红壤中La的生物富集及其对玉米幼苗生长影响研究

Through a pot culture lanthanum nitrate was applied to maize seedlings grown in a red loamy soil to investigate the physiological and toxic effects of added La on the growth of crop seedlings and La bioaccumulation to help understand the environmental chemistry behaviors of rare earth element as fertilizers in soils. Compared to the control, La concentrations in shoots and especially in roots of maize seedlings increased with an increase of La in the soil. Also, with added concentrations of La 〉 0.75 g La kg-1 soil and ≥ 0.05 g La kg^-1 soil, the dry weight of shoots and roots of maize seedlings was significantly reduced （P ≤ 0.05）, respectively, compared with the control. Additionally, La ≥0.5 g kg^-1 in the soil significantly inhibited （P ≤ 0.05） primary root elongation. Roots were more sensitive to La stress than shoots and thus could be used as a biomarker to La stress. Overall, in the red loamy soil studied, La had no significant beneficial effects on the growth of maize at the added La levels above 0.1 g kg^-1 soil.     

水葱对五氯酚污染土壤植物修复的初步研究

采用水池栽培水葱(ScirpustabernaemontaniGmel),研究了该植物对土壤中五氯酚(PCP)的生物富集能力。结果表明,供试污染土壤中五氯酚的起始浓度为2000.00μg.kg-1,经30、60、90、120d后种植水葱培养池土壤中五氯酚的含量分别为起始浓度的28.34%、1.03%、0.86%和0.088%;而对照未种植水葱的培养池土壤中五氯酚的含量分别为起始浓度的95.09%、81.17%、71.32%和63.75%;水葱根部五氯酚的含量由起始的579.55μg.kg-1,30d后达到最高富集量即2090.00μg.kg-1,由此证实水葱对五氯酚具有一定的富集能力。因此,利用水葱修复土壤中难降解有机污染物五氯酚是一项可行的技术。     

Microplastics in soil: Impacts and microbial diversity and degradation

Microplastics(MPs) are plastic particles less than 5 mm in size that have become a major environmental pollutant due to their ubiquitous and persistent nature. Microplastic contamination of the aquatic environment has received the most attention so far, whereas the current understanding of MP prevalence and its impacts in the terrestrial environment is largely limited. The MP contamination of soil can cause bioaccumulation and toxicity in terrestrial animals and plants, which can consequently affect human health. This review is aimed towards combining the available information on the occurrence, sources, and effects of MPs on the different aspects of the terrestrial environment and to highlight the limitations in our knowledge regarding the nature and impacts of MPs in soil. The review also highlights microbial degradation of MPs as an advancing research area, with numerous microorganisms being identified as capable of efficiently degrading this persistent contaminant.     

蔬菜对多氯代有机污染物富集转移特征初探

采用野外调查采样和室内培养、分析相结合的方法,探讨蔬菜对多氯代有机污染物（PCOPs）的富集和转移特征。结果表明：不同旱地蔬菜对不同PCOPs的富集能力和转移能力各不相同,主要体现在叶菜类对六六六（HCB）的富集系数最高,根菜类对滴滴涕（DDT）类的转移系数最高等特点;不同盆栽蔬菜的富集和转移特点和旱地蔬菜的基本一致,且随着土壤受污染程度的加剧会导致其富集系数和转移系数降低,这与蔬菜生物量较小而影响其对PCOPs的富集和转移能力有关。研究结论可为了解PCOPs由土壤环境进入蔬菜体内及其在体内的转移提供科学依据。     

Use of tissue and sediment‐based threshold concentrations of polychlorinated biphenyls (PCBs) to protect juvenile salmonids listed under the US Endangered Species Act

• 1. Under the Endangered Species Act, the National Marine Fisheries Service has authority to protect listed species from any adverse actions that may jeopardize the population's ability to recover and increase to sustainable levels. Listed salmon species in the northwest United States are known to travel through urban areas in their migration from river to ocean. Species such as the chinook salmon (Oncorhynchus tshawytscha) often spend several weeks in these urban estuaries where they can be highly exposed to urban‐related contaminants that reside in the sediments and accumulate in their prey species. The concern is that these contaminants are bioaccumulated to levels that may impact the ability of individual salmon to grow and mature normally. This paper provides a framework for determining the tissue and sediment concentrations of polychlorinated biphenyls (PCBs) that are likely protective against adverse effects in listed salmonid species.
• 2. The relevant ecotoxicological literature was examined and 15 studies were selected that met the pre‐established criteria outlined here. For each study, the lowest tissue concentration (residue) of total PCBs associated with a biological response was selected. The tissue concentration associated with the 10th percentile of these 15 studies was chosen to represent the residue effect threshold (RET) above which wild juvenile salmonids would be expected to exhibit adverse sublethal effects from accumulated PCBs. This value (2.4 μg PCBs g^?1 lipid) is expressed in terms of the lipid‐normalized concentration because of the large effect lipid can have on the expressed toxicity and the substantial variability in lipid content observed in salmonids over their life cycle.
• 3. A sediment concentration that is expected to produce the RET was then determined using the biota‐sediment accumulation factor approach. The sediment effect threshold, which varies with the total organic carbon content in sediment, is the level above which adverse effects may be expected in juvenile salmonids due to accumulation of PCBs from environmental exposure. Bioaccumulation of PCBs was examined in one river system as a model for determining an appropriate bioaccumulation factor for wild juvenile chinook salmon.
• 4. Evaluation of exposure to potentially deleterious concentrations of PCBs based on tissue residues is the preferred approach; however, the sediment effect threshold may also be used in cases where bioaccumulation has been characterized in an estuary. The threshold values presented here are intended as interim guidelines that should be modified as more data become available. Additionally, because of the uncertainty around many of the factors and assumptions that comprise the single threshold effect values, it is recommended that future studies be employed to help determine a range of acceptable values that would afford protection under various environmental and biological conditions.

Published in 2002 by John Wiley & Sons, Ltd.     

不同污染背景生境中背角无齿蚌的重金属积累特征

以中国水产科学研究院淡水渔业研究中心南泉基地(无明显外源污染)、太湖梅梁湾(历史上污染较为严重)以及云南茈碧湖(高原洁净湖泊)生境中的背角无齿蚌(Anodonta woodiana)为对象,应用电感耦合等离子质谱仪(ICP-MS)分析了蚌样软组织中15种重金属(Al、Cr、Mn、Fe、Co、Ni、Cu、Zn、As、Mo、Ag、Cd、Ba、Tl和Pb)的积累特征.结果表明:南泉基地养殖蚌中Al、Cr、Mn、Fe、Ni、Cu、Zn、As、Cd和Ba的含量显著低于梅梁湾野生蚌(P＜0.05),茈碧湖野生蚌中Al、Mn、Ni、Cu、Zn、As、Cd、Ba和Pb的含量显著低于梅梁湾蚌样(P＜0.05),但前者Mo和Tl的含量显著高于后者(P＜0.05);南泉基地蚌样中Cr、Fe、Mo和Tl的含量显著低于茈碧湖蚌样(P＜0.05),而Cu、As和Pb的含量显著高于后者(P＜0.05).梅梁湾、南泉基地和茈碧湖蚌的金属污染指数(MPI)分别为11.1、1.8和1.0,显示出南泉基地养殖蚌重金属总体污染水平很低,与生活于洁净水体茈碧湖中蚌的情况相近,而远低于采自太湖梅梁湾蚌的水平.     

花生不同品种植株重金属As和Hg的富集与转运规律

在大田生产条件下,以8个主栽花生品种为试材对花生植株不同器官中重金属As和Hg元素的吸收、富集与转运规律进行了研究。结果表明,供试的花生品种植株根系、茎叶中As和Hg含量存在显著性差异,籽仁中As含量和果壳中Hg含量存在显著性差异,而果壳中As和籽仁中Hg含量差异不显著。花生植株根系As含量最高,其次为茎叶和果壳,籽仁中的含量最低;花生植株根系Hg含量最高,其次为果壳和茎叶,籽仁中的含量最低。不同花生品种植株根系、茎叶、籽仁和果壳中As和Hg的富集量均存在显著性差异,植株中的As和Hg主要富集于茎叶中,其次为果壳,根系和籽仁中富集量较低。不同花生品种茎叶和籽仁中的As转运量系数差异显著,果壳中的差异不显著;花生根系吸收的As转运到茎叶中最多,其次为果壳中,转运到籽仁中最少。不同花生品种茎叶、籽仁和果壳中的Hg转运量系数均呈现显著性差异,花生根系吸收的Hg主要转运到植株茎叶中,籽仁和果壳中很少。花生对As和Hg的富集量和转运能力差异是造成花生籽仁含量高低的主要原因。     

Total Mercury Bioaccumulation in Tissues of Carnivorous Fish (Micropogonias furnieri and Cynoscion acoupa) and Oysters (Crassostrea brasiliana) from Sepetiba Bay,Brazil

Total mercury (Hg) levels were determined by cold vapor atomic absorption spectrophotometry (CVAAS) in tissues of two species of carnivorous fishes and in the soft tissue of oysters caught in Sepetiba Bay, Brazil. Hg was distributed unevenly in the organs and tissues of the fish; the mean Hg content was highest in the kidneys (0.048 μg/g wet weight) and lowest in the gills (0.004 μg/g w.w.). Mean Hg levels were higher in the oysters (0.052 μg/g w.w.) than in the fish (0.022 μg/g w.w). The total Hg concentration did not exceed the maximum concentration for food allowed by Brazilian legislation in any of the fish and oyster samples analyzed. Moreover, the Hg concentrations observed were all within the maximum level for fish recommended by the Food and Agriculture Organization (FAO; 0.5 μg/g w.w.).     

水体中铅对长江上游6种鱼类的急性中毒效应

为了检验不同鱼类对水体中铅(Pb)的耐受能力的差异,在控制实验室水体的温度(27.5±0.2)℃、硬度(10.0±0.5)Ca CO3mg/L、p H值(7.0±0.1)等条件下,测定了草鱼(Ctenopharyngodon idellus)(22.13±0.31)g、鲫(Carassius auratus)(25.36±0.36)g、南方鲇(Silurus meridionalis)(21.28±0.20)g、团头鲂(Megalobrama amblycephala)(21.39±0.20)g、胭脂鱼(Myxocyprinus asiaticus)(22.34±0.32)g和中华倒刺鲃(Spinibarbus sinensis)(21.36±0.21)g这6种鱼经水体Pb 96 h急性暴露后的半致死浓度(96 h LC50),以及Pb在鱼体内的累积量。结果发现,水体中的Pb对草鱼、鲫、南方鲇、团头鲂、胭脂鱼和中华倒刺鲃的96 h LC50值分别为3.73、11.59、6.59、3.27、0.33和3.00 mg/L;6种鱼对Pb的耐受能力依次为:鲫南方鲇草鱼团头鲂中华倒刺鲃胭脂鱼。同种鱼中Pb暴露致死鱼体和未死亡鱼体内的Pb累积量均分别随着暴露的浓度的升高而增加;在相同Pb浓度处理条件下,同种鱼中死亡鱼体的Pb累积量高于未死亡鱼体。水体硬度和鱼体重会影响重金属Pb对鱼类的96 h LC50。较高硬度水体暴露的Pb对鱼体的毒性较小,同种鱼体重较大的个体对重金属Pb的耐受能力较强。同种鱼不同时间段死亡鱼体中的Pb累积量没有显著性差异;每种实验鱼因Pb暴露致死群体的平均Pb累积量均分别高于其未死亡鱼群体,除南方鲇外,其余5种鱼二者间的差异达到了显著性水平。     

Growth and enzymatic activity of maize (Zea mays L.) plant: Solution culture test for copper dioxide nano particles

Copper (Cu) is an essential micronutrient for plants, which acts either as the metal component of enzymes or as a functional structural or a regulatory co-factor of a large number of enzymes. To understand the possible benefits of applying nanotechnology to agriculture, the first step should be to analyze penetration and transport of nano-particles in plants. The present study was conducted to test the hypothesis that copper nanoparticle would enter into the plant cell and govern the growth of maize plant.A solution culture experiment was conducted to investigate the effect of Cu nano-particles (<50nm) on the growth and enzymatic activity of maize (Zea mays L.) plant. Bioaccumulation of Cu nano-particles in plant was also investigated. Results showed that Cu nano-particles can enter into the plant cell through roots and leaves. Bioaccumulation increased with increasing concentration of Cu nano-particles (NPs), and agglomeration of particles was observed in the cells using transmission-electron microscopy. Application of Cu nano-particles through solution culture as well as spray enhanced the growth (51%) of maize plant in comparison to control. The different enzymatic activities like glucose-6-phosphate dehydrogenase, succinate dehydrogenase, superoxide dismutase, catalase, andguaiacol peroxidase were studied to find a possible pathway through which NPs may affect the enzymatic activity of plant. Amongst the enzymes, the activity of glucose-6-phosphate dehydrogenase was highly influenced by copper oxide (CuO)nano-particles application by spray as well as in solution. Experimental results revealed that CuOnano-particles affected the pentose phosphate pathway of maize plant. The obtained experimental results provided conclusive evidence to indicate that the nano-particles considered under this study could enter into the plant cell, easily be assimilated by plants and also enhanced its growth by regulating the different enzyme activities.