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21.
F. Rincón-León G. Zurera-Cosano R. Moreno-Rojas M. Amaro-López 《Environmental monitoring and assessment》1993,27(3):193-200
The importance of eating habits and the number of fish sampled in the estimation of mercury environmental contamination through biological indicators was studied. The species used were one with piscivorous habits (Anguilla anguilla) and another with omnivorous habits (Ciprinus carpio). From one original sample for each species, randomized samples were generated using the subroutine GGSRS from the mathematics library IMSL, and later the statistical significance of Pearson's correlation coefficient for the relationship between fish weight and mercury concentrations in muscle was obtained for each random sample. The results show that the use of omnivorous species such as Ciprinus carpio as a biological indicator of contamination enables us to carry out estimations with a greater degree of confidence than when piscivorous species such as Anguilla anguilla are used. 相似文献
22.
Jürgen Breitung Dirk Bruns-Nagel Eberhard von Löw Klaus Steinbach Lothar Kaminski Rainer Haas Diethard Gemsa 《Environmental Sciences Europe》1995,7(4):195-200
Within the limits of a feasability study abouton-site bioremediation methods for TNT-contaminated soils, composting was chosen as a very promising and cheap method. This method was critically compared with those described in the literature and was primarily rated under ecotoxicological aspects. The investigated location is the former munition plant «Tanne» in the aerea of Clausthal-Zellerfeld in Lower Saxony, Germany. To estimate the autochtonic microflora, we assessed the number of aerobic heterotrophic bacteria and determined their respiration activity in soils. In addition, we isolated bacteria and examined their capacity to metabolize TNTin vitro. Both the amount of autochtonic microrganisms (4.7×108 to 1.2×1010 colony forming units (cfu)/kg dryweight) as well as their respiration activity did not correlate with the concentrations of nitrotoluenes in the soils. With high contaminated soil (20 g TNT/kg dry weight) we carried out a small compost in the range of 10 liters. During 28 days of composting TNT-concentration decrease over 90% and only minor amounts of monoaminodinitrotoluenes were generated. However, an acidic pretreatment of the compost material at the end of the reaction showed that TNT could be partially resolved under these extreme conditions and that an ecotoxicological risk may still exist. Possible changes in the realization of the composting process in order to make sure that the contaminants are savely bound to the humin matrix are discussed. 相似文献
23.
Processes involved in uptake and release of nitrogen dioxide from soil and building stones into the atmosphere 总被引:1,自引:0,他引:1
Atmospheric NO2 was taken up by samples of various soils and building stones. The NO2 uptake rate constants were highest in soil samples taken during the summer months. However, the NO2 uptake rate constants of the soils and building stones were not significantly correlated with any of the following variables: moisture, pH, ammonium, nitrite, or nitrate. NO2 uptake by soil and stone was not abolished by autoclaving indicating a chemical uptake process. NO2 uptake by acidic and air-dry soils and stones resulted in nearly stoichiometric reduction of NO2 to NO. This reduction was enhanced by the addition of ferrous iron and was further enhanced by incubation under 1 ppmv SO2. The results suggest that NO2 reduction may be coupled to oxidation of ferrous to ferric iron which may be reduced again by atmospheric SO2 thus regenerating the ferrous iron content of the soil or stone. Conversion of NO2 to NO was not observed in neutral or/and moist soils and stones. NO2 was also taken up by purified and sterilized quartz sand moistend with water. This uptake was enhanced by addition of humic material but not by addition of bacteria which both had been extracted from genuine soil. Under most conditions, only uptake but no release of NO2 was observed. However, NO2 was released in air-dry soils that were heated to 45–65°C, or in ammonium-fertilized soil or stone that was drying up at room temperature. Under the latter conditions mimicking field practice, the NO2 release reached rates that were similar to the NO release rates. 相似文献
24.
D Heinevetter H J Lewerenz R Plass R Macholz 《Journal of environmental science and health. Part. B》1985,20(5):539-558
In vitro investigations of the influence of lindane and its metabolites were performed on microsomal and mitochondrial ATPases from liver, kidney and brain of rat and mouse. The microsomal Na+-K+-ATPases in rat liver were inhibited by the tested substances. An increase of activity was observed only with 2.5 X 10(-5) M gamma-HCH. Effects on the microsomal Na+-K+-ATPase from kidney and brain of rat were also indicated. The mitochondrial enzyme in rat liver was stimulated by all the compounds tested at concentrations of 10(-4) M - 10(-2) M. The effects on mitochondrial enzymes from kidney and brain varied in dependence on the tested substances. In the microsomes and mitochondria of mouse an influence on the Na+-K+-ATPases similar to the effects on the preparations from organs of rat was evident. 相似文献
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Mary C. Phelan R. Curtis Rogers Ron C. Michaelis C. Lynn Moore Will Blackburn 《黑龙江环境通报》2001,21(6):457-460
Mosaicism for trisomy 13 and triploidy was detected by amniocentesis performed at 18 weeks' gestation because of fetal anomalies. Pregnancy continued and a live-born male was delivered vaginally at 37 weeks. The infant had features common to both trisomy 13 and triploidy: intrauterine growth retardation (IUGR), small abnormal ears, cleft palate, and a small jaw. In addition, he had complete cutaneous syndactyly of fingers 3 and 4 and partial syndactyly of the toes, as seen in triploidy. Mixoploidy for trisomy 13 and triploidy was confirmed postnatally in blood, skin, and placenta. Examination of chromosome heteromorphisms and DNA markers suggested the presence of two maternal contributions in the triploid cell line. In addition, the extra chromosome 13 in the trisomic cell line was derived from the mother. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
29.
全球粮食生产的预测问题 总被引:1,自引:0,他引:1
Bo R.Doos 《Ambio-人类环境杂志》2002,31(5):417-424
本文讨论了全球粮食生产体系能力预测模型的研发问题,文章特别对影响粮食生产的各种因素进行了鉴定和分析,并且对它们的相对影响和可预测性进行了估计。 相似文献
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