu, Pb, Sb and Zn concentrations were determined in two earthworm species (Allolobophora rosea and Nicodrilus caliginosus) from a mining and industrial area in northern Kosovo and compared with their contents in the bulk soil and the main soil fractions. Earthworm specimens were collected at fifteen sites located at different distances from a Pb–Zn smelter along a gradient of decreasing contamination. Individuals of A. rosea and N. caliginosus showed similar tissue levels of As, Cd, Cu, Pb, Sb and Zn, suggesting that earthworm species belonging to the same eco-physiological group have a similar propensity to uptake and bioaccumulate heavy elements. Cd, Pb, Sb and Zn concentrations in both earthworm species were positively correlated with the respective total soil contents and generally decreased with distance from the smelter. The bioaccumulation factor (BAF) revealed that Cd and Zn were the only elements bioaccumulated by earthworms. The rank order of BAF values for both species was as follows: Cd > > Zn > > Cu > As = Pb = Sb. The absorption of Cd, Pb, Sb and Zn by earthworms mostly depended on the extractable, reducible and oxidable soil fractions, suggesting that the intestine is likely the most important uptake route. The extractable soil fraction constantly influenced the uptake of these heavy elements, whereas the reducible fraction was important mainly for Pb and Zn. The water soluble fraction had an important role especially for the most mobile heavy elements such as Cd and Zn, suggesting that dermal uptake is not negligible. As a whole, the analytical data indicate that soil fractionation patterns influence the uptake of heavy elements by earthworms, and the extractable fraction is a good predictor of heavy element bioavailability to these invertebrates in soil.     

噻嗪酮在水稻上的内吸输导作用和消解动态

 通过液相色谱检测结合生物活性测定与田间试验，证明水稻对噻嗪酮具有明显的内吸辅导作用。 稻茎可吸收和富集田水中的噻嗪酮，浓缩系数为2.4～3.5.施药187.5 g(ai)／ha后1～4周，噻嗪酮在稻茎中的消失率依次为73．30％、90.32％和95.01％。粗喷雾、泼浇、弥雾、毒土（有水层）等不同施药方式之间的防效差异不显著。试验表明，噻嗪酮对稻飞虱的高度生物活性，在水稻上的内吸作用和稻茎对田水中药剂的吸收、富集能力，是该药在田间表现长效的主要原因。     

水培条件下5种杂草植物对钴富集能力的比较

试验采用溶液培养的方法,比较5种杂草植物在不同浓度钴污染液(0、60、120、180、360 mg/kg)中对钴的吸收及富集能力.结果表明,①随处理浓度增加,各植物体内钴含量均增加,野茼蒿地上部钴含量增加量最多,当浓度为360 mg/kg时是对照的433倍;②各植物地上部、根部及单株钴积累量随钴浓度增大呈增大趋势,在浓度为360 mg/kg时,野茼蒿的单株积累量最高,可达13 021.33 μg,具有较强的钴积累能力;③分析5种植物对钴的吸收转运能力、富集特征得出,高钴浓度时野茼蒿的地上富集系数最大(25.95),并且地上部提取率最高(26.24％),龙葵、牛膝菊次之;中低浓度钴处理时牛膝菊转运系数最大可达3.86,其地上部富集系数也较高,野茼蒿和龙葵的转运系数虽次于牛膝菊,但其富集和提取能力均较突出.综上所述,野茼蒿、龙葵、牛膝菊可作为修复钴污染土壤的备选植物.     

河口海岸沉积物中多环芳烃的环境行为研究

多环芳烃（PAHs）是一种具有持久性、半挥发性、生物蓄积性和高毒性的环境污染物。河口海岸沉积物是PAHs重要的源和汇。PAHs在沉积物中环境行为的研究为其生态风险评估和污染治理措施提供重要的科学依据。本文综述了近年来对河口海岸沉积物中PAHs的吸附解吸、生物富集和生物降解等主要环境行为及其影响因素的研究,并提出了研究展望。     

夜间增温对小麦吸持铅素的影响

当前非对称气候变暖及部分农业土壤铅富集潜在影响我国小麦生产,揭示夜间增温对小麦吸持铅素及其分配的影响有助于确保粮食安全生产。利用田间被动式夜间增温系统设置不同铅浓度客土盆栽试验,研究小麦产量与地上部组织的生物量、铅含量与积累量、铅富集系数和迁移系数随温度变化的响应。结果表明,夜间增温显著增加小麦产量8.3%,却显著降低茎叶和地上部总干重;铅污染表现为负效应且随污染程度增加而加大。夜间增温显著降低地上部植株、籽粒与颖壳中铅含量,但对茎、叶中铅含量影响不大;分别显著降低籽粒中铅积累量7.6%(轻度污染)和6.8%(重度污染)、颖壳中铅积累量12.0%(无污染)和13.9%(重度污染)和全部污染处理下小麦地上部(14.0%~23.3%)、茎(22.5%~24.9%)、叶(17.9%~31.8%)中铅积累量。夜间增温显著降低无污染处理铅在茎、叶、籽粒和颖壳中的富集系数和轻污染处理铅在茎、籽粒和颖壳中的富集系数,但未显著影响重度污染处理铅在各器官中的富集系统。增温显著降低了全部污染处理中由茎向籽粒、颖壳转移的铅迁移系数。夜间增温有利于小麦生产且能降低铅胁迫农田粮食遭受铅污染的潜在风险。     

培养料中重金属对真姬菇产品质量安全的影响

研究表明，子实体中As、Hg、Pb、Cd4种重金属的浓度随着添加水平升高而增大．但是富集系数逐渐降低。通过对培养料中重金属添加浓度与子实体含量的回归分析发现二者的线性相关关系显著。按照国家标准中As、Hg、Pb、Cd的最高允许含量确定真姬菇的培养料中As、Hg、Pb、Cd的安全限量值应不高于5．0、1．0、3．5、1．0mg／kg。     

溴氰菊酯对4种海水养殖生物的毒性及其积累

以海水养殖的2种甲壳类动物(远海梭子蟹Portunus pelagicus、日本囊对虾Marsupenaeus japonicus)和2种双壳类动物(文蛤Meretrix meretrix、菲律宾蛤仔Ruditapes philippinarum)为材料,进行了溴氰菊酯对4种海水养殖生物的急性毒性及其积累实验研究。结果显示,4种海水养殖生物的死亡率与溴氰菊酯浓度及其暴露时间成显著正相关。溴氰菊酯对远海梭子蟹和日本囊对虾的24 h LC50、48 h LC50、96 h LC50分别为2.07×10–4、1.70×10–4、1.10×10–4 mg/L和7.32×10–4、3.90×10–4、1.43×10–4 mg/L,安全浓度分别为3.44×10–5 mg/L和3.32×10–5 mg/L;溴氰菊酯对文蛤和菲律宾蛤仔的24 h LC50、48 h LC50、96 h LC50分别为1.52、0.30、0.27 mg/L和0.67、0.11、0.06 mg/L,安全浓度分别为3.51×10–3 mg/L和9.50×10–4 mg/L。溴氰菊酯对远海梭子蟹、日本囊对虾的毒性明显大于文蛤和菲律宾蛤仔。文蛤和菲律宾蛤仔在溴氰菊酯平均浓度分别为0.86–0.05 mg/L和0.37– 0.03 mg/L的水体中暴露24–96 h时,其对溴氰菊酯的积累系数分别为2.57–12.40和3.03–27.85,文蛤和菲律宾蛤对溴氰菊酯的积累率与暴露时间成正相关,与暴露浓度成负相关。不同种类的海水养殖生物对溴氰菊酯的敏感性及其积累率存在显著差异。     

Accumulation of zinc and its effects on the growth, reproduction and life cycle of Drawida willsi (Oligochaeta), a dominant earthworm in Indian crop fields

 Accumulation of Zn and its effects on the growth, reproduction and life cycle of the earthworm Drawida willsi were determined. D. willsi did not reveal any significant changes in their mass at any of the concentrations of Zn (50, 200 and 400 mg kg^–1) compared to in untreated soils. The Zn concentrations in the exposed earthworms were significantly increased, but they were able to regulate their body content of Zn within a range of 116–125 mg kg^–1 (dry wt) in 200–400 mg kg^–1 Zn-treated soil. Reproduction was significantly reduced when the Zn concentration in soil exceeded 200 mg kg^–1. The drop in reproduction at elevated concentrations of Zn apparently resulted in a delay in completion of the life cycle and a decline in the total population. Received: 9 September 1998     

Bioaccumulation of hexachlorocyclohexane,dichlorodiphenyltrichloroethane, and estradiol-17β in catfish and carp during the pre-monsoon season in India

This investigation was performed to monitor hexachlorocyclohexane isomers (HCHs), dichlorodiphenyltrichloroethane (DDT, and its metabolites, refered to as DDTs), plasma levels of estradiol-17β (E2), and the gonadosomatic index (GSI) between sampling sites of unpolluted ponds of Gujartal, Jaunpur (control site) and the polluted rivers Gomti (Jaunpur) and Ganga (Varanasi), which affect the reproductive physiology of some edible catfish and carp during the pre-monsoon season. HCHs and DDTs were measured by gas liquid chromatography (GLC) and hormones by radioimmunoassay (RIA). The results indicated that the level of HCHs and DDTs was very high in both the catfish and the carp captured from the polluted rivers compared with the fish captured from the control site. The GSI and E2 values were lower in both groups of fish when compared to the fish from the control site. The results also indicate that catfish showed greater bioaccumulation of HCHs and DDTs than carp, above the permissible limit, as compared to the fish from the control site. In conclusion, fish from the Gomti and Ganga rivers were highly polluted when compared with fish from the control site, as was evident from high levels of tissue bioaccumulation of HCHs and DDTs and decreased levels of plasma E2, inhibiting the reproductive physiology of these species at the receptor level. The levels exceeded the maximum residue limits (MRL) as recommended by Codex, hence it is suggested that the fish should be avoided for food purposes.     

内蒙古羊草草原均腐土营养元素的生物积累

本文研究了内蒙古锡林河流域暗厚简育干润均腐土(J_2、4、5)氮、磷、钾、硫、铁等不同营养元素的生物积累。结果表明:植物地上部生物积累的特点为:氮累积累量高达3.43克·米^-2,钾素为2.916克·米^-2。不同植物在生物积累中的作用,除受元素含量高低的影响外,还取决于该植物的生物量。生长在暗厚简育干润均腐土上的羊草,由于生物量高,所以在生物积累中所占例亦最高,一般都高于50%。植物地下部的生物积累亦属氮素最高,可达16.53克·米^-2。地下部生物量沿剖面分布为上大下小呈“丁”字型,其营养元素的生物积累在上部土层高于下部土层。土壤对五种营养元素生物积累的顺序为:N>K>S>Fe>P。在地上部和地下部的分配中除钾素外,其余四种元素在地下部的生物积累都占绝大部分,这一特点的存在,为保持土壤肥力和草原的持续利用起着重要作用。为维持草原生态系统营养元素的平衡,应对放牧地、割草地补充相应数量的氮、磷、钾等营养元素。