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Investigations on Interception and Translocation of Airborne 85Sr, 131I, 137Cs in Beans, Spinach and Radish Plants Texte intégral
1998
Singhal, R. K. | Narayanan, U. | Bhat, I. S.
The work reported here deals with the study of interception/deposition and translocation of ⁸⁵Sr, ¹³¹I, and¹³⁷ Cs in three different types of vegetables i.e. beans (Phasoolus vulgaris), spinach (Spinicia olericia) and radish (Raphanous sative) following redionuclides release to the environment. Activity was injected in the experimental chamber in the form of aerosols having a size distribution of 0.3–1.0 µm (AMAD). Plant samples were collected soon after the injection for the evaluation of interception/deposition factors (IF/DF) for the different parts of the plants, as well as for the whole plant and the washable fraction of the deposited activity and its variation with time. The evaluated IF/DF shows a minimum value of 0.12 m³ kg⁻¹ for ⁸⁵Sr in case of spinach whole plant and maximum value of 1.93 m³ kg⁻¹ for ¹³¹I in case of beans whole plant. Translocation factors (TF) have also been evaluated for the activity that migrates from the above soil plant parts to the root and its variation with time. The evaluated TF shows a range of 7.27 × 10⁻³ to 136 × 10⁻³.
Afficher plus [+] Moins [-]Airborne Pollution in Five Drainage Basins in Eastern Finnmark, Norway: an Evaluation of Overbank Sediments as Sampling Medium for Environmental Studies and Geochemical Mapping Texte intégral
1998
Langedal, Marianne | Ottesen, Rolf Tore
To study whether airborne pollution can be detected in overbank sediments, samples collected from five overbank sediment profiles in eastern Finnmark, Norway, at 1 cm depth intervals, were subjected to chemical analysis and ²¹⁰Pb dating. The studied drainage basins constitute parts of an area polluted by emissions from two Ni-Cu smelters in Russia. In the most polluted catchment area, the surface sample showed a 5-fold higher Ni concentration and a 3-fold higher Cu concentration than the pre-industrial sediments at depth. The increases started at the same time as the smelters. Slight Ni increases were also detected in the neighbouring drainage basin, while no significant concentration change was seen in drainage basins previously shown to be only weakly influenced by the smelter emissions. In the most polluted drainage basin, the increase in Ni accumulation rate did not equal the airborne deposition rate. Selective surface erosion of fine grained particles with adhering airborne Ni has probably caused excess Ni accumulation in both overbank and lake sediments. On the contrary, opening of minerogenic point sources may dilute the pollutant concentrations in the drainage sediments. Thus, dating of the sediment profiles is necessary to determine the airborne pollutant accumulation rates. However, dating is not necessary to map the resultant concentration increase, that may show the increased exposure of humans and biota in contact with the sediments.
Afficher plus [+] Moins [-]An Emissions Inventory for Regional Atmospheric Modeling of Mercury Texte intégral
1998
Pai, Prasad | Heisler, S. (Steven) | Joshi, Aruna
Estimates of mercury emissions from individual sources and source categories are needed to understand relationships between the emissions and resulting deposition and to evaluate possible approaches to reducing those emissions. We have developed geographically-resolved estimates of annual average mercury emission rates from current anthropogenic sources in the 48 contiguous United States. These estimates were made by applying emission factors to individual facility operating data and to county-wide source activity levels. We apportioned the emissions to an Eulerian modeling grid system using point source coordinates and the fractions of county areas in each grid cell. Point sources account for about 89% of the 48-state total mercury emissions of 146.4 Mg/yr. Most of the emissions in the inventory are from combustion of mercury-containing fossil fuels and municipal waste, located primarily in the mid-Atlantic and Great Lakes states as well as in the Southeast. The major uncertainties in the emission estimates are caused by uncertainties in the emission factors used to develop the estimates. This uncertainty is likely a result of variability in the mercury content of the combusted materials and in the removal of mercury by air pollution control devices. The greatest research need to reduce uncertainties in mercury emission estimates is additional measurements to improve emission factors.
Afficher plus [+] Moins [-]Use of Soft Data in a GIS to Improve Estimation of the Volume of Contaminated Soil Texte intégral
1998
Hendriks, L. A. M. | Leummens, H. | Stein, A. | de Bruijn, P.
In the practice of soil remediation, organoleptic observations such as the smell or the colour of contaminated soil play an important role when determining well-defined volumes of contaminated soil. A GIS is then used to combine quantitative measurements with such soft data. In this study general procedures concerning how to deal with this type of observations are presented. The procedures were applied to a former gas works site, which was contaminated with cyanide and polycyclic aromatic hydrocarbons in the Netherlands. The volume of contaminated soil was determined. Use of soft data reduced the uncertainty in the volume of contaminated soil with 4 to 16%.
Afficher plus [+] Moins [-]Investigations on interception and translocation of airborne (85)Sr, (131)I, (137)Cs in beans, spinach and radish plants
1998
Singhal, R.K. (Bhabha Atomic Research Center, Bombay (India). Health Physics Div.) | Narayanan, U. | Bhat, I.S.
Lead (Pb) in Arctic char (Salvelinus alpinus) from oligotrophic alpine lakes: Gills versus digestive tract
1998
Kock, G. (Innsbruck Univ. (Austria). Inst. of Zoology and Limnology) | Triendl, M. | Hofer, R.
Effect of organic materials on partitioning, extractability and plant uptake of metals in an alum shale soil
1998
Narwal, R.P. (Agricultural Univ. of Norway, Aas (Norway). Dept. of Soil and Water Sciences) | Singh, B.R.
The effects of acid precipitation and ozone on the ectomycorrhizae of red spruce saplings
1998
Roth, D.R. (Cornell Univ., Ithaca, NY (USA). Dept. of Natural Resources) | Fahey, T.J.
Effects of alum-treated waste water sludge on barley growth
1998
Wang, F.H. (Quebec Univ., Ste-Foy, Que. (Canada). Inst. National de la Recherche Scientifique) | Couillard, D. | Auclair, J.C. | Campbell, P.G.C.
Nitrogen and phosphorus leaching from fertilizer applied on golf course: lysimeter study
1998
Wong, J.W.C. (Hong Kong Baptist Univ., Kowloon (Hong Kong). Dept. of Biology) | Chan, C.W.Y. | Cheung, K.C.