铜离子诱发(歺又鱼)鲦鱼红细胞微核及核异常的研究

目的 通过(歺又鱼)鲦鱼红细胞研究铜离子的遗传毒性,寻找对诱变物敏感的鱼类.方法 选择120尾(歺又鱼)鲦鱼,随机分为8组,每组15尾,分别用Cu2 浓度为0.01、0.02、0.04、0.08、0.16、0.32、0.64、1.28 mg/L的CuSO4溶液染毒,染毒在同一规格的塑料箱内进行.对照组以纯净水饲养.每一浓度组在6、12、24、48 h时随机取鱼3尾(0.64mg/L组每次处理2尾),用纱布将鱼体表水分擦干.断尾取血,涂片,观察不同浓度、不同染毒时间铜离子对(歺又鱼)鲦鱼红细胞微核及核异常的影响.结果各 染毒组(歺又鱼)鲦鱼红细胞微核率及核异常率均低于对照组,差异有统计学意义(P＜0.05或P＜0.01).在12、24h时,在一定浓度(0.01～0.16 mg/L)范围内(歺又鱼)鲦鱼红细胞微核率与铜离子浓度成正相关,但当浓度过高(0.32、0.64 mg/L)时,微核率反而降低.当铜离子浓度较低(0.01～0.08 mg/L)时,微核率随染毒时间的延长而升高.结论 (歺又鱼)鲦鱼对诱变物敏感,可以作为微核实验的良好材料来检测诱变物的遗传毒性.     

铜离子诱发(歺又鱼)鲦鱼红细胞微核及核异常的研究

目的 通过[can]鲦鱼红细胞研究铜离子的遗传毒性，寻找对诱变物敏感的鱼类。方法 选择120尾[can]鲦鱼，随机分为8组，每组15尾，分别用Cu^2浓度为0．01、0．02、0．04、0．08、0．16、0．32、0．64、1．28mg／L的CuSO4溶液染毒，染毒在同一规格的塑料箱内进行。对照组以纯净水饲养。每一浓度组在6、12、24、48h时随机取鱼3尾（0．64mg／L组每次处理2尾），用纱布将鱼体表水分擦干。断尾取血，涂片，观察不同浓度、不同染毒时间铜离子对[can]鲦鱼红细胞微核及核异常的影响。结果 各染毒组[can]鲦鱼红细胞微核率及核异常率均低于对照组，差异有统计学意义（P＜0．05或P〈0．01）。在12、24h时，在一定浓度（0．01～0．16mg／L）范围内[can]鲦鱼红细胞微核率与铜离子浓度成正相关，但当浓度过高（0．32、0．64mg／L）时，微核率反而降低。当铜离子浓度较低（0．01～0．08mg／L）时，微核率随染毒时间的延长而升高。结论 [can]鲦鱼对诱变物敏感，可以作为微核实验的良好材料来检测诱变物的遗传毒性。     

氯化镍染毒对小鼠外周血网织红细胞微核形成的影响

目的研究氯化镍(NiCl2)诱导小鼠外周血网织红细胞微核形成的作用.方法将30只健康的成年雄性NIH小鼠随机分为6组,设生理盐水对照组、秋水仙素阳性对照组(剂量为0.75 mg/kg)、环磷酰胺阳性对照组(剂量为40.0mg/kg)和NiCl2染毒组(剂量分别为5.0、10.0、20.0 mg/kg),分2次腹腔注射染毒,间隔24 h,每次按0.1 ml/10 g体重腹腔注射.采用转铁蛋白受体荧光抗体和碘化丙碇染色,以疟原虫感染小鼠外周血红细胞为微核生物模型,调校流式细胞仪,检测秋水仙素、环磷酰胺和0、5.0、10.0、20.0 mg/kg NiCl2染毒后小鼠外周血含微核网织红细胞率的变化.结果秋水仙素和环磷酰胺染毒小鼠的外周血含微核网织红细胞率均明显高于对照组小鼠(P＜0.01),但不同剂量NiCl2染毒小鼠外周血含微核网织红细胞率均未见明显升高(P＞0.05).结论该研究条件下未观察到氯化镍有明显的诱导小鼠外周血网织红细胞微核形成的作用.     

香烟烟气与纳米二氧化钛对人支气管上皮细胞的遗传损伤研究

目的探讨香烟烟气与纳米二氧化钛(nano-TiO2)单独及联合染毒对人支气管上皮细胞株(16-HBE)DNA断裂及染色体畸变的影响。方法将状态良好的16-HBE单独及混合暴露于香烟烟气提取物(cigarette smoke extract,CSE)和nano-TiO2,其终浓度分别为0、0mg/L,50、0mg/L,75、0mg/L,100、0mg/L,0、10mg/L,50、10mg/L,75、10mg/L,100、10mg/L。24h后,采用四甲基偶氮唑盐(MTT)法检测HBE的存活率,以单细胞凝胶电泳检测DNA损伤程度,以微核试验检测染色体畸变。结果除10mg/L nano-TiO2单独染毒组以外,各染毒组的存活率较对照组降低,彗星率(Comet%)较对照组升高,有统计学意义(P0.05);75、100mg/L CSE单独染毒组及各联合染毒组的彗星尾长(Ltail)较对照组升高,有统计学意义(P0.05);100mg/L CSE单独染毒组及100mg/L CSE+10mg/L nano-TiO2联合染毒组的尾部DNA含量(TailDNA%)较对照组升高,有统计学意义(P0.05);100mg/L CSE单独染毒组及75mg/L CSE+10mg/L nano-TiO2,100mg/L CSE+10mg/L nano-TiO2联合染毒组的尾矩(TM)、Olive尾矩(OTM)均较对照组升高,有统计学意义(P0.05);除10mg/L nano-TiO2单独染毒组以外,各染毒组微核率均较对照组升高,有统计学意义(P0.01)。各指标析因分析结果均未显示CSE及nano-TiO2联合染毒有交互作用。CSE与HBE的彗星率和微核率均呈正相关(P0.01)。结论香烟烟气诱导的HBE DNA断裂和染色体畸变随染毒剂量增加而加重;尚未见香烟烟气和nano-TiO2对HBE的遗传损伤具有交互作用。     

铅对小鼠骨髓多染红细胞微核率的影响

本项研究用醋酸铅(每次染毒剂量:200mg/kg和50mg/kg两组)、醋酸(0.001mol/L,每次染毒剂量:0.1ml/10g),蒸馏水,环磷酰胺(每次染毒40mg/kg),分别对小鼠作经口染毒,以骨髓多染红细胞微核率为指标,发现铅可致微核率明显增高,其作用与染毒剂量和血铅浓度呈明显的正相关(r_1=0.968,r_2=0.998)。     

低剂量甲基叔丁基醚诱导小鼠骨髓细胞微核率变化的适应性反应

目的研究小鼠接触低剂量甲基叔丁基醚(MTBE)能否诱导其对后续大剂量接触该物质所致遗传物质损伤的适应性反应。方法将35只昆明种雄性小白鼠随机分为7组,空白对照组不做任何处理,其它6组通过静式吸入染毒的方式,用1260、630、315、126、63和0mg/m3的MTBE预处理各组小鼠,每天2h,30天后用10000mg/m3的MTBE进行染毒,取小鼠胸骨骨髓制片,观察骨髓网织红细胞微核率的改变。结果10000mg/m3MTBE染毒小鼠2h后,骨髓网织红细胞微核率与空白对照组相比明显增加(P0.05),表明浓度为10000mg/m3的MTBE吸入染毒2h可以造成小鼠遗传物质的明显损伤。126mg/m3剂量处理小鼠30天后,再接受10000mg/m3MTBE的染毒,其骨髓网织红细胞微核率明显低于单纯高剂量处理组的微核率(P0.05),而与空白对照组比较,差异无显著性(P0.05)。表明小鼠长期接触126mg/m3低剂量的MTBE可诱导其对后续大剂量MTBE染毒的遗传损伤作用产生抵抗力。结论吸入低剂量MTBE可诱导小鼠产生适应性反应。     

铁路危险品货运站空气颗粒污染物有机提取物的小鼠外周血网织红细胞微核试验

目的探讨铁路危险品货运站空气颗粒污染物对小鼠外周血网织红细胞微核的诱导作用.方法选用雄性BALB/c小鼠随机分为实验组和对照组,空气颗粒污染物的丙酮提取物按20、40、80、160 mg/kg的剂量,以腹腔注射方式一次性染毒.同时进行低剂量(10 mg/kg)腹腔注射重复式染毒,每天1次共5天,于染毒后24、48、72 h采集尾血进行网织红细胞微核分析.结果外周血网织红细胞微核率呈现出良好的时间-反应关系,微核的高峰出现在染毒后48 h,此时各剂量组微核率均高于对照组.低剂量重复染毒试验结果表明,在24～72 h内网织红细胞微核率始终处于较高水平,与对照组相比差异有显著性(P＜0.05).结论铁路危险品货运站空气颗粒污染物对雄性小鼠外周血网织红细胞微核具有明显的诱导作用.     

壬基酚对泥鳅的遗传毒性效应

为观察壬基酚对泥鳅的遗传毒性作用,将泥鳅分别为饲养于50、200、500、1000μg/L壬基酚染毒溶液中6、12、24、48h,并设空白对照(曝气脱氯自来水)组和溶剂对照(0.02％乙醇)组.采用微核试验统计微核细胞数及核异常细胞数,并计算微核率和核异常率.结果显示,与溶剂对照组比较,50μg/L壬基酚染毒24、48h以及200、500、1000μg/L壬基酚染毒6～48h泥鳅的红细胞微核率和核异常率均较高,差异有统计学意义(P＜0.05).随着壬基酚染毒浓度的升高以及染毒时间的延长,泥鳅红细胞的微核率和核异常率呈先升高后下降的趋势.提示较高浓度的壬基酚对泥鳅具有遗传毒性.     

铁路危险品货运站空气颗粒污染有机提取物的小鼠外周血网织红细胞微核试验

目的 探讨铁路危险品货运站空气颗粒污染物对小鼠外周血网织红细胞微核的诱导作用。方法 选用雌性BALB／c小鼠随机分为实验组和对照组,空气颗粒污染物的丙酮提取物按20、40、80、160mg/kg的剂量,以腹腔注射方式一次性染毒。同时进行低剂量（10mg/kg）腹腔注射重复式染毒,每天1次共5天,于染毒后24、48、72h采集尾血进行网织红细胞微核分析。结果 外周血网织红细胞微核率呈现出良好的时间－反应关系,微核的高峰出现在染毒后47h,此时各剂量组微核率均高于对照组。低剂量重复染毒试验结果表明,在24－72h内网织红细胞微核率始终处于较高水平,与对照组相比差异有显著性（P＜0．05）。结论 铁路危险品货运站空气颗粒污染物对雌性小鼠外周血网织红细胞微核具有明显的诱导作用。     

亚硝酸钠对泥鳅红细胞的遗传损伤研究

[目的]研究亚硝酸钠在不同浓度和不同染毒时间对泥鳅红细胞的损害,观察改性竹炭-K对亚硝酸钠的吸附效果。[方法]用微核率评价亚硝酸钠对泥鳅的红细胞遗传损伤。[结果]亚硝酸钠的损害主要表现在微核率以及核变形率的增高,且在一定浓度范围内,随着浓度的升高和染毒时间的延长而越来越高。用改性竹炭-K对400mg/L的亚硝酸钠吸附处理,效果显著。[结论]亚硝酸钠对泥鳅的LD50为272mg/L;对泥鳅的遗传损伤表现为微核率和核变形率增高;改性竹炭-K对亚硝酸钠的吸附作用显著。     

Effect of four organochlorine pesticides on the reproduction of freshwater rotifer Brachionus calyciflorus Pallas

Effects of four organochlorine pesticides, including dichlorodiphenyltrichloroethane (DDT), dicofol, endosulfan, and lindane, on the reproduction of freshwater rotifer Brachionus calyciflorus were studied by 3-d population growth tests. Compared to the control, dichlorodiphenyltrichloroethane at 0.64 mg/L, dicofol at 0.8 and 1.2 mg/L, endosulfan at 7.0 mg/L, and lindane at 14.0 mg/L all significantly decreased the population growth rate of the rotifers. Dichlorodiphenyltrichloroethane at concentrations higher than 0.16 mg/L, dicofol at concentrations higher than 0.025 mg/L, endosulfan at concentrations higher than 0.875 mg/L, and lindane at 14.0 mg/L all significantly decreased the mictic rate of the rotifers. Dichlorodiphenyltrichloroethane at 0.24 and 0.32 mg/L increased significantly the fertilization rate, but DDT at 0.64 mg/L inhibited completely the occurrence of fertilized mictic females. Dichlorodiphenyltrichloroethane at 0.32 and 0.64 mg/L, dicofol at 1.2 mg/L, and endosulfan at 7.0 mg/L all significantly decreased the ratio of ovigerous females to nonovigerous females, but the reverse was true for lindane at 7.0 mg/L. Dichlorodiphenyltrichloroethane at 0.0025 and 0.01 mg/L increased significantly the ratio of mictic females to amictic females, but the reverse was true for dicofol at 0.8 mg/L. Both population growth rate and mictic rate of the rotifers were suitable endpoints for assessing the effects of the four organochlorine insecticides on the reproduction of the rotifers, and the latter was more sensitive.     

A tropical sediment toxicity test using the dipteran Chironomus crassiforceps to test metal bioavailability with sediment pH change in tropical acid-sulfate sediments

The wetlands of the Magela floodplain of northern Australia, which is the major sink for dissolved metals transported in the Magela Creek system, contain acid-sulfate sediments. The rewetting of oxidized acid-sulfate soil each wet season produces acidic pulses that have the potential to alter the bioavailability of sediment-associated metal contaminants. Acute toxicity tests (72-h mean lethal concentration [LC50]) using the tropical chironomid Chironomus crassiforceps Kieffer showed that copper toxicity decreased from 0.64 mg/L at pH 6 to 2.30 mg/L at pH 4. Uranium toxicity showed a similar trend (36 mg/L at pH 6 and 58 mg/L at pH 4). Sediment toxicity tests developed using C. crassiforceps also showed that both metals were less toxic at the lower sediment pH with pore-water copper toxicity having a lowest-observed-effect concentration of 4.73 mg/L at pH 4 compared to 1.72 mg/L at pH 6. However, a lower pH increased pore-water metal concentrations and overlying water concentrations in bioassays. Hydrogen ion competition on metal receptor sites in C. crassiforceps was proposed to explain the decrease in toxicity in response to increased H+ activity. This study highlights the need to consider site-specific physicochemical conditions before applying generic risk assessment methods.     

Copper Bioavailability in Steilacoom Lake Sediments

Sediments were collected from Steilacoom Lake, Pierce County, in Washington State, and amended with copper sulfate (nominal concentrations of 800, 1,000, 1,500, and 2,000 mg Cu/kg dry weight) to assess copper bioavailability to Hyalella azteca, Chironomus tentans, or Ceriodaphnia dubia. H. azteca survival and C. tentans survival and growth were not significantly affected, with 10-day no observed effects concentrations (NOEC) and lowest observed effects concentrations (LOEC) of 2,010 and >2,010 mg Cu/kg, respectively. C. dubia was the most sensitive organism tested with 10-day NOEC and LOECs for survival and reproduction of 906 and 1,469 mg Cu/kg, respectively. Sediment AVS concentrations were <0.15 μmol/g, while simultaneously extracted metal (SEM) concentrations were ≥5.71 μmol Cu/g. Dissolved interstitial water concentrations ranged from below detection (0.010 mg/L) to 0.24 mg Cu/L, with interstitial water toxicity units as high as 3.4. Based on this study, effects to C. dubia may occur at bulk sediment concentrations >906 mg Cu/kg. Further, AVS and interstitial water concentrations are not accurate predictors of copper bioavailability in Steilacoom Lake. Received: 9 April 1998/Accepted: 16 August 1998     

Effect of loading density on the acute toxicities of surfactants,copper, and phenol toDaphnia magna straus

The effects of various densities ofDaphnia magna on the acute toxicities of three surfactants, and copper, and phenol were evaluated in 48-hr static toxicity tests. LC₅₀ values were determined at six loading densities for each of the test materials. The mean LC₅₀ values (±1 SD) were 4.8 (0.29) mg/L, 0.62 (0.16) mgL and 0.24 (0.10) mg/L for the anionic, nonionic, and cationic surfactants, respectively. Toxicity values for copper averaged 0.026 (0.01) mg/L and those for phenol, 7.7 (2.2) mg/L. For the nonionic surfactant, copper and phenol there was a trend of increasing toxicity with decreasing density. The differences in LC₅₀ values were not biologically significant with the maximum difference being approximately three-fold.     

Toxicity of copper to the collembolan Folsomia fimetaria in relation to the age of soil contamination

The toxicity of copper to the collembolan Folsomia fimetaria L. was studied in soil incubated with copper sulfate for different periods before the introduction of collembolans, to assess the effect of aging of contamination on the toxicity of copper. Adult survival, reproduction, and juvenile size were assessed. No clear influence of differences in contamination age was detected. The data were compared with results from a study performed in soil sampled at an old copper-contaminated site. Large differences in effects existed between spiked soil and field soil when concentrations were expressed on the basis of total soil copper concentrations. EC(10) and EC(50) values for reproduction in spiked soil were ca. 700 and 1400 mg Cu/kg soil, whereas no effects were found in field soil at copper concentrations up to 2500 mg/kg. Most of the differences disappeared when effects were expressed as a function of 0.01 M CaCl(2)-extractable soil copper. the lack of effects in field soil could be explained from the fact that in this field soil the CaCl(2)-extractable concentration was never higher than one-third of the EC(50) estimated for tests in the laboratory spiked soils.     

Acute toxicities of four metals on the early life stages of the crab Chasmagnathus granulata from Bahía Blanca estuary, Argentina

Acute semistatic toxicity tests were carried out for 96 h with first zoeae and young crabs of Chasmagnathus granulata. Survival curves and LC50 (lethal concentration 50, the concentration which produces the death of 50% of the exposed population) indices for copper, zinc, cadmium, and lead were determined. Furthermore, mixture toxicity tests (Cd/Cu and Cd/Zn) with first-stage larvae were also carried out. The LC50-96 h values determined in this study were 1093.4 (881-1319) microg Pb2+ L(-1), 219.2 (188.9-248.9) microg Cu2+ L(-1), 172.1 (141.3-203.6) microg Zn2+ L(-1), and 47.8 (37.9-58.0) microg Cd2+ L(-1) for zoeae I and 130.1 (121.7-139.0) mg Cu2+ L(-1), 51.0 (41.9-61.6) mg Zn2+ L(-1), and 35.7 (30.1-41.9) mg Cd2+ L(-1) for young crabs. The LC50-96 h indices for mixture tests with zoeae I were 260.6 (227.3-286.3) microg Cd2+/Zn2+ L(-1) and 41.3 (37.4-60.7) microg Cd2+/Cu2+ L(-1). Cadmium presented the highest acute toxicity for both stages of the life cycle examined. The toxicity of the metals analyzed followed the order cadmium >zinc>copper>lead. First zoeae were more sensitive than young crabs to acute exposure to all metals analyzed. The young crabs were considered potentially dangerous agents of transference to the associated trophic chain because of their relatively elevated resistance and their capacity to bioaccumulate heavy metals in their tissues. Mixed toxicity tests carried out on first-stage larvae showed different kinds of interactions. Cadmium/copper presented an additive interaction trend while the mixture cadmium/zinc showed an antagonistic interaction.     

Copper in drinking water, Nebraska, 1994

In 1993, the levels of copper (Cu) in much of Nebraska's drinking water exceeded the U.S. Environmental Protection Agency's (EPA) action level of 1.3 mg/L. To determine the association of copper with gastrointestinal (GI) illness in August 1994 the authors interviewed persons living in households with 1993 Cu levels > 3 mg/L (51 households), 2-3 mg/L (54 households), and < 1.3 mg/L (43 households). Cases were defined as persons who had experienced the rapid onset of vomiting or nausea with abdominal pain during the preceding two weeks. To validate their exposure index, the authors immediately resampled drinking water in the households of 25 cases and 27 controls matched for age. Reassessment in December 1994 of the exposure and case status of the original cohort showed no association between copper in drinking water in 1993 and case status in 1994. The risk of GI illness seemed no greater with Cu > 3 mg/L (RR = 1.03; 95% CI = 0.43, 2.49) or 2-3 mg/L (RR = 0.50; 95% CI = 0.18, 1.41) than with Cu < 1.3 mg/L. The 1993 Cu concentrations could not be reproduced in August 1994; resampling in December 1994 again showed no association between GI illness and Cu exposure (RR > 1.3-2.9 mg/L, < or = 1.3 mg/L = 0.25, 95% CI = 0.10, 0.64, and RR > or = 3.0 mg/L, < or = 1.3 mg/L = 0.36, 95% CI = 0.09, 1.49).     

Genotoxic Effects and LC<Subscript>50</Subscript> Value of NaOCl on <Emphasis Type="Italic">Orthrias angorae</Emphasis> (Steindachner 1897)

Studies show that different organisms used as bio-indicators have indicated several genotoxic and mutagenic effects of disinfected waters. In this study, the 96 h LC(50 )mean value of NaOCl for Orthrias angorae was calculated to be 0.5509 mg/L. The results showed that NaOCl is highly toxic to O. angorae specimens. Statistical analysis demonstrated a significant increase in micronuclei after the induction of 0.5 mg/L NaOCl concentration after 36 h. The same increase has been reported for 0.37 and 0.5 mg/L NaOCl concentrations after 72 h. Even though the MN frequency of 0.37 mg/L was similar after 36 and 72 h, only 72 h micronuclei frequency was statistically significant. The 72 h MN frequency of the negative control group was smaller than 36 h MN frequency of the negative control group. This discrepancy has led to 72 h MN frequency being statistically significant. MN frequency of 0.25 mg/L NaOCl concentration was insignificant when compared to negative test groups. The benzene treatment also caused a significant increase (p < 0.01) in the frequency of micronucleated erythrocytes.     

Effects of Copper Sulfate on Typha latifolia Seed Germination and Early Seedling Growth in Aqueous and Sediment Exposures

The vascular macrophyte Typha latifolia Linnaeus (common cattail) may be a sentinel for evaluating potential phytotoxicity to rooted aquatic macrophytes in aquatic systems. To further evaluate the potential utility of this species, T. latifolia seed germination, shoot growth, and root elongation were measured in 7-day aqueous exposures using mean measured aqueous copper concentrations of 10.0, 23, 41, 62, 174, and 402 μg Cu/L, which were ≥ 62% of nominal concentrations. Seed germination and seedling shoot growth were not significantly affected by any of these copper concentrations as compared to controls. Mean measured no-observed-effect-concentration (NOEC) and lowest-observed-effect-concentration (LOEC) for root elongation were 18.6 μg Cu/L and 35.0 μg Cu/L, respectively. Seven-day sediment tests were conducted by amending uncontaminated sediments with copper sulfate to mean measured concentrations of 7.9, 17.1, 21.0, 51.2, 89.5, and 173.5 mg Cu/kg, which were ≥ 84% of nominal concentrations. Seed germination was not significantly different from controls. Mean measured NOEC and LOEC values for seedling shoot growth were 89.5 mg Cu/kg and 173.5 mg Cu/kg, respectively, and mean measured NOEC and LOEC values for root growth were 14.0 mg Cu/kg and 19.7 mg Cu/kg, respectively. These results demonstrate that T. latifolia early seedling growth can be utilized for assessing aqueous and sediment toxicity of copper. Received: 21 March 2000/Accepted: 28 August 2000     

Community-based randomized double-blind study of gastrointestinal effects and copper exposure in drinking water

We assessed gastrointestinal effects in 1,365 adults exposed to either < 0.01 (controls), 2, 4, or 6 mg copper/L of drinking water for 2 months in a randomized, double-blind community-based study. The risk of symptoms increased with increasing Cu exposure and decreased with time. The best model by counting-process analysis included Cu concentration and sex. The risk of symptoms remained significantly higher in women than in men during weeks 1-4 for all concentrations tested; at week 1 comparison with the < 0.01-mg/L group showed that differences became significant in women at 4 mg/L [relative risk (RR) = 1.53; 95% confidence interval (CI), 1.02-2.05), and in men at 6 mg/L (RR = 1.9; 95% CI, 1.02-2.79). At week 2 for men and week 4 in women, the Cu concentration required to obtain significant differences on symptom report was > 6 mg Cu/L. We conclude that exposure to Cu in drinking water results in gastrointestinal symptoms, which are modulated by Cu concentration, time, and sex.