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1.
Soil samples were taken from residential gardens, grasslands and forests at 22 locations in Marsberg, North Rhine-Westphalia, and analyzed for PCDD/F. Sampling was concentrated on the vicinity of a former copper smelter where copper waste material (calledKieselrot) was deposited and emissions from former stacks contaminated a large land area. Maximum PCDD/F-concentrations were 407 ng TE GBA/kg dm in garden soil (0–30 cm depth), 98 ng TE BGA/kg dm in agricultural grassland (0–10 cm depth), 227 ng TE BGA/kg dm in wasteland, and up to 8073 ng TE BGA/kg dm in forest soils. PCDD/F-levels in soil decreased with increasing distance from the former sources providing a large historic emission problem, apart from the still existing kieselrot waste site. Ash residues from former flue gas duct showed up to 2,4 mg TE BGA/kg dm. PCDD/F-concentrations in vegetable samples from highly contaminated garden soils and grass from agricultural grassland were found to be relatively low in relation to soil values. PCDD/F-levels in salad showed a mean of 2,2 ng TE BGA/kg dm while grass concentrations were <6 ng TE BGA/kg dm. Thus, no correlation was found between soil and vegetation values with the exception for carrot roots where obviously a small transfer of PCDD/F between the two media took place. PCDD/F-content in grass taken over the vegetation period showed a tendency to increase toward the end of the growing season, which is probably related to changes in the dry matter yield over the season. No correlation was found in general between soil, grass and milk PCDD/F contents when all samples were taken from the same grassland. PCDD/F-concentrations in milk ranged between 0,6 and 1,1 pg TE BGA/g milkfat and were thus in the same range as consumer milk in the Federal Republic of Germany. PCDD/F in needles from conifers showed a clear relationship with respect to distance from the former waste site. The relatively high levels in conifer needles [36 ng TE BGA/kg dm] were obviously due to sporting activities (i.e. motocross racing where contaminated material was resuspended and deposited on surrounding trees).  相似文献   

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This study was designed to assess the degree of exposure to PCDD/F in 56 selected persons living in the vicinity of a former copper smelter located in Marsberg, Germany. The copper smelter was in operation until 1945. In 1991, high levels of PCDD/F were found particularly in materials from the slag dumps (10 000 – 100 000 ng TE/kg). The levels of PCDD/F in blood fat were used as parameters for individual PCDD/F exposure. Since only limited reference data for PCDD/F in human blood were available, blood samples of a reference group were analyzed in the same way. The criteria were collected from a group matched for sex, age (±3 years) and body mass. The median NATO/CCMS-Toxicity equivalency values (NATO/CCMS-TE-values) of the Marsberg group (43,2 pg NATO/CCMS-TE/g blood fat) and the reference group (43,0 pg NATO/CCMS-TE/g blood fat) were similar, whereas the arithmetic mean of the Marsberg group (52,7 pg NATO/CCMS-TE/g blood fat) was higher than that of the reference group (44,4 pg NATO/CCMS-TE/g blood fat). The frequency distribution of the individual TE-values of the Marsberg group was slightly shifted toward higher values. The individuals of the Marsberg group had significantly higher levels of PentaCDF, HexaCDF and HeptaCDF on average than the individuals of the reference group. On the basis of TE-values, the majority of the individuals from Marsberg did not have an increased body burden of PCDD/F. However, some individuals could be identified with TE-values exceeding background levels ranging up to 231 pg NATO/CCMS-TE/g blood fat. Although it must be assumed that the unusual congener pattern found in many of the test subjects is a result of ingestion of contaminated slag material or soil, the findings of this study could not verify this fact.  相似文献   

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Distillation residues of dry cleaning machines contain small quantities of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/F), independent of the type of solvent employed. PCDD/F were not only detectable in distillation residues using perchloroethylene as dry cleaning solvent, but also similar quantities and congeneric patterns of PCDD/F were found in residues from machines operated with stoddart solvent or CFC 113. Current results suggest that PCDD/F occurrence is linked to the dirt adhering to the textiles. Dirty textiles were a prerequisite for finding PCDD/F in the distillation residues. The congeneric patterns of the identified PCDD/F in the distillation residues were found to be similar as those from household dust, sewage sludge, as well as those from soil, sediments, and street dust. The investigations clearly show that perchloroethylene is not linked to PCDD/F formation. The freshly produced, commercial perchloroethylene as well as laboratory-distilled perchloroethylene did not contain any detectable quantities of PCDD/F. Also, the possibility of PCDD/F formation through decomposition reactions of the solvents during the dry cleaning process can be excluded on the basis of existing data.  相似文献   

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Various paper products and cardboard containers produced from bleached or unbleached cellulose and from recycled paper were investigated. In coffee filters and milk cartons manufactured from chlorine-bleached cellulose, the amount of tetrachlorinated dibenzodioxins and dibenzofurans of the sum of the to xicity equivalents (TEQ) exceeds 90%. The use of unbleached or not chlorinebleached cellulose leads to products with significantly lower concentrations of PCDD/F congeners. However, the contents of higher chlorinated dibenzodioxins are higher in these products. In products from recycled paper, both the more toxic lower chlorinated PCDD/F with the pattern typical for chlorine bleached cellulose and high contents of higher chlorinated PCDD/F can be detected. The use of recycled paper for manufacturing kitchen tissues, paper serviettes, and paper handkerchiefs should be critically re-examined. *** DIRECT SUPPORT *** A00HP015 00003  相似文献   

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Surfaces of many sports fields, playgrounds and paths in Germany are covered with red slag ?Kieselrot”. Kieselrot is extremely high contaminated by polychlorinated dibenzodioxines and dibenzofurans. Mean PCDD/F-concentration in surface layers of 35 locations in Hessen is 45 500 ng I-TE/kg. PCDD/F-contents range from 1 000 to 250 ng I-TE/kg within 10 cm under surface layers and from 6 000 to 600 ng I-TE/kg in top soils of three metres wide peripheral areas. Concentration in subsoils is a function of depth (n=18, r=?0,741), concentration in topsoils of peripheral areas is a function of distance from large sports fields (n=14, r=?0,881) or small sportsfields (n=23, r=?0,742), respectively. A 15 metres wide and 10 centimetres deep peripheral area contains 0,8 g I-TE PCDD/F. The pollution of surroundings and further observations indicate that ?Kieselrot-areas” must be regarded as important dioxin sources.  相似文献   

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Background

Soil-background values of PCDD/F concentrations are usually conveniently displayed as toxic equivalent (TEq), being a bulk parameter of all relevant 7 PCDD- and 10 PCDF-congeneres, chloro-subsidized at the 2nd, 3rd, 7th and 8th carbon atom. Data here are ample, not so survey on congenere/homologue patterns occurring in soils. The sufficient number of samples taken within this analysis allowed first a well-grounded evaluation.

Results

OCDD proved to be the dominant congenere in all samples (forest and agriculture), however, in considerably different concentrations. As expected, highest level was detected in forest organic layers, followed by forest top soils, cropland- and grassland top soils. Although highest in concentration, OCDD only contributes to 0.17% (both forest organic- and top soil layer), respectively, 0.4% (cropland) and 0.3% (grassland) to TEq. The influence of lower chlorinated homologues on TEq is strongest in forest top soils (72%) followed by 67% (forest organic layers), cropland top soil (63%) and grassland (61%). Although all homologue patterns (forest and agriculture) give a fairly similar picture, a test of significance (χ 2) proved a different population of forest samples.

Conclusions

The resemblance of the homologue patterns throughout all utilization suggests that agent levels are explained mainly by diffuse atmospheric depositions rather than by specific land use input.
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Exhaust fumes of paraffin, beeswax and stearin candles without any further paint or decorative element were analysed for the toxicological important substance classes of PCDD/PCDF, PAH and short chain aldehydes. The candle waxes and wicks were investigated for chlorinated dioxins, furans and some known precursors. Toxicological risk assessment shows that emissions of the investigated candles are much lower than all administrative limitation values — even under “worst case conditions”. Thus, they do not produce a toxicological risk for human health.  相似文献   

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针对城市生活垃圾焚烧(MSWI)过程中二(口恶)英类的生成机制以及焚烧飞灰的组成,研究了MSWI飞灰中常见的钙化合物(CaO,Ca(OH)2,CaCl2,CaSO4及Ca(NO3)2)对前生体五氯酚(PCP)及六氯苯(HCB)生成二(口恶)英类的阻滞作用.结果表明,280℃下加热2 h,Ca(NO3)2,Ca(OH)2和CaO对PCP生成二(口恶)英类的总阻滞效率分别为93.7%,80.4%和98.9%,而CaCl2和CaSO4几乎没有效果.CaO对PCP和HCB混合物生成二(口恶)英类物质同样具有良好的阻滞效果.另外,探讨了上述钙化合物对PCP及HCB生成二(口恶)英类的阻滞作用机理.  相似文献   

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上海地区大气中二噁类分布特征的初步研究   总被引:1,自引:0,他引:1  
为了研究上海地区大气中二噁英(PCDD/Fs)的污染水平、分布特征和相分配规律,分别选取了上海典型的工业区、居民区和郊区的采样点进行了大气样品的采集。通过对3个采样点的研究发现,上海地区的大气中二噁英的平均毒性当量浓度为0.201 pg/m^3,居民区最高,工业区其次,郊区最低。大气中二噁英排放的平均浓度属于典型的城市工业区水平。在常温下,大气中90%二噁英主要分布在颗粒物相中,从单体看,高氯代同系物主要分布在颗粒相中,而低氯代同系物则分布在气相当中。通过二噁英的气相/颗粒相分配系数Kp与蒸气压PL的关系式评价了污染物的气相/颗粒相分配行为。并应用Junge-Pankow模型预测了大气中的气相/颗粒相分配,通过与实测值的比较发现,上海地区大气中二噁英的气相/颗粒相分布十分接近于模型中的城市地区,郊区采样点和模型预测值最为吻合,工业区和居民区大气中的二噁英在颗粒物上的浓度则要高于模型预测值,对造成偏离的原因进行了分析,并对3个采样点周围的污染源进行了初步的探究。  相似文献   

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The emerging issue of electronic wastes (e-waste) and the associated environmental problems has gained considerable attention from the scientific community in recent decades. In the present study, the levels of polybrominated diphenyl ethers (PBDEs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) in the surface soil obtained from the Taizhou e-waste recycling area of China were investigated. Also the correlation among these chemicals and previously published data of heavy metals, polycyclic aromatic hydrocarbons, and polychlorinated biphenyls was analysed. We determined that the pollution levels of eight PBDEs congeners were serious, ranging from 27.9 to 3128.4 μg/kg. The concentration of PCDD/Fs was in the range of 218.3–3122.2 pg/g with a mean value of 659.5 pg/g. The PBDEs were not well-correlated with organic pollutants (PAHs and PCBs) in soil, whereas PCDD/Fs exhibited a significant positive correlation with the PCBs. The higher levels of persistent organic pollutants may pose potential adverse effects to soil quality and human beings and needs to be properly managed and remediated.  相似文献   

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