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1.
The amount of Cd and Pb in full blood and in the urine of males in Cracow and in a control area were measured and compared to the background of the level of these metals in air, dust fall and drinking water. The investigations were carried out in the years 1984–85. The mean Cd level in body fluids of Cracow's inhabitants was significantly higher than in the control group, and it amounted to: 0.54 μg Cd 100 mL?1 in blood and 2.13 μg Cd L?1 in urine. The Pb content in blood of the Cracow group (15.74 μg 100 mL?1) was also significantly higher than in the control one, while the Pb level in urine was similar in both populations, reaching values below 10 μg L?1. The mean annual Cd concentration in air and the Cd content in the dust fall in Cracow were 3 times higher than in the control area. The mean annual Pb concentration in Cracow's air exceeded the permissible Polish norm. In comparison with the control area, the Pb concentration level in air and its content in the dust fall in Cracow were 5 and 2 times higher, respectively. The level of Cd and Pb concentration in drinking water in Cracow and in the control area were much lower than the permissible values; however, in Cracow they were somewhat higher than in the control area.  相似文献   

2.
The effects of four concentrations (0.5, 1, 5 and 10 μg mL?1) of the heavy metals Hg, As, Pb, Cu, Cd, and Cr on some senescence variables of Cuscuta reflexa Roxb. were studied. All of the treatments, except 0.5 μg mL?1, decreased Hill reaction activity, chlorophyll and protein contents and dry matter percentage in biomass and increased tissue permeability over control data. The harmful effects of the metals were best visible at 10 μg mL?1. The general order of sensitivity was As > Cd > Pb > Hg > Cu > Cr (absolute metal concentration). The data suggest that Cuscuta reflexa shows tolerance to the heavy metals tested up to 0.5 μg mL?1.  相似文献   

3.
The aquatic vascular plant (Ceratophyllum demersum L.) was investigated as a potential biological filter for removal of Cd from wastewaters. Plants were grown in and harvested weekly from 0.10 M Hoagland nutrient solutions containing concentrations of Cd from 0.01 to 1.03 μg Cd mL?1. Tissue Cd was positively correlated to increased concentrations of Cd in solution. Concentration factors (CFs) of Cd in plants after one week were 13.3 for the 0.01 μg Cd mL?1 treatment; 451.4 for plants treated with 0.04 μg Cd mL?1, and 506.5 for plants treated with 1.03 μg Cd mL?1. Plants treated with 0.01 μg Cd mL?1 sustained tissue Cd concentrations almost 9-fold over those at week 1. However, after 5 weeks tissue Cd concentration in plants exposed to 1.03 μg Cd mL?1 had decreased 97% compared to the week 1 concentration. Growth measurements of dry weight, stem lengths, and lateral shoot growth were nagatively correlated to increased Cd treatments. Our results suggest that Coontail exposed to very low Cd concentrations (0.01 μg Cd mL?1) can take up and accumulate Cd. However, plants exposed to Cd at 0.04 μg Cd mL?1 or above did not accumulate Cd past one week.  相似文献   

4.
The side effects of fluazifop-butyl on soil fungal populations and oxygen uptake were studied by incubating soil samples with a range of fluazifop-butyl concentrations (0, 0.6, 3 and 6 μg g?1) over 8 weeks. Cellulose decomposition in soil was also studied in laboratory experiments with the herbicide which was either incorporated in soil or sprayed onto calico squares which were buried in soil. The mycelial dry weight of six fungal species under the effect of the herbicide was also examined. Fluazifop-butyl had no significant effect on total fungal propagule populations at 0.6 μg g?1. At 3 and 6 μg g?1, it caused temporary reduction in fungal populations observed after 1 and 2-wk of incubation. The herbicide had no significant effect on OZ uptake. The decay of calico buried in herbicide-treated soil was generally stimulated, while the decomposition of herbicide-treated calico, buried in untreated soil, was temporary delayed. The mycelial dry weight yields of Aspergillus favus (at 2 and 12 μg mL?1 of fluazifop-butyl) and Cunninghamella echinulata (at 12 μg mL?1) were significantly increased. At 24 μg mL?1 the mycelial dry weight of A. flavus and Alternaria alternata was significantly reduced.  相似文献   

5.
Azaarenes are one of several classes of organic compounds which contain mutagenic and carcinogenic substances that are found in synthetic fuels effluents. This study investigated the potential for a mutagenic azaarene, acridine, to accumulate in freshwater fish (Pimephales promelas) via four possible pathways: (1) direct uptake from water, (2) uptake via interaction with contaminated sediments, (3) uptake via ingestion of contaminated zooplankton (Daphnia pulex), and (4) uptake via ingestion of benthic invertebrates (Chironomus tentans) living in contaminated sediments. The results showed that acridine was rapidly accumulated from water by fathead minnows. Equilibrium concentration was attained within 24 h at a concentration factor ([acridine]fish, wet wt/[acridine]water) of 125±10. Depuration was rapid and appeared to occur in two stages, with a net elimination rate of 0.23 h?1 [acridine]fish at equilibrium. Equilibrium concentration factors of 51±5, 30±2, and 874±275 were observed forChironomus, Daphnia, and sediment, respectively. The calculated rates of uptake of acridine via ingestion of contaminated invertebrates (0.02 μg g?1 h?1) and ingestion of sediment (0.01 μg g?1 h?1) were negligible compared with direct uptake from water (1.40 μg g?1 h?1) in a hypothetical system with all compartments in equilibrium.  相似文献   

6.
Samples of soils and vegetation from the mining area of South-West Sardinia (Italy) were analyzed for Pb, Zn, Cd, and Cu content. The area (more than 100 km2) is inhabited by many thousands of people; land utilization includes mainly grapes on some small plains and permanent sheep pasture on the hills. The levels of Pb, Zn, and Cd were found to be exceptionally high in most samples. Lead concentration was up to 71000 μg g?1 in the soils and 4000 jig g?1 in vegetation; Cd concentration was found up to 665 μg g?1 in soils and 26.5 μg g?1 in vegetation. The heavy metal content of some soil samples was highly variable. Data show that Pb is easily absorbed by plant roots and translocated to foliage. In spite of the high heavy metal level, no signs of toxicity were apparent in vegetation.  相似文献   

7.
The effects of Cu(II) sulfate on sediment respiration were investigated in a 3-phase aquatic microcosm, containing a calcareous, southern Ontario stream sediment. In Cu2+ treated flask-microcosms, with the pH restored to 7.1, both aerobic and anaerobic CO2 evolution were unaffected by 5000 jig Cu g?1 sediment over a 40-day period at 15 °C. Oxygen consumption in sediment was initially unaffected by 5000 μg Cu g?1. However, after 35 to 40 days, a significant reduction of 28% was observed. The added Cu?2+ was removed from the water column and the sediment solution. In microcosms containing 5000 μg g?1 of total Cu, only 1.00 ± 0.76 μg g?1 was water soluble Cu, and the free cupric cation (Cu2+) concentration was below the detection limit of the specific ion electrode (less than 0.01 μg g?1). Maximum Cu retention (98.6%) was observed at 2800 μg Cu g?1, above which fractional retention decreased. In a calcareous, organic rich, sediment of pH 7.1, Cu+ was essentially unvailable to exert a toxic effect on respiration.  相似文献   

8.
A cloud point extraction (CPE) procedure has been developed for the determination of available cadmium (Cd) and lead (Pb) in soil by flame atomic absorption spectrometry. The proposed method was based on the CPE of a complex from ammonium pyrrolidine dithiocarbamate (APDC) and metal Cd and Pb using emulsifier octyl polyethylene glycol phenol ether (OP) as surfactant. Conditions that would affect the complex formation and separation were researched in detail, including extraction conditions as well as pH, amount of the chelating agent, concentration of the surfactant, equilibration temperature and time, and salt effect. Under the optimized conditions, both of the calibration graphs were linear in range of 0–1.0 μg mL?1 with detection limits of 0.29 ng mL?1 for Cd and 2.10 ng mL?1 for Pb. The relative standard deviation (RSD) for 11 replicate measurements at 0.10 μg mL?1 of Cd and Pb were 2.18% and 4.04%, respectively. The enhancement factors were 48.8 and 61.6 for Cd and Pb, respectively. The recoveries of Cd and Pb at the spiking level of 0.10 μg g?1 in soil samples were from 91.7% to 115% and from 91.0% to 115%, respectively. The proposed method has been applied to the determination of available Cd and Pb in soil.  相似文献   

9.
Bone fluoride concentration was measured in field voles (Microtus agrestis) trapped throughout a year at a moderately polluted site 1 km south of an Al reduction plant at Holyhead, Anglesey. Fluoride values ranged from 300 to 4800 μg g?1, with a mean of 2074 μg g?1 and increased with age as judged by dried eye-lens weight and body weight. At a heavily polluted site about 250 m from the pot-room of the reduction plant field voles had bone fluoride concentrations which ranged from 910 to 11000 μg g?1 with a mean of 7148 μg g?1. Wood mice (Apodemus sylvaticus) at this same location had a mean bone fluoride concentration of 8430 μg g?1 and ranged from 1800 to 17 200 μg g?1. The difference in mean bone fluoride concentration between these two species at this location was not significant (P > 0.1). A sample of field voles from presumed unpolluted sites in other parts of Britain had bone fluoride concentrations which ranged from 23 to 540 μg g?1 with a mean of 168 jig g?1. There was a high positive correlation (r > 0.97) between fluoride concentrations in different parts of field vole skeletons. There was no correlation between bone fluoride concentration in field voles and their femur diameters (r < 0.2).  相似文献   

10.
Barley (Hordeum vulgare L.) was grown on a sandy soil given different doses of cadmium carbonate (salt), copper carbonate (malachite), lead carbonate (cerussite), and zinc carbonate (smithsonite) in a pot experiment conducted in a greenhouse. The element compounds were added to the soil in amounts equivalent to the following levels of the metals: Cd 5, 10, 50 μq ?1; Cu and Pb 50, 100, 500 μg g?1; Zn 150, 300, 1500 μg g?1. Sequential extraction was used for partition these metals into five operationally-defined fractions: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter and residual. The residue was the most abundant fraction in the untreated soil for all the metals studied (43 to 61% of the total contents). The concentration of exchangeable Cd (0.2 μg g?1), Cu (0.01 μg g?1), Pb (0.1 μg g?1), and Zn (1.4 μg g?1) were relatively low in the untreated soil but increased markedly in the treated soils for Cd (up to 31 μg g?1) and Zn (up to 83 μg g?1), whereas only small changes were observed for Cu and Pb. The pot experiment showed a significant increase in the Cd and Zn contents of barley grown on the treated soils, but only small changes in Cu and Pb concentrations.  相似文献   

11.
Three months after neutralization concentrations of methylmercury (MeHg) were higher in the water of the limed than in the control basin of a small lake. After two years, the concentrations in the limed basin were somewhat lower than in the control (0.056–2.19 ng L?1 and 0.129–2.65 ng L?1, respectively). The highest concentrations were found in the anoxic hypolimnia. The total amount of MeHg in the water mass of the lake varied from 19 to 68 mg, showing a drop after spring and autumn overturns and a maximum during stratification periods. The total Hg concentrations of fish in L. Iso Valkjärvi varied from 0.06 to 0.14 μg g?1 (ww) in whitefish to 0.1 to 0.7 μg g?1 in perch and to 0.2 to 1.4 μg g?1 in pike. The total amount of MeHg bound in the fish of the lake was quite similar to that in the water column, 43 to 59 mg in 1990–1993, 33 to 47 mg of which was in the perch population.  相似文献   

12.
The effect of 50, 100, 150, and 400 μg sodium pentachlorophenate (Na-PCP) per gram soil was studied in nonsterile soil incubated under aerobic and anaerobic conditions, and in sterilized soil inoculated withAzotobacter sp. isolated from the soil. N2 fixation was determined by acetylene reduction. Pentachlorophenate at a concentration of 50 μg g?1 had an inhibitory effect in nonsterile soil incubated aerobically while strong inhibition of dinitrogen fixation in nonsterile soil occurred in the presence of 100 μg g?1 and above. The EC50 values for the inhibition of nitrogenase activity in nonsterile soil incubated aerobically and anaerobically and in sterilized soil inoculated withAzotobacter sp. suspensions were 49.8±1.4 μg Na-PCP g?1, 186.8±2.8 μg Na-PCP g?1, and 660.8±29.3 μg Na-PCP g?1, respectively.  相似文献   

13.
The aquatic vascular plant Eurasian watermilfoil (Myriophyllum spicatum L.) was investigated for its potential to take up Cd from nutrient-rich water in a short-term growth and harvest regime. Eurasian watermilfoil plants were grown in and harvested weekly from 0.10M Hoagland nutrient solutions containing concentrations of Cd from 0.04 to 7.63μg Cd mL?1. Dry weights of plants significantly decreas4ed when exposed to 7.63μg Cd mL?1. For both 0.04 and 1.03μg Cd mL?1 treatment the greatest concentration of Cd in plants occurred during the first two weeks. The greatest Cd concentration of Cd in plants for the 7.63μg Cd ML?1 treatment occurred during week one and decreased through week 2. Tissue P concentration in control plants increased over time but did not increase significantly over time when plants were exposed to 0.04 and 1.03μg Cd mL?1 levels. Tissue P concentration decreased over time when plants were exposed to 7.63μg Cd mL?1. Stem length, root dry weights, and root number significantly increased over time in control plants and in those exposed to the 0.04 and 1.03μg Cd mL?1 treatments. Plants treated with 7.63μg Cd mL?1 did not grow. These results suggest that Eurasian watermilfoil would be useful for absorbing Cd from nutrient-rich water when the solution concentration was in the range of 0.04 to 7.63μg Cd mL?1. However, in solutions having the highest concentration of Cd, the harvest regime would have to sustain plant vigor, avoid tissue Cd loss, and realize maximum uptake of Cd from solution.  相似文献   

14.
Elevated Hg levels in game fish from wilderness lakes in northern Minnesota led to the present study of sediment cores from two lakes to ascertain the source and history of Hg deposition. Natural background levels of Hg were found to range from 0.03 to 0.06 μg g?1, with cultural levels as high as 0.16 μg g?1. Reconstructed geochronologies reveal a dramatic two-fold increase in Hg flux, from 0.008 to 0.017 μg cm?2 yr?1, occuring after the year 1880, suggesting an anthropogenic influence. No industrial or geologic source of Hg is found in the study watersheds. The entire historical increase in Hg flux can be accounted for by atmospheric loading provided that 1/5 of all the Hg presently supplied to the watershed via precipitation is ultimately deposited in lake sediment. Hg levels in fish are not correlated with Hg levels in lake sediment, although there is a link to acid-sensitivity of lake water, amount of acid-neutralizing geologic material exposed in the watershed, and watershed area/lake volume ratio. Thermal stratification of lake water and a complexation-adsorption mechanism are proposed to account for variations in Hg levels observed in sediment collected from different sites.  相似文献   

15.
The sulphate ion concentrations in rainwater samples, collected in a central area of Rome (Italy), were measured by an indirect atomic absorption spectrometric method. The reproducibility of sample preparations and analysis were found to have a max SD: ± 20%. The month to month variation in SO f4 p2? concentration varied from 3 to 27 μg mL?1.  相似文献   

16.
The accumulation of Be and Ge by selected macrohydrophytes in environments polluted by industrial dust and waste products was shown to be higher than the average concentrations in unpolluted water. The Ge content of macrohydrophytes in polluted environments ranges from 7.1 to 220.4 μg g?1 and the Be content from 0.7 to 136.6 μg g?1. We have at the same time shown the relationships between Be and Ge in water and plants. The accumulation of Be and Ge in plants is conditioned by the amount of N and K in water, hydrosol and in the plants themselves. Our experiments show growth disturbances in macrohydrophytes containing high concentration of Be and Ge.  相似文献   

17.
Chromium occurs naturally at trace levels in most soils and water, but disposal of industrial waste and sewage sludge containing chromium compounds has created a number of contaminated sites, which could pose a major environmental threat. This study was conducted to enumerate and isolate chromium-resistant microorganisms from sediments of evaporation ponds of a metal processing plant and determine their tolerance to other metals, metalloids and antibiotics. Enumeration of the microbiota of Cr-contaminated sediments and a clean background sample was conducted by means of the dilution-plate count method using media spiked with Cr(VI) at concentrations ranging from 10 to 1000 mg L?1. Twenty Cr(VI) tolerant bacterial isolates were selected and their resistance to other metals and metalloids, and to antibiotics was assessed using a plate diffusion technique. The number of colony-forming units (cfu) of the contaminated sediments declined with increasing concentrations from 10 to 100 mg L?1 Cr(VI), and more severely from 100 to 1000 mg L?1 Cr(VI). The background sample behaved similarly to 100 mg L?1 Cr(VI), but the cfu declined more rapidly thereafter, and no cfu were observed at 1000 mg L?1 Cr(VI). Metals and metalloids that inhibited growth (from the most to least inhibitory) were: Hg > Cd > Ag > Mo = As(III) at 50 μg mL?1. All 20 isolates were resistant to Co, Cu, Fe, Ni, Se(IV), Se(VI), Zn, Sn, As(V), Te and Sb at 50 μg mL?1 and Pb at 100 μg mL?1. Eighty-five percent of the isolates had multiple antibiotic resistance. In general, the more metal-tolerant bacteria were among the more resistant to antibiotics. It appears that the Cr-contaminated sediments may have enriched for bacterial strains with increased Cr(VI) tolerance.  相似文献   

18.
Forest floor and mineral soil samples were collected from subalpine spruce-fir forests at 1000 m above mean sea level on 19 mountains in the northeastern United States to assess patterns in trace metal concentrations, acidity, and organic matter content. The regional average concentrations of Pb, Cu, and Zn in the forest floor were 72.3 (2.9 s.e.) μg g?1, 8.5 (0.7) μg g?1, and 46.9 (2.0) μg g?1, respectively. The regional average concentrations of Pb, Cu, and Zn in the mineral soil were 13.4 (0.8) μg g?1, and 18.2 (1.2) μg g?1, respectively. The regional average pH values of the forest floor and mineral soil were 3.99 (0.03), and 4.35 (0.03), respectively. The Green Mountains had the highest concentrations of Pb (105.7 μg g?1), and Cu (22.7 μg g?1), in the forest floor. They also had the highest concentrations of Cu (18.0 μg g?1), in the mineral soil. Site aspect did not significantly influence any of the values. Concentrations of Pb were lower than concentrations reported earlier in this decade at similar sites while concentrations of Cu and Zn remained the same. We believe that these lower Pb concentrations reflect real changes in forest Pb levels that have occurred in recent years.  相似文献   

19.
The earthworms Allolobophora catiginosa and Lumbricus rubellus were used to study the toxicity of 2,3,7,8-TCDD (dioxin) for earthworms. The earthworms were exposed to soil containing concentrations ranging from 0.05 to 5.0 μgg?1. No worms were killed or showed any other observable toxicological effects when exposed to concentrations up to 5 μg g?1 for 85 days in soil. The lethal threshold concentration for TCDD to earthworms falls between 5 and 10 μg g?1 in this study. In soils containing 0.05 μg g?1 earthworms accumulated TCDD up to 5 times the original soil concentration within 7 days. Worms were also exposed to TCDD on filter paper to study the behaviour of earthworms and the uptake of TCDD after surface contact. The earthworms did not avoid TCDD in their environment, indicating an indifference to it. No active penetration of TCDD into the body occurred where earthworms were exposed to surface concentrations. No indication was found of possible biological breakdown of TCDD on passing through the earthworm gut, although the search for metabolites was limited to the mono-, bi- and trichlorinated dioxins. There was a steady decrease (a T12-value of 80–400 days) in the amount of TCDD recovered from worm-worked soil compared to soil without worms.  相似文献   

20.
The effect of adding cobalt, as 60Co, to the food source of the earthworm Eisenia foetida was studied. Cobalt was retained with a half-life of 387 ± 43 (SD) days in the worm. After 172 days more cobalt was concentrated in the gut than the body wall. 60Co was not transmitted from adults to cocoons. Prolonged studies involving the addition of CoCl2 (0, 8.2, 16.5 and 82.5 μg Co g?1) to a food source low in Co indicated that total Co concentrations of 17.6 and 25.9 μg g?1 resulted in significantly increased maximum weights compared to the control worms which were exposed to 9.4 μg Co g?1. The highest Co addition (82.5 μg g?1, total 91.9 μg g?1) caused no increase in maximum weight over controls, but resulted in a statistically significant lag in early growth compared to that of all other groups. Significantly more cocoons were produced by worms fed 17.6 or 25.9 μg Co g?1 compared with those fed 9.4 or 91.9 μg Co?1 Co.  相似文献   

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