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1.
The distribution of different homological groups of polychlorinated biphenyls (PCBs) in the urbanozem profile of the arboretum in the Botanical Garden of Moscow State University has been considered. The levels of their content, the composition of a congener spectrum, potential sources, and the ecotoxicological impact of soil pollution are assessed. The maximal concentrations of di-, tri-, and tetrachlorbiphenyls are observed in the technogenic layer of soil at a depth of 20–40 cm (0.30, 0.44, and 24.25 μg/kg, respectively), and penta- and hexachlorbiphenyls in the surface humus layer (42.33 and 17.89 μg/kg, respectively). The content of hepta- and oñtachlorbiphenyls varies insignificantly with increasing the depth (0.67–1.25 and 0.15–0.41 μg/kg, respectively). Penta- and hexachlorbiphenyls contribute most to the spectrum of PCBs in urbanozem.  相似文献   

2.
Rain water samples were regularly collected from three sites, namely, Netaji Nagar, Moti Nagar and Town Hall within the Delhi city area from July, 1980 to June, 1982. The pesticide residues were adsorbed on polyurethane foam coated with 0.5 % DC-200 and subsequently extracted and analyzed for DDT, HCH and their metabolites/isomers. The concentration of total DDT ranged from 0.22 to 108 μg L?1 with a mean value of 12.5 μg L?1. The samples of rain water contained varying levels of 4,4-DDT, 2,4-DDT, 4,4-DDE, and 4,4-DDD. The 4,4-DDT, 4,4-DDE and 2,4-DDT were the main components of total DDT. The range of HCH residues in rain water was from 0.08 to 43 μg L?1 with a mean of 5.3 μg L?1. The residues of HCH consisted mainly of α- and γ-isomers with traces of β and δ-isomers. The α- and γ-isomers accounted for 76 and 24% of total HCH, respectively. The concentrations of DDT and HCH in rain water were generally less than 10 μg L?1 and exceeded 10 in only 4 and 3 cases, respectively. The residues of these insecticides were generally higher during October to December. Residues of DDT were higher at Moti Nagar which is near a DDT factory. Residues of HCH were maximum at Town Hall, a commercial area of the city.  相似文献   

3.
The spatial and temporal distribution of persistent chlororganic compounds in the form of insecticide residues—DDT, DDE, DDD, HCH and industrial pollutants—polychlorobiphenyls (PCBs) has been monitored in various components of irrigated agrolandscapes (soil, water, bottom sediments) in the Moscow region, the Kuban lowplain of the Krasnodar region (Russia) and in the Samarkand oasis (Uzbekistan) for the period 1989–1990. The widespread occurence of PCB compounds requires action for their hygienic control and monitoring. The main chlororganic pollutant found were DDT residues and their content in soils and bottom sediments in all regions under study exceeded in many cases the existing baselines (100 µg/kg). Special attention has been given to the ratios between various metabolites and isomers of chlororganic insecticides as well as between various homologs of PCBs among which tetrachlorobiphenyls were predominant in soils, bottom sediments and surface waters.  相似文献   

4.
The content and distribution pattern of dichlorodiphenyltrichloroethane (DDT) and its metabolites (DDE and DDD) in the surface layers of soils in Moscow are studied. The residual content of these substances in the soils varies within 2.22–1440 µg/kg (at a mean value of 158.9 ± 314.1 µg/kg and median 42.53 µg/kg). The correlation between the contents of DDT and its metabolites and DDD and organic matter is revealed. The highest contents of the pollutants are seen in the residential–transport and industrial zones of Moscow, while their lowest contents are revealed in the soils of the yards of preschool facilities and schools. With respect to the residual contents of the pesticide, most of the soils of Moscow can be considered uncontaminated (80.0%) and acceptably contaminated (7.5%).  相似文献   

5.
A procedure that combines acetone-hexane extraction and cleanup by treatment with concentrated sulfuric acid is described for determining DDT and 1,2,3,4,5,6-hexachlorocyclohexane (HCH) residues in milk. Recoveries from samples fortified with 0.004-0.008 ppm of different HCH isomers and 0.01-0.02 ppm DDT and its metabolites ranged from 83.4 to 99.8%. The proposed method is simple and rapid, and does not require the use of costly adsorbents.  相似文献   

6.
在室温条件下,采用盆栽试验方法研究了小麦和玉米作物根系对自然污染土壤中不同水平老化HCH、DDT的富集作用及其影响机制。通过连续提取,将根系富集的有机氯农药分为弱吸着、强吸着和吸收3种不同形态。结果表明,作物对老化HCH、DDT的富集存在选择性。在60d的试验周期内,玉米根系富集的HCH、DDT中55.4%~62.2%为根表强吸着,23.3%~36.9%为根内吸收;而小麦根系中HCH,DDT的73.8%-76.9%被根表强吸着,仅15.4%-20.5%可以进入根系组织内部。不同形态组分中异构体及代谢物的组成比例差异化明显,其中吸收态以β-HCH为主,强吸着态以P,p'-DDT、p,p'-DDE和P,p'-DDD为主。随着土壤污染水平的增加,小麦和玉米根系对HCH、DDT的富集总浓度增加,而生物蓄积系数逆浓度梯度增加,小麦根系的富集能力强于玉米。在控制污染水平的条件下,作物根系对土壤老化HCH、DDT的富集量与其根系比表面积大小和总脂含量极显著正相关,而向根系深层组织运移的过程主要受总脂含量控制。  相似文献   

7.
对长江三角洲地区某废旧电容器拆解场地周边农田基本保护区表层水稻土中含氯有机化合物的组成及含量进行初步研究。结果表明,供试土壤中20种PCBs总含量在84.19~377.4μg kg-1之间,平均含量为204.8μg kg-1,其中二氯、三氯、四氯代同系物总和占总PCBs的73.7%~96.2%,存在着PCBs的外源输入。HCH的总含量为10.61~33.11μg kg-1,DDT总含量为11.36~33.28μg kg-1,残留水平较低,但β-HCH、γ-HCH、∑HCH和∑DDT的平均含量均高于荷兰土壤标准的目标值。此外,DDT与土壤有机碳呈显著负相关,而其他含氯有机化合物的含量并未呈现出与土壤有机碳的相关性。  相似文献   

8.
Suresh Babu  G.  Farooq  M.  Ray  R. S.  Joshi  P. C.  Viswanathan  P. N.  Hans  R. K. 《Water, air, and soil pollution》2003,144(1-4):149-157
Organochlorine pesticides were used earlier for agricultureproduction. Their residues may still be present in soil and mayaccumulate in food crops, posing potential health problems to consumers. DDT, HCH, their isomers and metabolites were analyzedin samples of soil and rice plants collected from ten differentvillages of a well-known Basmati rice growing area in Dehradun.Residues of both pesticides were found in all samples ofsoil and different parts of rice plants except for a few grainsamples. Maximum residue was observed in husk and minimum ingrains. The average concentration of DDT in soil ranged from0.013 to 0.238 ppm. p,p′-DDE was the major metabolite (>63%). Theaverage concentration of DDT in rice grain varied from 0.002 to 0.040 ppm. o,p′-DDT was the main isomer (>93%). Theaverage concentration of HCH in soil ranged from 0.122 to 0.638 ppm. β-HCH was the predominant (43%) isomerfollowed by α-HCH (21%). The average HCH concentrationin rice grain ranged between 0.013 and 0.113 ppm. All four isomers were present in grains. The levels of DDT and CHCin grains were similar in magnitude as those from differentIndian states, but well below the maximum residue limit of 0.1 ppm for DDT and 0.05 ppm for HCH prescribed by the Government ofIndia and WHO/FAO. As such, the pesticide residue levels in thisexport commodity are not of hazardous nature.  相似文献   

9.
采样测定了巢湖东半湖4个样点的表层沉积物中有机氯农药(OCPs)的含量。结果表明,11种有机氯农药在样品中被检出,总含量为8.26~31.73 ng.g^-1;OCPs在沉积物中的垂直分布从上往下大体呈递减趋势;且OCPs的最高含量都出现在上层沉积物中,说明巢湖东半湖沉积物中有机氯农药主要集中在0-3 cm的表层。根据分析,DDTs来自于早期残留或者施用农药后的长期风化残留。沉积物风险评估表明,巢湖东半湖表层沉积物中的有机氯农药存在一定的生态风险。  相似文献   

10.
In the last decades, the chromium clarke in the world’s soils has been revised and reduced; at present, it is equal to 70 mg/kg. No maximal permissible concentration is accepted for the total chromium content in the soils of Russia; it appears reasonable to use the Western European and North American standards in Russia and to take the average value of the maximal permissible concentration equal to 200 mg Cr/kg. Chromium toxicity depends on its oxidizing status. The hazardous effect decreases with the reduction of Cr(VI) to Cr(III). There are various chemical reducers of Cr(VI), including sulfides, dissolved organic substance, aqueous Fe(II) and minerals enriched in Fe(II), and Fe(0). As-containing ore tailings represent a powerful source of technogenic arsenic. Significant environment contamination with natural As is registered in a number of Asian countries. The maximal permissible concentration of total arsenic is equal to 2 mg/kg in Russian soils; it is probably underestimated, because it is lower than the As clarke in soil (5 mg/kg). The approximately permissible concentration (APC) values for As look more reasonable. Arsenic toxicity depends on its oxidation degree: As(III) is 2–3 times more toxic than As(V).  相似文献   

11.
氯代持久性有机污染物的农田土壤污染呈现污染浓度低、面积大、新源污染不断输入的特点。农田土壤本身微生物种类丰富,对氯代有机污染物具有较大的降解潜力和未知性。本试验以典型高氯代和低氯代持久性有机污染物——六氯苯(HCB)和滴滴涕(DDT)为研究对象,结合~(14)C同位素示踪技术,研究HCB和DDT在热带水稻土和甘蔗地土壤的矿化现象,同时监测HCB和DDT在两种土壤中的挥发、降解产物以及结合残留。结果表明,经84 d好氧培养,HCB和DDT在两种土壤中的矿化量分别仅为0.14%和3%,低氯代有机污染物DDT的矿化速率显著高于高氯代有机污染物HCB。然而,两种土壤对HCB或DDT的矿化没有显著性差异。HCB或DDT在水稻土中的挥发量略微高于甘蔗地土壤,两种土壤中HCB和DDT的挥发量在0.1%~0.6%之间,表明挥发不是其主要的环境过程。在DDT污染水稻土和甘蔗地土壤中添加1.25%的堆肥增加了DDT在土壤中的矿化与结合残留,减少了DDT的挥发。本研究结果表明土壤在好氧条件下对氯代持久性有机污染物的自然消解能力非常弱,而有机肥的使用有助于土壤中持久性氯代有机污染物的矿化消除。  相似文献   

12.
Assessment of pesticide residues in honey samples from portugal and Spain   总被引:1,自引:0,他引:1  
Fifty samples of honey collected from local markets of Portugal and Spain during year 2002 were analyzed for 42 organochlorine, carbamate, and organophosphorus pesticide residues. An analytical procedure based on solid-phase extraction with octadecyl sorbent followed by gas chromatography-mass spectrometry (GC-MS), for organochlorines, and by liquid chromatography-atmospheric pressure chemical ionization-mass spectrometry (LC-APCI-MS), for organophosphorus and carbamates, has been developed. Recoveries of spiked samples ranged from 73 to 98%, except for dimethoate (40%), with relative standard deviations from 3 to16% in terms of repeatability, and from 6 to 19% in terms of reproducibility. Limits of quantification were from 0.003 to 0.1 mg kg(-)(1). Most of the pesticides found in honey were organochlorines. Among them, gamma-HCH was the most frequently detected in 50% of the samples, followed by HCB in 32% of the samples and the other isomers of HCH (alpha-HCH and beta-HCH) in 28 and 26% of the samples, respectively. Residues of DDT and their metabolites were detected in 20% of the samples. Of the studied carbamates, both methiocarb and carbofuran were detected in 10% of the samples, pirimicarb in 4% and carbaryl in 2%. The only organophosphorus pesticides found were heptenophos in 16%, methidathion in 4%, and parathion methyl in 2% of honey samples. Results indicate that Portuguese honeys were more contaminated than Spanish ones. However, honey consumers of both countries should not be concerned about the amounts of pesticide residues found in honeys available on the market.  相似文献   

13.
Villa  S.  Finizio  A.  Diaz Diaz  R.  Vighi  M. 《Water, air, and soil pollution》2003,146(1-4):335-349
The distribution of persistent organochlorine pesticides (HCB, HCH, DDT and its metabolites) was studied by analyzing pine needles in the oceanic island of Tenerife (Canary Islands, Spain). Tenerife is a subtropical oceanic island, characterized by the presence of a high mountain (Pico de Teide, 3,718 m a.s.l.) and by a peculiar climatic condition. The southern side is warm and sometimes during the year influenced by dry winds coming from Africa, while the northern side is cool and wet, with an almost persistent cloudiness (called `mar de nubes'), due to winds coming from the northern Atlantic. Furthermore a developed agricultural area is present at sea level. Pine needle samples were collected on both sides of the island, from the sea level up to the upper level of pine distribution (2,100 m a.s.l.). The distribution patterns of organochlorine pesticides seem to be affected mainly by local emissions. Up to the considered altitude layer, the influence of global circulation of persistent organic pollutants seems to play a negligible role. The behavior of chemicals is consistent with their physical-chemical properties, with some influence due to climatic conditions.  相似文献   

14.
李勋光 《土壤学报》1993,30(1):88-93
本研究采用干筛法和重力干沉降法对5种表土进行土粒粒径分离,研究在北京地区的风沙季节,地表土的DDT、BHC量与土粒粒径、有机质量之间的关系。结果表明,土壤残留DDT、BHC农药主要分布在土粒粒径为<0.25mm组分中,其中容易被气流浮动的<0.05mm粒径组分的DDT和BHC量,分别占原来表土量的41-89%和30-81%。在一定粒径范围,粒径越小,DDT、BHC含量越高,且与有机质含量之间呈极显著正相关(P<0.01)。同时,土粒中DDT、BHC及其某些代谢产物和异构体的比例却随土粒粒径的不同而变化。  相似文献   

15.
渭北旱塬管理措施对冬小麦地土壤剖面物理性状的影响   总被引:1,自引:1,他引:0  
【目的】研究黄土高原旱作农业区不同施肥覆盖措施对冬小麦地0—40 cm土壤剖面物理性质的影响,可为保持良好的土壤物理性状,探求适合渭北旱塬可持续的田间管理措施提供参考。【方法】基于设在渭北旱塬15年的田间定位试验,选取NP (N 150 kg/hm^2+P 75 kg/hm^2)、NPK (NP+K 30 kg/hm^2)、NPB (NP+biochar 14.0t/hm^2)、NPFFT (NP配合地膜夏闲期覆盖)、NPFGT (NP配合地膜生育期覆盖)和NPFWT (NP配合地膜全年覆盖)共6个处理。于2017年冬小麦收获期采集剖面土样,对0—10 cm、10—20 cm、20—30 cm和30—40 cm土层土壤含水量、土壤容重、饱和导水率和水稳定性团聚体等相关土壤物理性质进行测定与分析。【结果】与NP相比,NPK处理降低了收获期0—20 cm土壤容重,增加了耕层土壤总孔隙度和0—40 cm土层> 2 mm水稳定性团聚体含量,0—10 cm土层> 2 mm水稳定性团聚体含量显著提高了1.3倍(P <0.05);NPB处理,收获期耕层土壤容重降低,土壤总孔隙度增加,表层土壤饱和导水率显著降低27.9%,剖面土壤含水量和> 2 mm水稳定性团聚体含量均增加,且表层> 2 mm水稳定性团聚体含量显著提高了1.0倍;NPFFT处理收获期剖面土壤含水量降低,耕层土壤容重增加,总孔隙度降低;NPFGT处理收获期耕层土壤容重和剖面土壤含水量均增加,耕层总孔隙度降低,剖面土壤饱和导水率降低,尤其表层显著降低60.2%;NPFWT处理收获期耕层土壤容重增加,总孔隙度降低,表层土壤饱和导水率降低,但10—40 cm土壤饱和导水率平均提高57.5%,剖面土壤含水量、> 2 mm水稳定性团聚体含量、平均重量直径和几何平均直径均增加。受当地传统耕作深度的影响,不同施肥覆盖措施对土壤容重、饱和导水率和孔隙度的影响主要集中在0—20 cm土层,对20—40 cm土层影响较小。【结论】在氮磷肥配施的基础上,增施钾肥、生物炭和地膜全年覆盖均有利于改善试验农田土壤物理性质,但从经济投入和对土壤物理性状改良程度方面考虑,增施钾肥和地膜全年覆盖这两种处理是保持渭北旱塬良好土壤剖面物理性质的有效措施。  相似文献   

16.
The results of long-term studies of the contents of bulk forms of metals (Cu, Zn, Fe, Ni, Pb, Mn, Co, and Cd) and their mobile compounds in soils of background and human-disturbed areas within the Krasnoural’sk–Sibai–Gai copper–zinc and Baimak–Buribai mixed copper mineralization zones in the Bashkir Transural region are discussed. It is shown that soils of the region are characterized by abnormally high natural total contents of heavy metals (HMs) typomorphic for ore mineralization: Cu, Zn, and Fe for the Sibai province and Cu, Zn, and Ni for the Baimak province. In the case of a shallow depth of the ores, the concentrations of HMs in the soils are close to or higher than the tentative permissible concentration values. The concentrations of mobile HM compounds in soils of background areas and their percentage in the total HM content strongly vary from year to year in dependence on weather conditions, position in the soil catenas, species composition of vegetation, and distance from the source of technogenic contamination. The high natural variability in the content of mobile HM compounds in soils complicates the reliable determination of the regional geochemical background and necessitates annual estimation of background parameters for the purposes of the ecological monitoring of soils. The bulk content of Cu and Zn content in soils near mining enterprises exceeds the regional geochemical background values by 2–12 times and the tentative permissible concentrations of these metals by 2–4 times. Anthropogenic contamination results in a sharp rise in the content of mobile HM compounds in soils. Their highest concentrations exceed the maximum permissible concentrations by 26 times for Cu, 18 times for Zn, and 2 times for Pb. Soil contamination in the impact zone of mining enterprises is extremely dangerous or dangerous. However, because of the high temporal variability in the migration and accumulation of HMs in the soils, the recent decline in the ore mining activities, and the construction of purification facilities, no definite temporal trends in the contents of HMs in the soils have been found in the studied region for the period from 1998 to 2015.  相似文献   

17.
Humification conditions and humus status parameters in arboretum soils of the Moscow State University botanical garden on the Vorob’evy Hills have been studied. Although microbiological activity is reduced, the warm and mild climate in the city, the eutrophication of soils (due to atmospheric fallouts and dissolution of construction waste inclusions), the retention of plant waste on the soil surface, and the presence of abundant primary destructors (mesofauna) have resulted in the formation of organic matter with specific characteristics. During the 60 years that have elapsed since the arboretum establishment, soils with a high content (up to 10–14%) of humate humus (CHA/CFA > 1) characterized by a higher degree of humification than in the control soils under herbaceous vegetation have been developed in the area. Large reserves of organic carbon have been noted not only in the upper 30-cm-thick soil layer, but also in the 1-m-thick layer due to organic matter of buried and technogenic horizons.  相似文献   

18.
2004年5月和6月采集了安徽、江苏、湖南、湖北省5个茶园的38个土壤表层样品,利用ASE萃取技术,使用GC/MS方法测定了样品中的六氯苯、氯丹、总滴滴涕(DDE、DDD和DDT)、艾氏剂、狄氏剂、异狄氏剂、七氯和灭蚁灵等八种有机氯杀虫剂。5个茶园的六氯苯、总滴滴涕的检出率都为97.4%,是茶园土壤中普遍存在的两类持久性有机污染物(POPs)。艾氏剂、狄氏剂、异狄氏剂、七氯等未检出。总有机氯杀虫剂含量平均为17.4!g kg-1,总滴滴涕占总有机氯杀虫剂含量的97.9%,是茶园土壤中有机氯杀虫剂残留的主要成分。六氯苯的残留量很低,没有对茶园土壤质量造成危害。  相似文献   

19.
The concentration of dichlorodiphenyltrichloroethane (DDT) was determined in a sandy soil of specially Protected Natural Area Osinskaya Lesnaya Dacha (Perm region) 45 years after the last application of the insecticide in this area. The concentration of DDT in the soil exceeded the maximum permissible concentration by 250 times and reached 25.05 mg/kg of soil. Under the conditions of model experiment, efficient decontamination of the soil was recorded in the system with the introduced strain Rhodococcus wratislaviensis Ch628; the DDT concentration decreased by 99.7% and equaled 0.07 mg/kg. The process of DDT degradation proceeded slower in the model soil system with autochthonous microbial complex. In this case, 58.2% DDT degraded in 70 days, and the final concentration was 10.47 mg/kg. The soil lost its toxicity for animal and plant test objects by the end of the experiment only in the model system containing the R. wratislaviensis Ch628 strain.  相似文献   

20.
Regular monitoring of air at three different sites, namely, Netaji Nagar, Moti Nagar and Town Hall in the metropolitan city of Delhi, India from June, 1980 to May, 1982 revealed varying levels of residues of DDT and HCH. The concentration of total DDT residues varied from 4 to 232 ng m?3 with an average of 60 ng m?3. Total HCH ranged from 0 to 21797 ng m?3 with an average of 438 ng m?3. Comparatively higher levels of total DDT (73 ng M?3) were detected at Moti Nagar, the site near a DDT factory. The total HCH was highest at Town Hall (931 ng m?3). Normally, higher quantities of the residues of DDT and HCH were detected during October to December. The insecticide residues consisted mainly of p, p′-DDT, p, p′-DDE, o, p′-DDT and p, p′-DDD, α- and γ-HCH. Only p, p′-DDT and p, p′-DDE were detected in all the samples and accounted for the bulk of total DDT. The HCH residues were mainly due to the α-isomer. Generally the concentration of HCH was higher than DDT in the air samples collected during the survey.  相似文献   

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