Metal Accumulation in Crayfish,Procambarus clarkii,Exposed to a Petroleum-Contaminated Bayou in Louisiana

Red swamp crayfish (Procambarus clarkii) were placed for a period of 7 days in Bayou Trepagnier, a Louisiana waterway which received petroleum-laden effluents from a manufacturing complex several decades ago. However, coolant water from the plant continued to be released into the bayou until 1995. Analyses of sediments at the exposure site revealed heavy contamination by lead, chromium, and copper, while concentrations of arsenic and cadmium were very low. Significant bioaccumulation of lead was observed in the hepatopancreas and gills of 7-day-exposed crayfish, whereas chromium accumulated the most in the gills and blood. Concentrations of copper in the crayfish did not change during the course of the study, suggesting that this essential metal constituent of the respiratory pigment is successfully regulated even when crayfish are exposed to relatively high levels of copper in the sediments. There was no metal accumulation in the abdominal muscle of the crayfish. That damage to the hepatopancreas occurred during the exposure is suggested by histopathological studies which revealed swollen and vacuolated R cells and an increase in the pH of the digestive juices. Blood glucose levels, as well as ovarian and hepatopancreatic indices, were unchanged. This study demonstrates that accumulation of nonessential metals in crayfish tissues in a wetland environment contaminated by mixed pollution (metals and hydrocarbons) reflects the concentrations of metals in the sediment.     

Response and Recovery of Brain Acetylcholinesterase Activity in the European Eel,Anguilla anguilla,Exposed to Fenitrothion

European eel (Anguilla anguilla) were exposed to sublethal fenitrothion concentrations in a continuous flow-through system for 4 days. Brain acetylcholinesterase (AChE) activity was evaluated after 2, 8, 12, 24, 32, 48, 56, 72, and 96 h pesticide exposure. Results indicated that AChE activity in eel brains decreased as the concentration of fenitrothion increased. The pesticide induced significant inhibitory effects on the AChE activity ofA. anguilla,ranging from >40% inhibition at a sublethal concentration of 0.02 ppm to >60% inhibition at a sublethal concentration of 0.04 ppm. Eel were exposed to both fenitrothion concentrations for 96 h and then allowed a period of recovery in pesticide-free water. Samples were removed at 8, 12, 24, 48, 72, 96, 144, and 192 h and eel brain AChE activity was evaluated. Following 1 week of recovery, the AChE activity of those animals previously exposed to 0.02 and 0.04 ppm fenitrothion was still different from that of the controls. So, the AChE activity of eel brains at the end of the recovery phase remained significantly depressed.     

Toxicity and Bioaccumulation of Cadmium in Marine Protozoa Communities

The behavior of cadmium in a protozoan community was analyzed in order to obtain new data concerning the toxicity and bioaccumulation of this heavy metal. For this purpose, microcosms with different concentrations of the pollutant (without cadmium, 500 microg Cd.l-1 and 1000 microg Cd.l-1) were used. Protozoans bioaccumulated 8. 74-283 microg Cd.g-1 dry weight, representing an accumulation capacity of 15.53-69.59 times more than that of bacteria. The addition of cadmium caused a significant reduction in protozoan density, whereas bacterial abundance was not affected.     

Copper and Manganese Influence the Uptake of Cadmium in Marine Macroalgae

Bulletin of Environmental Contamination and Toxicology - Of the numerous published experimental studies in aquatic ecotoxicology, by far the greatest number have been concerned with analysing the...     

Effect of Pollution History on Immunological Responses and Organ Histology in the Marine Mussel Mytilus edulis Exposed to Cadmium

The effect of previous toxicant exposure (i.e., exposure history) on an organism’s response to re-exposure to the toxicant is of considerable interest. The marine mussel Mytilus edulis was collected from reference and polluted sites in southwest England, and groups of mussels from each site were exposed to 20 μg/L CdCl₂ for 0, 1, 4, and 8 days and compared with unexposed controls. End points evaluated were tissue metal and electrolyte concentrations, haemolymph chemistry, haemocyte characteristics [counts, neutral red uptake (NRU), and phagocytosis], histology, and expression of metallothionein gene (mt10) expression in digestive glands. Field-collected animals differed by collection site for some end points at time zero, at which time tissue Fe and Pb concentrations were greater and NRU and condition index lower in mussels from the polluted site. Subsequent exposure to cadmium (Cd) in the laboratory caused Cd accumulation mainly in digestive gland, but there were no site-specific effects on tissue trace-metal concentrations. NRU, phagocytosis, and haemolymph Na⁺ and K⁺ concentrations differed among sites and Cd treatment, but there were no clear trends. Exposure to Cd resulted in lower Ca²⁺ concentrations in gill, digestive gland, and haemolymph in animals from the polluted site compared with controls (Kruskal–Wallis, p ≤ 0.05). Lesions, including necrosis, inflammation, and neoplasia, were observed in animals from the polluted site, but the frequency of these lesions appeared to decrease unexpectedly after Cd exposure. Expression of mt10 increased 3-fold in Cd-exposed animals from the polluted site compared with all other groups (Kruskal–Wallis, p = 0.01). We conclude that Cd exposure affected some immune responses in M. edulis, but pre-exposure history influenced toxicological outcomes of Cd exposure in the laboratory.     

Precision of Dialysis (Peeper) Sampling of Cadmium in Marine Sediment Interstitial Water

Isolating and analyzing interstitial water (IW) during sediment toxicity tests enables researchers to relate concentrations of contaminants to responses of organisms, particularly when IW is a primary route of exposure to bioavailable contaminants by benthic dwelling organisms. We evaluate here the precision of sampling IW with the dialysis or peeper method using sediments spiked with five different concentrations of cadmium. This method is one of several that are commonly used for collecting IW. Seven consecutive ten-day toxicity tests were conducted on these sediments and IW samples were collected at the end of each of these tests. Prior to each test initiation and insertion of IW samplers, sediments were allowed to equilibrate for seven days under flow-through conditions with filtered seawater. At the end of each ten-day testing period, peepers were retrieved, and IW cadmium measured. Data sets were organized by treatment and test number. Coefficients of variation (CV) for the six replicates for each sediment and testing period and for each sediment across testing periods (42 replicates) was used as a measure of sampling precision. CVs ranged from 25 to 206% when individual testing periods were considered, but ranged from 39 to 104% when concentrations for all testing periods were combined. However, after removal of outliers using Dixons Criteria, the CVs improved and ranged from 6 to 88%. These levels of variability are comparable to those reported by others. The variability shown is partially explained by artifacts associated with the dialysis procedure, primarily sample contamination. Further experiments were conducted that support our hypothesis that contamination of the peeper causes much of the variability observed. If method artifacts, especially contamination, are avoided the dialysis procedure can be a more effective means for sampling IW metal.     

山慈菇抑制镉诱发遗传损伤研究

采用活体小鼠骨髓嗜多染红细胞（ＰＣＥ）微核试验（ＭＮＴ）,观察中草药山慈菇（ＢｕｌｂｕｓＩｐｈｉｇｅｎｉａｅ）水溶性提取物的诱变作用及对镉（Ｃｄ）、环磷酰胺（ｃｐ）的抗诱变作用。结果表明：山慈菇可以诱发微核（ＭＮ）产生,但其诱变作用不强;山慈菇对Ｃｄ及ｃｐ的诱变作用具有明显的抑制效果,并对Ｃｄ的抑制作用明显强于对ｃｐ的抑制作用。     

锌或铜诱导肝脏金属硫蛋白结合锌镉比值与铜镉比值的研究

[目的]观察镉（Cd）染毒后锌（Zn）或铜（Cu）诱导肝脏金属硫蛋白（MT）结合锌镉比值（Zn／Cd）与铜镉比值（Cu／Cd）的关系及其意义。[方法]将28只雄性Wistar大鼠随机分为7组,每组4只,分别为：空白对照组（0）,不做任何处理;非预处理组（A1、A2）,皮下注射生理盐水;Zn处理组（B1、B2）,皮下注射ZnCl2（每千克体重染Zn 25mg）;Cu处理组（C1、C2）,皮下注射CuSO4（每千克体重染Cu 12.5mg）。预处理24h后,为实验组动物皮下注射镉．金属硫蛋白（CdMT,Cdmetallothionein）,造成Cd急性中毒,其中A1、B1、C1组每千克体重染Cd0．1mg,A2、B2、C2组每千克体重染Cd0．4mg。24h后处死,取肝脏,制备匀浆。离心后取上清液,加入SephadexG-75色谱层析柱。[结果]空白对照组动物肝脏中与MT结合的最主要金属元素是Zn,而Cd、Cu含量在检测限以下;与前者相比,A1、A2组动物肝脏MT和Cd含量随染毒剂量增加而升高,且A1、A2组肝脏MT中Zn／Cd值分别为20．0和10．0;B1、B2组肝脏MT中Zn／Cd值分别为20．8和20．3,Cu离子未检出;C1、C2组肝脏MT的Cu／Cd值分别为80．0和36．5,Zn含量下降明显。[结论]不同剂量Cd染毒后,Zn或Cu诱导动物肝脏MT中金属含量比例存在差异,Cu／Cd值高于Zn／Cd值,即与MT结合的Cd相比,Cu更易取代与MT结合的Zn。另外,肝脏中非MT结合Zn也是影响与MT结合的金属离子稳态的重要因素。     

Cadmium bioaccumulation in Proisotoma minuta in relation to bioavailability in soils

Proisotoma minuta are widely distributed in Australian soils, especially in rehabilitated mine sites and in cotton fields. Laboratory studies were conducted to evaluate the accumulation of cadmium (Cd) in the Collembolan, P. minuta, using four Australian soils. Cadmium accumulation in body tissues was measured by atomic absorption spectroscopy of acid digests of the Collembola. Cadmium soil bioavailability of four Australian soils was determined using a sequential extraction method. The highest soluble-exchangeable Cd concentration was observed in Box Hill soil with the lowest pH, organic carbon, CEC, clay and very low iron content. Robertson soil with high pH, CEC, organic carbon, clay and iron content had the highest Cd organic- and oxide-bound concentrations. This may explain why there was higher Cd accumulation in P. minuta in the Box Hill soil than in the Robertson soil. The Cd uptake of P. minuta was predominantly correlated with soluble-exchangeable Cd concentration in soils followed by organic- and oxide-bound Cd concentrations. Presumably, soluble-exchangeable Cd is more readily available for P. minuta uptake than other Cd fractions.     

大连市售海产品铅、镉污染状况分析与评价

目的 了解大连市售常见海产品铅、镉污染状况并进行评价. 方法 对大连市售海鱼、贝类、甲壳类中铅、镉含量进行测定,采用重金属单因子污染指数法进行污染状况评价. 结果 海鱼铅平均含量为0.249 mg/kg,超标率18.9％.贝类铅平均含量为0.262 mg/kg,超标率2.6％.甲壳类镉的平均含量为0.223 mg/kg,超标率为18.8％. 结论 大连市售部分海产品存在不同程度的铅、镉污染.海鱼和贝类存在铅的轻度污染,甲壳类存在镉的中度污染.     

镉在肝细胞内的吸收过程及其对肝细胞内钙稳态的影响

采用游离原代肝细胞培养技术，观察镉（Ｃｄ）在肝细胞内的吸收过程及其对肝细胞内钙稳态的影响。实验发现，肝细胞对Ｃｄ的吸收分为２个时期，首先是一个迅速吸收期，随后有一个缓慢吸收期；实验还发现，在Ｃｄ作用浓度为３．５６μｍｏｌ／Ｌ时，肝细胞内钙稳态并未发生明显变化；与此同时，肝细胞内ＣａＭ活性和Ｃａ（２＋）－Ｍｇ（２＋）－ＡＴＰ酶活性持续升高；结果揭示，Ｃｄ可能通过激活ＣａＭ，导致Ｃａ（２＋）－Ｍｇ（２＋）－ＡＴＰ酶活性升高，增强了生物膜的钙隔离作用，造成了细胞内游离钙离子浓度不变。     

大连市售海产品铅、镉污染状况分析与评价

目的 了解大连市售常见海产品铅、镉污染状况并进行评价. 方法 对大连市售海鱼、贝类、甲壳类中铅、镉含量进行测定,采用重金属单因子污染指数法进行污染状况评价. 结果 海鱼铅平均含量为0.249 mg/kg,超标率18.9％.贝类铅平均含量为0.262 mg/kg,超标率2.6％.甲壳类镉的平均含量为0.223 mg/kg,超标率为18.8％. 结论 大连市售部分海产品存在不同程度的铅、镉污染.海鱼和贝类存在铅的轻度污染,甲壳类存在镉的中度污染.     

某镉电池厂镉作业女性32人尿镉及血清中性激素的水平

目的了解镉作业女工尿镉及血清中性激素水平改变的影响因素并初步探讨其机制。方法 2010年11月,选取某镉电池工厂镉作业女工100名作为接触组,按工作场所空气中镉含量的水平分成高、低2个接触浓度组;并选取来自同一家工厂未接触镉作业的50名女工作为对照组,测定3组人群的尿镉、促卵泡刺激素（FSH）、促黄体生成素（LH）及雌二醇（E2）的水平并进行统计分析。结果 2个接触组尿镉含量和异常率均明显高于对照组,差异有统计学意义（P〈0.05,P〈0.01）;高浓度接触组工人在月经周期中的月经期血清中FSH水平和E2水平均低于对照组,差异均有统计学意义（P〈0.01）;增殖期血清中LH水平低于对照组,差异有统计学意义（P〈0.01）;分泌期血清中LH和E2水平均低于对照组,差异均有统计学意义（P〈0.01）。结论在该研究的条件下,工作场所中氧化镉浓度超标是导致尿镉水平升高的主要危险因素;镉暴露可能对下丘脑-垂体-卵巢轴的性激素分泌功能造成影响,从而对女性工人的生殖系统产生内分泌干扰作用。     

慢性有机磷农药接触对羧基酯酶活力的影响

目的　酯酶不仅在有机磷农药解毒中发挥重要作用 ,而且与心血管疾病有密切关系。我们研究3种酯酶 (丁酰胆碱酯酶BchE、羧酸酯酶CarbE和对氧磷酶PonE)的酶活力在一般人群中的特点 ,探讨有机磷农药慢性接触对酶活力的影响 ,为其他研究提供基线资料。方法　选取 10 0名无有机磷农药接触的对照人群和 75名长期接触有机磷农药的生产工人 ,检测外周血酯酶活力 ,描述正常成人酶活力的特点 ,分析有机磷接触对酯酶活力的影响。结果　对照人群BchE均值为 (78 3± 30 4 )mmol/(ml·h) ;CarbE均值为(36 2 7± 195 0 )nmol/(ml·min) ;PonE均值为 (332 6± 96 2 )nmol/(ml·min)。 3种酶活力在人群中均呈正态分布。有机磷农药接触工人BchE活力为 (2 7 3± 2 1 7)mmol/(ml·h) ;CarbE活力为 (2 35 6± 10 4 0 )nmol/(ml·min) ;PonE活力为 (30 7 8± 10 7 0 )nmol/(ml·min)。结论　 3种酯酶活力无年龄和性别差异。有机磷接触工人的BchE和CarbE活力与对照人群比较 ,差异有显著性 ,说明有机磷能抑制BchE和CarbE活力 ,而对对氧磷酶活力无抑制作用。提示 ,BchE和CarbE活力可以作为反映有机磷农药接触     

大鼠体内镉负荷与尿金属硫蛋白关系的实验研究

[目的]分析大鼠尿金属硫蛋白(UMT)与体内镉负荷的关系,探讨UMT作为镉接触性生物标志物的可行性。[方法]24只SD大鼠分为4组,分别皮下注射给予0、0.5、1.0、2.0mgCd/kg体重CdCl27d。原子吸收分光光度法(AAS)测定肝脏、肾脏、胰脏、尿液、血液中镉的含量;比色法测定尿N-乙酰-β-D-氨基葡萄糖苷酶(UNAG)水平;酶联免疫吸附法(ELISA)检测UMT的含量。[结果]镉染毒大鼠血镉、尿镉、肝镉、肾镉、胰镉含量随染镉剂量的增加而明显增加,与对照组相比差异有统计学意义(P<0.05);各染镉组大鼠UNAG水平未见明显改变(P>0.05);UMT含量随着染镉剂量的增加而明显增加(P<0.05),并且与肝镉、肾镉、胰镉、血镉、尿镉含量呈明显正相关,相关系数分别为0.703、0.815、0.691、0.654、0.641(P<0.01)。[结论]UMT与体内镉负荷指标间存在较好的一致性,能反映机体镉负荷水平,可作为镉接触生物标志物。