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1.
Significantly higher contents of mercury were found in fungi growing in the vicinity of a large Finnish chlor-alkali plant than in a control area. The highest concentrations (72–200 ppm dry wt) were found in Agaricus-species. The mercury contents in mycorrhizal fungi did not generally exceed the Finnish safety limit of 0.8 ppm.  相似文献   

2.
Mercury levels in fish, water and sediments were determined during 1982 along a 600 km stretch of the North Saskatchewan River (NSR) in the province of Alberta. Migratory fish species such as goldeye, walleye and sauger in the NSR were found to contain total mercury levels ranging from 0.104 to 1.553 mg/kg (mean ≧ 0.5 mg/kg). Northern pike, white sucker, longnose sucker and northern redhorse sucker had total mercury levels ranging from 0.003 to 1.003 mg/kg (mean < 0.5 mg/kg) Regression analysis of the data revealed that neither the sex of the fish nor the location of the sampling site contributed significantly to the mercury burden in fish in the entire study section of the river. Sediment analysis showed a low and more or less uniform concentrations of mercury in Alberta (≦0.1 mg/kg). The total mercury in NSR water averaged 0.09 μg/L in upstream Edmonton and was found to elevate in downstream NSR (0.22 μg/L) near industrial discharge sites and agricultural runoff areas (mean = 0.20 μg/L). Calculated partition coefficients seem to group the fish into two categories, (i) goldeye, walleye and sauger (bioconcentration factor [BCF] =3?3.7×103 and (ii) northern pike, longnose sucker, white sucker and northern redhorse sucker (BCF=1.2?1.8×103).  相似文献   

3.
The effect of cadmium and of zinc on the rate of uptake of a pentose sugar xylose and an aminoacid tryptophan by the intestine of a teleost fish, Heteropneustesfossilis was studied under two experimental conditions. In the first, four concentrations of cadmium or zinc (1.0 mM, 0.1 mM, 0.01 mM and 0.001 mM) mixed with the nutrient solution were filled in the intestinal sacs, and the rate of absorption was recorded after 1 h at 23°C. In the second experiment fish were exposed by bath to a sublethal concentration of cadmium (0.26 mg/1) or zinc (4 mg/1) for 15 and 30 days and the rate of absorption of the two nutrients was measured. The activity of intestinal Na+, K+ activated adenosine triphosphatase was also assayed. The two heavy metals at all the four concentrations decreased the rate of intestinal transport of nutrients. Increase in the concentration of each of the heavy metals decreased the uptake of nutrients, but the decreases were not linear. The rate of intestinal absorption of the two nutrients was also reduced by exposure of fish to the heavy metals invivo. The activity of Na+, K+ ATPase decreased invitro with all four concentrations of cadmium and zinc and was diminished in fish exposed for 15 and 30 days. Of the two heavy metals, cadmium was more effective in reducing the rate of transport of xylose and tryptophan.  相似文献   

4.
The effect of five concentrations (10 mM, 1 mM, 0.1 mM, 0.01 mM and 0.001 mM) of mercury on the rate of absorption of glucose, fructose, glycine and tryptophan by the intestine of the fresh water murrel Channapunctatus has been studied. Intestinal absorption of these nutrients was also examined in fish exposed to a sublethal concentration (3 μg/l) of mercury for 15 and 30 days. Significant decrease was recorded in the rate of intestinal absorption of all the four nutrients with higher concentrations (10 mM, 1 mM and 0.1 mM) of mercury. 0.01 mM and 0.001 mM of mercury also reduced the transport rate but it was insignificant, except in case of tryptophan, where 0.01 mM of mercury also produced significant decrease. Exposure of fish by bath to mercury also resulted in significant decrease in the intestinal transport rate of all the four nutrients after 30 days.  相似文献   

5.
The kinetics of oxidation of methylhydrazine (MMH) and 1,1-dimethylhydrazine (UDMH) by dissolved oxygen in water has been measured at various acidities as a function of catalyst (cupric ion) concentration. In dilute solutions the oxidation occurs through a cupric ion catalyzed process as well as by an uncatalyzed step. The extent of formation of nitrosodimethylamine (NDMA) depends upon the initial UDMH concentration. In dilute solutions NDMA is not formed, but in more concentrated solutions, NDMA formation increases with increasing UDMH content, reaches a maximum at 60–80% UDMH (by volume) and then decreases. The NDMA yield appears to approximately parallel the viscosity of the medium, and it is speculated that the factors which control viscosity may also be responsible for governing NDMA formation.  相似文献   

6.
The photolysis of methyl 2-benzimidazolecarbamate (Carbendazim, 1) in methanol and in the presence of singlet oxygen, was studied. Dimethyl oxalate 4, 2-aminobenzimidazole 7, benzimidazole 9, N,N′-dicarbomethoxyguanidine 13, monocarbomethoxyguanidine 14, monocarbomethoxyurea 15, and 2-guanidinobenzimidazole 17, were isolated and identified in this reaction.A mechanism that accounts for the formation of the photoreaction products, is presented.  相似文献   

7.
8.
J.H. Canton  W. Slooff 《Chemosphere》1982,11(9):891-907
The toxicity of nitrolotriacetic acid (NTA), citrex-S-5, sodium alluminium silicate (NAS), carboxymethyloxysuccinate (CMOS), linear alkylbenzene sulfonate (LAS) and soap was examined using bacteria (Pseudomonasfluorescens), algae (Chlorellavulgaris and Microcystisaeruginosa), crustaceans (Daphniamagna), insects (Aedesaegypti), fishes (Poeciliareticulata and Oryziaslatipes) and amphibians (Xenopuslaevis). The biodegradability of NTA, citrex-S-5, CMOS and LAS was studied in the OECD-test.The acute toxicity of the compounds differed largely with the organisms tested (up to a factor 1,000). Based on the results of the short-term toxicity tests (with all test organisms) and the long-term toxicity tests (with Daphniamagna and in case of LAS also with Poeciliareticulata) the following no-observed-effect concentrations (NOEC) could be derived: LAS 3.2 mg/1; NAS and soap 10 mg/1; CMOS 32 mg/1; NTA 100 mg/1 and citrex-S-5 320 mg/1. However, testing different samples of one test compound may result in marked differences in toxicity (e.g. NAS: a factor 32).All compounds tested showed to be biodegradable as the percentage DOC decreased more than 80% within four weeks. CMOS biodegraded quickly, whereas citrex-S-5 and LAS showed a somewhat slower rate of degradation. In contrast to the other compounds NTA required an adaptation period of 1 week.  相似文献   

9.
For the determination of the quantum yields of 1,2,3,4,7-pentachlorodibenzo-p-dioxin (1) and 1,2,3,4,7,8-hexachlorodibenzo-p-dioxin (2), ten Pyrex glass photochemical cells were constructed and their correction factors determined. Quantum yields at 313 nm for 1 and 2 in aqueous acetonitrile (4:6 v/v) were (9.781 ± 2.376) 10?5 and (1.096 ± 0.020) × 10?4, respectively. These quantum yields and the measured absorption spectra were used to estimate the environmental phototransformation first-order rate constants and photochemical half-lives of 1 and 2 in water under conditions of variable sunlight intensity during various seasons from solar intensity data available in the literature. In summer, typical half-lives for the phototransformation of 1 and 2, respectively, near the surface of water bodies at 40° north latitude would be 364 ± 88 and 151 ± 3 h; whilst such values in winter would be 1257 ± 309 and 518 ± 10 h.  相似文献   

10.
Uptake, clearance and extent of metabolism of 14C-labelled t-butylphenyldiphenyl phosphate (t-BPDP), tri-m-cresyl phosphate (mTCP), tri-p-cresyl phosphate (pTCP) and triphenyl phosphate (TPP) were studied in rainbow trout (Salmogairdneri) and fathead minnows (Pimephalespromelas) using short-term static exposures (50 and 5 μmg/L). Bioconcentration factors for pTCP, mTCP, TPP and tBPDP calculated by use of total radioactivity in whole fish were 1420, 784, 573 and 1096 respectively, for rainbow trout and 928, 596, 561 and 1010 respectively, for fathead minnows. Differences in rates of clearance and biotransformation among the four compounds were more closely related to their ease of hydrolysis than to hydrophobicity.  相似文献   

11.
Experiments were conducted to determine the factors responsible for the loss (adsorption, chemical hydrolysis, microbial degradation, etc.) of dichlorvos (2,2-dichlorovingl 0,0-dimethyl phosphate) in soil perfusion systems of Houston Black clay. The rate of disappearance from the perfusate (hence the rate of dichlorvos degradation in soil) was related directly to the presence of Bacilluscereus in the perfusion system, the pH of the system, and the extent of dichlorvos adsorption. Gas liquid chromatographic analyses of the perfusates showed that dichlorvos disappearance was rapid when B. cereus was added to a previously sterilized soil perfusion system (50% in 3.9 days). Under sterile conditions, 50% of the added dichlorvos was recovered after 10 days. When B. cereus was added to a mineral salts medium containing dichlorvos as sole ccrbon source, 49% of the initial dichlorvos concentration was degraded in 4 days. The organism was not capable of utilizing dichlorvos as a sole phosphorus source. Chemical hydrolysis of dichlorvos in aqueous, buffered, soil-free systems showed that hydrolysis did not occur in very acid systems (<pH 3.3), but increased with increasing pH values (26% in 4 days at pH 6.9), and was rapid at pH 9.3 (> 99% in 2 days). The extent of dichlorvos adsorption was determined by comparing the initial loss of dichlorvos in a sterile, soil-free extract solution with the initial loss in a sterile soil perfusion system. The rapid initial disappearance of dichlorvos in the presence of sterilized soil was attributed to soil adsorption of the pesticide. After 10 days both systems contained equal concentrations (50%) of dichlorvos. Non-biological mechanisms accounted for 70% of the total degradation of dichlorvos, while bacterial degradation accounted for 30% in the soil perfusion systems.  相似文献   

12.
Aliphatic hydrocarbons and non-polar aromatic compounds have been analyzed after a spill of grude oil at Baltic Sea 1979 from drifting weathered oil glumps, sediment and sediment trap samples and bivalves at five areas of the Finnish Archipelago Sea. Mytilus and flounder muscles and flounder livers were analyzed 1980 and 1981 from three of the previous five areas. The glumps were shown to be weathered grude oil. Sediment trap samples on the visibly contaminated area contained higher amounts of oil residues and in different ratios than the bottom sediments at the same areas. Extra local aliphatic hydrocarbon pollution was detected from the sediment traps at the reference area. Bivalves contained high amount of oil residues at visibly polluted but in some visibly non-polluted areas also 1979. Any significant decontamination was not detected at summer 1979 but next year the Mytilus samples contained only traces if any and 1981 no detectable levels of aromatic oil residues. Aliphatic hydrocarbon residues in flounders showed no regional differences and no significant change of levels between 1980 and 1981. In contrary, the aromatic oil residues decreased to the non-detectable level in flounder muscles and to a significantly lower level in flouder livers 1981 related to 1980. Linear correlations of the analysis results are discussed.  相似文献   

13.
A single intraperitoneal administration of tin (II) tartrate to albino rats (2 mg Sn++100 g body wt) depressed the levels of hepatic glutathione reductase, glucose-6-phosphate dehydrogenase, lactate dehydrogenase, succinic dehydrogenase, reduced glutathione (GSH) and total sulfhydryl contents and led to an elevated level of tin. Serum aminotransferase levels were however, not affected but an increase in serum bilirubin and calcium levels was noticed.Invitro studies showed that tin tartrate upto a concentration of 2 uM did not affect the activity of liver enzymes tested, when the enzyme preparations were incubated with metallic salts during the time of assay. The critical concentration of tin for these parameters was at 5 uM.  相似文献   

14.
Population of microorganisms able to degrade 2,4-D (2,4-dichlorophenoxyacetate) were estimated in 4 non-rhizosphere and 5 rhizosphere soils in Natal by a most probable number (MPN) method using 2,4-D-bromocresol purple media to show 2,4-D degradation with the formation of HC1. Confirmation of herbicide degradation in acid 2,4-D tubes was required by subculturing into fresh 2,4-D-and control indicator media. The MPN estimates of 2,4-D-degrading organisms per g of corresponding rhizosphere/control soils were 6100/212 with African clover (Trifolium africanum L.) soils, and 46400178, 1560001480 and 407006170 with sugarcane (Saccharum officinarum L.) soils. The high, stimulated populations of 2,4-D-degrading microorganisms in the sugarcane rhizospheres suggest the possibility of rapid degradaton in the rhizosphere as an additional mechanism for the protection of certain plants against soil-applied herbicides.  相似文献   

15.
Photolysis (254 nm, 72h) of 1-nitro-2-phenylnaphthalene 1 in methanol gave 2-phenyl-1,4-naphthoquinone-4-monoxime 2, 2,2′-diphenyl-4,4′-binaphth-1,1′-diol 3 and 2,2′-diphenyl-4,4′-binaphth-1,1′-dione 4. Straightforward reactions available to the environment account for the formation of the products: (a) isomerisation of the nitro compound into a nitrite ester followed by either (a) migration of the nitroso group and isomerisation into the oxime 2 or (b) oxidative coupling and solvolysis into the binaphthol 3 and followed by oxidation into the binaphthone 4.  相似文献   

16.
This study described an invitro experiment on biotransformation of 2,6-DIPN in carp hepatopancreas. It has already been revealed by the previous invivo studies to be metabolized with enzymatic oxidation in the liver and been postulated a metabolic pathway. These results were confirmed by means of incubation with 2,6-DIPN in carp hepatic microsome preparation with NADPH, and G-6-P as co-factor. It was suggested that DIPN may be mainly metabolized in the hepatic cytochrome P-450 in the microsomes system. The kinetic parameters i.e. apparent Michaelis constant (Km) and maximum velocity (Vmax), in the metabolites formation were also calculated.  相似文献   

17.
P. Miramand  M. Unsal 《Chemosphere》1978,7(10):827-832
Acute toxicity of vanadium to some marine benthic and phytoplanktonic speciesThe acute toxicity of vanadium as sodium metavanadate to three benthic (Carcinusmaenas, Mytilusgalloprovincialis, and Nereisdiversicolor) and three phytoplankton species (Dunaliellamarina, Prorocentrummicans and Asterionellajaponica) were studied. In general the phytoplankton were found to be more sensitive than the benthic organisms used in our experiments. Considering the results from LC50 (9 days) experiments, the organisms, can be classified in the following decreasing order of sensitivity: D. marina (0.5 ppm), A. japonica (2 ppm), P. micans (3 ppm), N. diversicolor (10 ppm), C. maenas (35 ppm), M. galloprovincialis (65 ppm).  相似文献   

18.
A mixture of ten metals (As, Cd, Cr, Cu, Fe, Pb, Hg, Ni, Se and Zn) at the Great Lakes Water Quality Objective levels was found to reduce the primary productivity of four cultured freshwater algae (Scenedesmus, Chlorella, Anabaena and Navicula) as well as natural phytoplankton from Lake Ontario water. The metal mixture also caused a reduction in the reproduction and transport of an amino acid analogue (α-aminoisobutyric acid) by Ankistrodesmus. The depuration and exchange of the amino acid analogue were not affected by the metal mixture. The nitrogenase activity of Anabaena was, however, reduced in the presence of the metal mixture.  相似文献   

19.
20.
Daniel Barug 《Chemosphere》1981,10(10):1145-1154
The degradation of the biocide bis (tributyltin) oxide by pur cultures of microorganisms has been studied. Attempts to isolate microorganisms able to utilize bis (tributyltin) oxide as sole carbon source, were unsuccessful. Of many bacterial species investigated Pseudomonas aeruginosa and Alcaligenes faecalis degraded sublethal amounts of bis (tributyltin) oxide during aerobic growth in the presence of suitable carbon sources. P. aeruginosa converted bis (tributyltin) oxide into monobutyltin and small amounts of dibutyltin derivatives. Similar results were obtained with growing mycelium of Coniophora puteana, Trametes versicolor and Chaetomium globosum. Microbial conversion of monobutyltin trichloride was not observed. Dibutyltin dichloride was converted into monobutyltin derivatives under certain sterile conditions.  相似文献   

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