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141.
采用美国惠普公司MC/GS联用仪,对鸭绿江(丹东段)江水中有机污染物种类、组成进行了分析鉴定,进而采用高压液相色谱法对多环芳烃类进行定量测定与评价,进行了该江段有毒有机物名录筛选,提出由27种有毒有机污染物组成的名单。  相似文献   
142.
This study was a preliminary step to evaluate the acute toxicity of 1-methyl-3-octylimidazolium chloride ([C8mim]Cl) on loach (Misgurnus anguillicaudatus) by determining the effects on hepatic antioxidant enzyme activities and by the comet assay. The results showed that [C8mim]Cl had acute toxicity at concentrations above 20 mg L?1, inducing oxidative stress and genotoxicity on fish liver cells. In respect to enzyme activities, [C8mim]Cl induced changes in the activities of superoxide dismutase, catalase, and glutathione content the livers of fish exposed at 20–80 mg L?1. [C8mim]Cl at the same exposure level caused a remarkable increase in malondialdehyde level. The comet assay indicated that [C8mim]Cl at 20–80 mg L?1 induced genotoxicity in liver cells. With increased exposure concentration and time, the two comet parameters trailing rate and tail moment were significantly increased, with significant differences (P < 0.05) observed between control group and each treatment group. The present study shows that ionic liquids can be a threat to the health of aquatic organism when accidentally released to aquatic ecosystems.  相似文献   
143.
The microcrustacean Thamnocephalus platyurus was used to detect the toxicity reduction of carboxin in abiotic degradation compared to biotic degradation. The abiotic degradation was obtained using two sterilized Entisols with different surface properties while the biotic degradation by Pseudomonas aeruginosa was obtained using the fungicide as the only C source. The results showed that the highest toxicity reduction rates for the abiotic degradation were achieved in 20 days with 49.2% for the coarser soil, 60.7% for the soil with a finer texture, whereas for the biotic degradation, 60.6%. Analysis (1H NMR) showed that the soils transformed carboxin to produce sulfoxide and enol in different concentrations depending on the soil properties, while P. aeruginosa metabolized the fungicide to produce inorganic compounds such as ammonium and nitrite, minor degradation pathways were oxidized to sulfoxide and hydrolytic ring-opening to 2-[(2-hydroxyethyl)thio]acetoacetanilide enol. These results indicated that the degradation of carboxin occurred via abiotic catalytic processes as well as via biotic transformation leading to less toxic derivatives and such phenomena are caused by exchange/surface features of soils, rather than by the mere content of clay or organic matter fractions.  相似文献   
144.
利用发光菌和大型蚤对北方某城市再生水急性毒性的调查   总被引:1,自引:0,他引:1  
利用发光菌和大型蚤作为受试生物测定了北方某城市5个再生水原水(城市污水厂二级出水)和2个再生水处理系统的各工艺出水的急性毒性.结果表明,各再生水原水对大型蚤和发光菌具有不同程度的毒性效应,其中工业废水占较大比例的K和B厂再生水原水的大型蚤48 h总抑制率分别高达90%和100%,发光菌发光抑制率分别达到74.2%和46...  相似文献   
145.
Abstract

Standardized tests were applied to aromatic and polar fractions of sediment extracts to determine whether polar constituents or oxidative degradation products contributed significantly to the toxicity of sediments oiled by the Exxon Valdez spill. Intertidal sediment and pore-water samples were collected in September 1990 from two heavily oiled sites and an unoiled site in Prince William Sound (PWS). Methylene chloride extracts from these samples were fractionated by liquid chromatography into aliphatic, aromatic and polar fractions, and the aromatic and polar fractions were tested for toxicity using the MicrotoxR test, bivalve larval mortality and development (Mytilus); several measures of genotoxicity in Mytilus, including SOS ChromotestR, anaphase aberrations and sister chromatid exchange; and survival, anaphase aberrations and teratogenicity in coho salmon (Onchorhynchus kisutch). MicrotoxR and SOS ChromotestR protocols were applied in a screening mode to all samples, whereas other tests were applied only to selected fractions from two sites. Samples from Bay of Isles (oiled) were consistently more toxic (usually only 2 to 5-fold) than the Mooselips Bay (unoiled) samples, which gave very low responses in all tests. for both sites, however, responses to polar and aromatic fractions were about the same in most tests, suggesting that while the overall toxicity of the oil was low in these samples, at least part of that toxicity was derived from polar constituents. Compared to the parent hydrocarbons, polar oxidation products partition preferentially into pore-water and are more rapidly diluted and dispersed in the water column. These results suggest that polar oxidation products of petroleum hydrocarbons pose little risk to marine organisms, except possibly for infauna continuously exposed to pore-water in heavily oiled sediments. Independent surveys showed that sediment toxicity in PWS declined during 1989–1991 to near background levels, in accord with previous understanding of oil weathering and toxicity.  相似文献   
146.
Abstract

This study assessed the long-term toxicity of chlorpyrifos on survival and reproduction of Banded Gourami by using mortality, gonado-somatic index (GSI) and histopathological observations as endpoints. Adult fish were exposed to five different concentrations of chlorpyrifos (0, 15, 50, 150, 500?µg/L) in 15 PVC tanks for 15, 30, 45, 60 and 75?days. Results showed that all male and female fish died after 15?days of 500?µg/L chlorpyrifos exposure. No consistent significant effect was observed for both male and female GSI. Furthermore, results showed dose- and time-dependent histopathological alterations for both ovary and testes. The 60-d No Observed Effect Concentration (NOEC) for most histopathological alterations of Banded Gourami ovary and testes was 50?μg/L, while 60-d NOEC for mortality of both male and female fish was < 15?μg/L. The results show that the long-term exposure to chlorpyrifos not only affect the reproductive tissues of Banded Gourami at exposure concentrations but also cause their mortality. Future studies should evaluate effects at lower concentrations.  相似文献   
147.
The toxicity of oil sands process-affected water (OSPW) has regularly been attributed to naphthenic acids, which exist in complex mixtures. If on remediation treatment (e.g., ozonation) or on entering the environment, the mixtures of these acids all behave in the same way, then they can be studied as a whole. If, however, some acids are resistant to change, whilst others are not, or are less resistant, it is important to establish which sub-classes of acids are the most toxic.  相似文献   
148.
文章论述了二的化学成分及主要来源 ;二的毒性 ;日本、美国、德国等国二恶英污染状况及各国制定的标准  相似文献   
149.
以江苏省常州市城北污水算处理厂的进水、活性污泥处理系统的出水以及A^2O处理工艺的出水为研究对象,对进出水进行Daphnia magna急性毒性试验。结果表明,进水对Daphnia magna具有24h急性毒性,经过活性污泥处理工艺处理及A^2O处理工艺处理,两股出水均不显示24h急性毒性,采用毒性鉴别评价(Toxicity Identification Evaluation,TE)方法对进水进行监测和评价,发现曝气可去除进水的毒性,C18固相提取亦可去除进水毒性,进水中存在的主要毒物为易挥发的非极性有机化合物,进一步检测可知,进水中的关键毒物主要为邻丙基甲醛肟、1,1-甲基乙基-2-甲氧基苯酚、2-氮,氮二甲基苯甲醇等,此外,对2个处理系统出水进行GC/MS分析,可知出水中关键毒物基本被去除。  相似文献   
150.
In 1996 the Swedish Poisons Information Centre performed a follow-up study concerning poisonings related to ‘do-it-yourself’ activities. The study was supported by the National Institute of Public Health in Sweden. The objectives were to investigate and define monthly variations, route of exposure, type of products and, in particular, exposures to corrosives, age and sex groups, place of treatment, severity of symptoms, place of the accident, special risk products and risk situations. The Poisons Information Centre was contacted concerning 1609 cases, with a peak during the summer months. There was no or uncertain connection between exposure and symptoms in 117 cases. This means that 1492 cases were left to study. Inhalation and eye exposure were the predominant routes, followed by skin exposure and ingestion. Cleaning agents were the most common type of products involved. Of the 1492 cases included in the study 1033 were possible to follow up. Among these, 20–29 year olds and 30–39 year olds predominated, and there was a dominance for men. In total, 28% of those exposed were subject to medical attention, either in hospital or in outpatient clinics. According to the Poisoning Severity Score 78% had mild (grade 1) and 7% moderate (grade 2) symptoms. There were no severe intoxications and no deaths. Severity grade 2 occurred 3.6 times more often among those with exposures involving risk of corrosive damage than among others in the study population. Most accidents occurred in the home. Special risk products and risk situations were exposure to corrosive products, release of chlorine when mixing hypochlorite and acid, ‘fire-eating’, siphoning gasoline and diesel fuel, welding, and inhalation of carbon monoxide from exhaust gases. The Swedish Poisons Information Centre registered 1609 cases of poisoning accidents during ‘do-it-yourself’ activities, which means an average of four to five cases per day. Although this type of accidents is not uncommon, significant poisoning seems to be rare. Some special risk situations were identified.  相似文献   
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