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Decomposition of pine-litter organic matter and chemical properties of upper soil layers: transect studies
1997
Breymeyer, A. | Degorski, M. | Reed, D. (Institute of Geography and Spatial Organization PAS, Twarda 51/55, 00-818 Warsaw (Poland))
Leeches as indicators of dietary mercury exposure in non-piscivorous waterfowl in central Ontario, Canada
1997
McNicol, D.K. | Mallory, M.L. | Mierle, G. | Scheuhammer, A.M. | Wong, A.H.K. (Canadian Wildlife Service, Ontario Region, 49 Camelot Drive, Nepean, Ontario K1A 0H3 (Canada))
Effects of storage conditions of biological materials on the contents of organochlorine compounds and mercury
1997
Boer, J. de | Smedes, F. (DLO-Netherlands Institute for Fisheries Research, P.O. Box 68, 1970 AB IJmuiden (Netherlands))
Modelling leaching of inorganic Hg(II) in a Scandinavian iron-humus podzol — validation and long-term leaching under various deposition rates
1997
Schlüter, K. | Gäth, S.
Increasing mercury contents are reported from freshwater systems and fish in northern Europe and North America. Mercury input from soils is a major source with the leaching being affected by increased atmospheric mercury deposition compared to pre-industrial times and by other environmental conditions such as acid rain. The results of a mathematical model-calculation of vertical inorganic Hg(II) leaching in a Scandinavian iron-humus podzol under different atmospheric input rates of mercury are presented. Leaching under background rain conditions was calculated to be considerably stronger than under acid rain conditions. Increasing fractions of deposited soluble or solute atmospheric mercury were leached from the Of₍ₕ₎-horizon with decreasing soil content of soluble mercury under acid rain conditions; this effect was less pronounced under background rain conditions. The steady state concentrations of soluble mercury of the upper soil horizons were calculated and compared with the actual concentrations of total (= soluble + insoluble mercury) and extractable (= estimate of soluble) mercury measured in these horizons. The results indicate that even if the deposition of airborne mercury to soil is strongly reduced, the total mercury content of the soil decreases only slowly. It may take decades or even centuries before a new steady state concentration of total mercury is established in the soil. The decrease of the mercury concentration in the Of₍ₕ₎-horizon is probably largely dependent on the turnover of organic matter, binding most of the deposited airborne mercury in an insoluble form. Hence, present day mercury leaching is likely to be dominated by mercury deposited during former times and temporarily retained in an insoluble form in the organic matter.
Показать больше [+] Меньше [-]A comparison of the bivalve species Donax deltoides and Mytilus edulis as monitors of metal exposure from effluent discharges along the Ninety Mile Beach, Victoria, Australia
1997
Haynes, D. | Leeder, J. | Rayment, P. (Gippsland Water, PO Box 348, Traralgon 3844 (Australia))
Total mercury and methylmercury in sediments and in the polychaeteNereis diversicolor at Groot Buitenschoor (Scheldt estuary, Belgium)
1997
Muhaya, B. B. M. | Leermakers, M. | Baeyens, W.
Total mercury (Hg) and methylmercury (MeHg) concentrations were determined in sediments and in the polychaete wormNereis diversicolor at 13 stations of a brackish water intertidal mudflat of the Scheldt estuary. Hg and MeHg concentrations in sediments ranged from 144 to 1192 ng g⁻¹ dw and from 0.8 to 6 ng g⁻¹ dw, respectively. Both Hg and MeHg concentrations increased with an increase of organic matter (OM) content and fine grain fraction. In contrast, Hg accumulation byN. diversicolor was significantly (p<0.05) higher at stations with sandy sediments (mean value: 125 ng g⁻¹ dw) than at stations with muddy sediments (mean value, 80 ng g⁻¹), probably because Hg availability for bioaccumulation at muddy stations was reduced by high OM content of the muddy sediments. MeHg accounted for an average of 0.7% of the total Hg in sediments and 18% of the total Hg inN. diversicolor. Seasonal variations significantly affected Hg concentrations in sediments and MeHg inN. diversicolor. Total Hg concentrations in sediments were significantly (p<0.05) higher in autumn and winter than in spring and summer whereas MeHg concentrations were lowest in winter compared to the other seasons. On the other hand, total Hg concentrations in the worms were lowest in spring whereas MeHg concentrations were significantly (p<0.01) higher in spring and summer than in autumn and winter.
Показать больше [+] Меньше [-]Increase of organochlorines and mercury levels in common guillemots Uria aalge during winter in the southern North Sea
1997
Joiris, C.R. | Tapia, G. | Holsbeek, L. (Laboratory for Ecotoxicology and Polar Ecology, Free University of Brussels (VUB), Pleinlaan 2, B-1050 Brussels (Belgium))
Organochlorines and other environmental contaminants in muscle tissues of sportfish collected from San Francisco Bay
1997
Fairey, R. | Taberski, K. | Lamerdin, S. | Johnson, E. | Clark, R.P. | Downing, J.W. | Newman, J. | Petreas, M. (Moss Landing Marine Laboratories, Moss Landing, CA 95039 (USA))
Fish contamination and human exposure to mercury in Tartarugalzinho River, Amapa State, Northern Amazon, Brazil: a screening approach
1997
Bidone, E.D. (Universidade Federal Fluminense, Niteroi, RJ (Brazil). Dept. Geoquimica) | Castilhos, Z.C. | Santos, T.J.S. | Souza, T.M.C. | Lacerda, L.D.
Effects of humic acid transport and transformation of mercury in soil-plant systems
1997
Wang, D.Y. (Southwest Agricultural Univ., Chongqing (China). Coll. of Resources and Environment) | Qing, C.L. | Guo, T.Y. | Guo, Y.J.