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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   
43.

Objective

Flood sediments were investigated due to the extreme flood situation around Dresden in August 2002

Method

The samples have been analyzed by screening inorganic and organic pollutants.

Results

It was observed that As, Pb, Cd, Zn, Cu, B and other heavy metals as well as DDT, PCB and Benzo [a] pyren were significantly enriched.

Conclusion

Depending on geogenic and anthropogenic impacts, the spatial distribution of these contaminants was different. Organic compounds were dislocated down stream from Czech Republic along the Elbe River. Because of the old ore mining, samples near the Mulde and Wei\eritz Rivers showed high metal pollution.

Perspective

More detailed and systematic investigations should be undertaken in the Elbe and Mulde river systems.  相似文献   
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Trichlorofluoromethane, in concentrations of 80, 400, 2 000, 10 000 and 50 000 ppm, was administered to rats of both sexes (Sprague Dawley) by inhalation exposure. 2 000 ppm in air (= 11 200 mg/m3) amount to twice the MAK value of 1 000 ppm. At exposure times of 4 hours this corresponds to the MAK value defined for an 8 hour workday. Unscheduled DNA synthesis (UDS) was measured in single-cell suspensions of hepatocytes, pulmonary epithelial cells and lymphocytes of the spleen, respectively. In the pulmonary cells concentrations of 2 000, 10 000 and 50 000 ppm of freon 11 lead to a significantly increased mean silver grain count compared to a negative control group. In spleen and liver cells increasing concentrations of R 11 tend to increase the incorporation of thymidine into the DNA of the cells. These changes of the extent of unscheduled DNA synthesis can, however, not be statistically verified.  相似文献   
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This study evaluated the toxicity of a single size 7.5 lead shot to passerines. No mortalities or signs of plumbism were observed in dosed cowbirds (Molothrus ater) fed a commercial diet, but when given a more natural diet, three of 10 dosed birds died within 1 day. For all survivors from which shot were recovered, all but one excreted the shot within 24 h of dosing, whereas, the dead birds retained their shot. Shot erosion was significantly greater (P < 0.05) when weathered shot were ingested compared to new shot, and the greatest erosion was observed in those birds that died (2.2-9.7%). Blood lead concentrations of birds dosed with new shot were not significantly different (P = 0.14) from those of birds exposed to weathered shot. Liver lead concentrations of birds that died ranged from 71 to 137 ppm, dry weight. Despite the short amount of time the shot was retained, songbirds may absorb sufficient lead to compromise their survival.  相似文献   
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