International standardized procedures for in vivo evaluation of multi-walled carbon nanotube toxicity in water

The classical approach in ecotoxicological evaluation of chemical substances consists of conducting standardized bioassays on organism models. In this work, the potential impact of industrial multi-walled carbon nanotubes was investigated by ecotoxicological standardized procedures using aquatic organisms of different trophic levels, namely bacteria, green algae, invertebrates, fish, and amphibians. The results indicated (1) inhibition of growth in amphibians at 50 mg L^?1 and higher, and (2) no effects on daphnia and fish up to 100 mg L^?1. With the exception of algae (for which Fe deficiency is measured), it seems that the observed toxicity may be due to physiological effects in relation to the ingestion of carbon nanotubes not necessarily related to their intrinsic effects.     

重金属（Hg，As，Pb）污染对蚕豆根尖细胞微核的诱变研究

采用蚕豆根尖细胞微核检测技术,分别探讨不同浓度的HgCl2、As2O3、Pb（NO3）2对蚕豆根尖细胞微核率的影响。以蒸馏水处理作为阴性对照实验。结果表明不同浓度的HgCl2可使蚕豆根尖细胞微核率明显上升,说明HgCl2对蚕豆根尖具有明显的毒性效应——诱发突变（微核）。不同浓度As2O3可使蚕豆根尖细胞微核率明显上升。说明三氧化二砷（As2O3）对蚕豆根尖具有明显的毒性效应——诱发突变（微核）。蚕豆根尖微核率在铅离子浓度0—25mg／L范围内,随着硝酸铅处理浓度的升高而升高,说明硝酸铅是一种较强的诱变剂。     

Lipid peroxidation rates in <Emphasis Type="Italic">Taraxacum officinale</Emphasis> Wigg. and <Emphasis Type="Italic">Vicia cracca</Emphasis> L. from biotopes with different levels of soil pollution with heavy metals

The rates of lipid peroxidation (LPO) have been studied in Taraxacum officinale Wigg. (Asteraceae) and Vicia cracca L. (Fabaceae) from urban ecosystems with different levels of soil pollution with heavy metals (HMs), including Pb, Zn, Cu, and Cr. The former species responds to the increased HM contents by intensification of LPO processes, with their parameters correlating with the concentrations of Pb, Zn, and Cu in the soil. In the latter species from the same biotopes, conversely, LPO homeostasis remains actually undisturbed.     

Evaluation and quantification of genotoxicity of urban waters by using Vicia faba bioassays

The ecotoxic effect of pollutants in the water environment has become a hot topic of research. Because of the genotoxicity describing the composite deleterious action of the toxicants in water, the Vicia faba root-tip cell micronucleus (MN) test was applied for genotoxicity assessment of organic and inorganic substances in four rivers, two lakes and effluent flows from two wastewater treatment plants in Xi’an, China. Results showed that the lowest MN frequency was between 2.0‰ and 3.0‰. However, the highest MN frequency of the water samples was as high as 30.0–34.0‰. The results well reflected that the seriously polluted river with high chemical oxygen demand and total organic carbon showed high genotoxicity, and also indicated the genotoxic impact of urban discharge on the surface waters and the ability of urban water bodies to absorb the impact. In addition, there were significant correlations between the genotoxicity expressed by MN rate and Cr⁶⁺ (5–80?mg/L) and phenol concentrations (2–40?mg/L). The genotoxicity of the urban water could be quantified as equivalent Cr⁶⁺ or phenol concentrations and which might be used as a set of quantitative indicators of the water genotoxicity.     

用SOS/Umu生物测试评价北方某自来水厂对遗传毒性物质的去除效果

大量研究表明,饮用水中存在着能导致遗传毒性的物质,在我国许多水厂水质检测能力有限的前提下,生物毒性指标作为反映有毒物质综合指标具有重要的现实意义.本研究应用SOS/Umu生物毒性测试评价了北方某市一自来水厂的A、B、C、D 4套试验工艺在不同的季节(冬春两季)各工艺段出水的遗传毒性效应.结果显示,冬春两季地表水加氯后遗传毒性效应均显著增加,冬季间接遗传毒性效应高于春季;活性炭吸附对去除遗传毒性物质效果显著,但后期加氯使遗传毒性效应增加;冬春两季比较,以及地下水和地表水比较,各工艺出水的遗传毒性效应差别很大.通过研究表明,本研究所应用的生物毒性测试SOS/Umu能够快速、准确地对水厂工艺过程中致突变物质的处理效果进行评价,能对工艺改进提出指导,是自来水质安全性评价的重要补充手段.     

除草剂异丙莠诱发蚕豆根尖细胞遗传损伤的研究

以蚕豆根尖为材料,研究除草剂异丙莠对蚕豆根尖细胞的遗传毒性效应。采用蚕豆根尖微核技术,以不同浓度的异丙莠为诱变剂,测定蚕豆根尖细胞的有丝分裂指数、微核率和染色体畸变率。结果表明,异丙莠能诱发较高频率的微核率,即在一定浓度范围内,其微核率随异丙莠处理浓度的升高而增加,但随着异丙莠浓度进一步升高而呈下降趋势;异丙莠能降低蚕豆根尖细胞有丝分裂指数并诱导染色体产生多种类型的畸变。一定剂量的除草剂异丙莠对蚕豆根尖细胞具有明显的遗传毒性。     

In situ bioassays with Chironomus riparius larvae to biomonitor metal pollution in rivers and to evaluate the efficiency of restoration measures in mine areas

In this study we evaluate the ability of an in situ bioassay with Chironomus riparius larvae, using larval development and growth as endpoints, to biomonitor water quality and to assess the biological recovery of metal contaminated freshwater ecosystems of mine areas that are subject of restoration measures. The bioassay was carried out in streams located near an abandoned goldmine in North Portugal, throughout an environmental rehabilitation of the mine (2002-2004). During this period, a decrease in the inhibition of larval growth in the metal contaminated stream was observed. The bioassay was also performed in streams located near an active tungsten mine in Central Portugal. Larval growth and development were highly inhibited in the stream that receives acid drainage from the tungsten mine and treated water from the AMD treatment station. The results indicate that the bioassay can be used to evaluate the efficiency of environmental restoration measures in mining areas.     

Comparison of solid-phase bioassays and ecoscores to evaluate the toxicity of contaminated soils

Five bioassays (inhibition of lettuce germination and growth, earthworm mortality, inhibition of springtail population growth, avoidance by springtails) were compared, using four coke factory soils contaminated by PAHs and trace elements, before and after biotreatment. For each bioassay, several endpoints were combined in an ‘ecoscore’, a measure of test sensitivity. Ecoscores pooled over all tested bioassays revealed that most organisms were highly sensitive to the concentration of 3-ring PAHs. When four soils were combined, behavioural tests using the springtail Folsomia candida showed higher ecoscores, i.e. they were most sensitive to soil contamination. However, despite overall higher sensitivity of behavioural tests, which could be used for cheap and rapid assessment of soil toxicity, especially at low levels of contamination, some test endpoints were more sensitive than others, and this may differ from a soil to another, pointing to the need for a battery of bioassays when more itemized results are expected.     

Profile and removal of endocrine disrupting chemicals by using an ER/AR competitive ligand binding assay and chemical analyses

An estrogen receptor (ER)/androgen receptor (AR) ligand competitive binding assay (ER/AR-binding assay) and chemical analyses were used to evaluate the endocrine disrupting chemicals (EDCs) behavior of two municipal wastewater treatment plants (WWTPs) (K and S). In the influents, estrone (E1), androsterone (A), androstenedione (AD), BPA (bisphenol A), NP (nonylphenol) and daidzein (DZ) were detected in high amounts with subsequent 24 h-average concentrations of 350, 1000, 29, 1300, 3900, and 5700 ng/L in K-WWTP and of 310, 620, 59, 1600, 2600, and 8400 ng/L in S-WWTP. The estrogenic (androgenic) activity as 17 -estradiol (E2) equivalents (EEQ) or testosterone (Te) equivalents (TEQ) was consequently 620 ng E2/L (570 ng Te/L) and 580 ng E2/L (800 ng Te/L) for the two WWTPs. The removal e ciencies of the above mentioned sole target chemicals were 51%–100% for K-WWTP and 55.6%–100% for S-WWTP. The removal e ciencies of EEQ were about 73% for both WWTPs, while the removal e ciencies of TEQ were 62.1% for K-WWTP and 98.4% for S-WWTP. In addition, chemical-derived EEQ were about 1.2%–52.4% of those by ER-binding assay for K-WWTP and the corresponding ratios were 1.3%–83.3% for S-WWTP, while chemical derived TEQ were less than 3% of values measured by the AR-binding assay for both WWTPs.     

土壤镉污染毒性效应的多指标综合评价

以草甸棕壤为供试土壤,以蚕豆幼苗根尖有丝分裂指数、染色体畸变率以及微核率,幼苗叶片内抗氧化酶活性、植物内源激素含量为指标,采用盆栽方法研究了0～10 mg·kg^-1镉胁迫对植物细胞的遗传和生态毒性效应.结果表明,在此浓度范围内,蚕豆根尖细胞有丝分裂指数、染色体畸变率以及微核率均随镉浓度增加呈显著的剂量-效应正相关关系,其中微核率变化最为明显,处理组微核率分别为对照组的1.43～3.22倍;蚕豆幼苗叶片内的SOD和POD活性变化呈先升高后下降的趋势;而CAT活性随镉浓度增加其变化规律与SOD、POD相反.此外,镉胁迫下植物激素脱落酸(ABA)、赤霉素(GA₃)与细胞分裂素类的玉米素和玉米素核苷总含量(Z&ZR)均表现出低浓度下诱导和较高浓度下诱导率降低的趋势,在镉浓度为2.5 mg·kg^-1时３种植物激素含量均达到最高值,分别比对照组增加了6.6%、 4.0%和12.6%.研究表明,各指标对污染物的毒性具有响应且响应的域值及其敏感度不同,将各指标综合使用可使土壤镉污染的遗传和生态毒性诊断更为有效.