12 resultados para radioactivity
em Aquatic Commons
Resumo:
(PDF contains 2 pages.)
Resumo:
Radioactivity measured in samples from the NEA-Dumping-Site not only emanated from dumped barrels. Just as everywhere on the world also fallout from former nuclear weapon tests can be found there. Radionuclides which can emanate from different sources do not tell anything about their origin. To assess the fractions from various sources activity ratios from radionuclides can be used. There are different activity ratios for fallout and for waste from peaceful nuclear power engeneering. The comparison of the ratios of the plutonium isotopes Pu-238 and the sum of Pu-239 and Pu-240 (Pu-238/Pu-239,240) in benthic samples from the dumping site and from reference sites without waste dumping gives a clear hint. In the sampling period from 1980 to 2000 for samples from the dumping site this ratio increases significantly from 1986 on. Radioactivity emanating from the dumped barrels is regarded as causing this.
Resumo:
A subject of a change of authorised limits in 1994 for the discharge of liquid radioactive waste by the reprocessing plant Sellafield (UK) was an increase of these limits for certain radionuclides (3H, 14C, 60Co, 99Tc and 129I). It is investigated now how the radioactivity in marine biota from the North Sea and subsequently the public radiation exposure by ingestion has developed in the years since 1994. This is based on a compartment model for the Northeast Atlantic. Discharges of the reprocessing plants Dounreay (UK) and La Hague (F) are included in the assessment. It is deduced that about 60 % of 137Cs in the North Sea originate presently in the remobilisation of old Sellafield discharges from the Irish Sea sediment. A comparison with measured biota data shows that the model is conservative in the most cases. The public radiation exposure from ingestion of fish, crustaceans and molluscs from the central North Sea as the sum over 12 considered radionuclides has decreased from 1992 to 1998 from 0,13 to 0,08 μSv·y–1. For the southward and northward joined regions it was a little bit smaller with a similar decreasing trend.
Resumo:
The identification of artificial radionuclides in fish involves some diffculties, because the quantities of these nuclides are very low (10-16 to 10-10 g/kg). The procedures have to be done very carefully. The sample preparation, the radiochemical analyses and the final preparation of the samples for the detection of the radioactivity of strontium-90, plutonium-238, -239, -240 and americium-241 are briefly described. The levels of artificial radioactivity in some species of fish from the North Sea are shown. The additional exposure to radiation by artificial radionuc1ides by ingestion of fish amounts only to about 0,02 % of the mean exposure to natural radiation. Nevertheless further monitoring of radioactivity should be continued in order to ensure that changes can be detected in time.
Resumo:
This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 30th March, 1977. The report contains sections on radioactivity discharges and fisheries interests, fish mortality at Henthorn on the River Ribble, and fisheries activities. The section on radioactivity discharges looks at pollution caused by radioactive discharges from Windscale to the Irish Sea and possible effects on fish. The section on fisheries activities includes information on artificial propagation of salmonids; fish mortalities; silting in River Hodder; and the fish counter Winckley Hall. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
This is the report from the Mersey and Weaver Fisheries Advisory Committee meeting, which was held on the 21st June, 1978. It covers information on the monitoring of radioactivity in migratory fish, fishing offences and prosecutions and the income from sale of rod and line licences. It also includes the report by the area fisheries officer on river conditions and fishing, and an update on Tintwistle hatchery and Worthington Stock Pools. Included in this report is also the pollution incidents, fish mortalities, fisheries management and the stocking numbers of coarse fish, brown trout and rainbow trout by the Angling Associations. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
This is the report from the South and West Cumberland Fisheries Advisory Committee meeting, which was held on the 26th June, 1978. It covers information on the monitoring of radioactivity in migratory fish, fishing offences and prosecutions and the income from the sale of rod and line licences. It also includes the review of discharge consent conditions, illegal netting and water quality. It also covers the report by the area fisheries officer on river conditions and fishing, migratory fish movements, and an update on Holmwrangle hatchery. Included in this report is also the fish mortalities, survey and research work on Ennerdale Lake, In-River engineering works on the Derwent, Calder, Irt and Esk, and the stocking numbers of salmon and sea trout by the Water Authority. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
This is the report from the Eden and District Fisheries Advisory Committee meeting, which was held on the 27th June, 1978. It covers information on the monitoring of radioactivity in migratory fish, fishing offences and prosecutions, and the income from the sale of rod and line licences. Also included is the review of discharge consent conditions and illegal netting, and the report by the area fisheries officer. This covers information on river conditions and fishing, migratory fish movements, Holmwrangle hatchery, fish mortalities, fish diseases, coarse fish removals from Brunstock Beck, and In-River engineering works. Also included in the report is the stocking numbers of salmon and sea trout by the Water Authority. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
This is the report from the South Lancashire Fisheries Advisory Committee meeting, which was held on the 28th June, 1978. It covers information on the monitoring of radioactivity in migratory fish, fishing offences and prosecutions, the income from the sale of rod and line licences, the review of discharge consent conditions, illegal netting and issues relating to Worthington and Stocks reservoir. It also covers the report by the area fisheries officer on river conditions and fishing, migratory fish movements, Langcliffe hatchery, fish mortalities and stocking numbers of brown trout, rainbow trout and coarse fish by the Angling Associations. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
This is the report from the Lune, Wyre and Furness Fisheries Advisory Committee meeting, which was held on the 3rd July, 1978. It covers information on the monitoring of radioactivity in migratory fish, fishing offences and prosecutions, the income from sale of rod and line licences, the review of discharge consent conditions, illegal netting, the Morecambe and Heysham sewerage scheme and fish counting work. It also covers the report by the area fisheries officer on river conditions and fishing for Lune, Furness, Wyre and tributaries. Also covered in the report is information on migratory fish movements, fish monitoring stations, Middleton hatchery, fish mortalities, fish diseases, biological work and stocking numbers of brown trout, rainbow trout and coarse fish by the Angling Associations. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
This is the report from the Lune, Wyre and Furness Fisheries Advisory Committee meeting, which was held on the 15th January, 1979. It covers information on the proposed net limitation order and new fishery byelaws for the Rivers Lune and Wyre, the proposed byelaws for Skerton Weir, issues with the electric fish diversion screens for the Lune and the Wyre, and the monitoring of levels of radioactivity in migratory fish. The section on the report by the area fisheries officer on fishing activities includes river conditions and fishing for the Lune, Wyre and Furness and figures for migratory fish counted at Haverthwaite on the River Leven, Broadraine, Forge Weir and Skerton Weir on the River Lune and Duddon Hall. Also included is an update on Middleton Hatchery, fish disease, fish mortalities and net catch figures for 1978 of grilse, salmon and sea trout for the Lune, Kent, Leven and Duddon. The Fisheries Advisory Committee was part of the Regional Water Authorities, in this case the North West Water Authority. This preceded the Environment Agency which came into existence in 1996.
Resumo:
This is the Impact Assessment of ionising Radiation on Wildlife document produced by the Environment Agency in 2001. This report describes the behaviour and transport of radionuclides in the environment, considers the impact of ionising radiation on wildlife, and makes recommendations on an approach for the Impact assessment of ionising radiation on wildlife for England and Wales. The assessment approach focuses on three ecosystems representative of those considered potentially most at risk from the impact of authorised radioactive discharges, namely a coastal grassland (terrestrial ecosystem); estuarine and freshwater ecosystems. The likely scale of the impact on wildlife is also assessed in light of a preliminary analysis based on this assessment approach. The report demonstrates the behaviour and transfer of radionuclides in a number of different ecosystem types. Particular emphasis is placed on exposure pathways in those ecosystems most likely to be impacted by the authorised discharges of radioactivity within England and Wales. The use of biomarker techniques is reviewed in the report, and their application to the study of exposure to multiple contaminants is discussed.