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Effects of the pesticides thiotox, dichlorvos and carbofuran on the test fish Mystus vittatus
1980
Verma, S.R. | Rani, S. | Bansal, S.K. | Dalela, R.C. (DAV College, Muzaffarnagar (India). Dept. of Zoology, Pollution Relevant Research Lab.)
A quantitative index of synergism, anatagonism and additivity has been measured experimentally in the fish Mystus vittatus for three pesticides viz. Thiotox (Endosulfan) (T), Dichlorvos (D) and Carbofuran (C). For a combination of two pesticides, the dose of the one pesticide of a pair was fixed at the no-effect level while the dose of the second pesticide was increased until the entire dose response curve was obtained. To evaluate interactions of three pesticides, the previous pair of pesticides was kept fixed at their combined TL(,0) level, and the third pesticide was increased and again a dose-response curve was obtained. From the results obtained, it is shown that a particular combination could be synergistic, antagonistic or additive, depending on the relative doses employed. In the present study (T + D)/C combination was most synergistic (toxic) in nature while D/T and C/T were least toxic antagonistic in their effects. However, T/D, (C + T)/D, C/D and D/C combinations were additive in nature. (D + T)/C, (D + C)/T, (T + C)/D and (C + D)/T combinations were found less synergistic in nature than (T + D)/C.
Afficher plus [+] Moins [-]Microbial and non-biological decompostion of chlorophenols and phenol in soil
1980
Baker, M.D. | Mayfield, C.I. (Waterloo Univ., Ont. (Canada). Dept. of Biology)
The aerobic and anaerobic degradation of phenol and selected chlorophenols was examined in a clay loam soil containing no added nutrients. A simple, efficient procedure based on the high solubility of these compounds in 95 per cent ethanol was developed for extracting phenol and chlorophenol residues from soil. Analysis of soil extracts with UV spectrophotometry showed that phenol, o-chlorophenol, p-chlorophenol, 2,4-dichlorophenol, 2,6-dichlorophenol and 2,4,6-trichlorophenol were rapidly degraded, while m-chlorophenol, 3,4-dichlorophenol, 2,4,5-trichlorophenol and pentachlorophenol were degraded very slowly by microorganisms in aerobically-incubated soil at 23 deg C. Both 3,4,5-trichlorophenol and 2,3,4,5-tetrachlorophenol appeared to be more resistant to degradation by aerobic soil microorgamisms at 23 deg C. None of the compounds examined were degraded by microorganisms in anaerobically-incubated soil at 23 deg C. Direct microscopic observation revealed that phenol and selected chlorophenols stimulated aerobic and to a lesser extent, anaerobic microbial growth in soil, and aerobic soil bacteria were responsible for the degradation of 2,4-dichlorophenol in aerobically-incubated soil at 23 deg C. Phenol, o-chlorophenol, m-chlorophenol, p-chlorophenol and 2,4-dichlorophenol underwent rapid non-biological degradation in sterile silica sand. Non-biological decomposition contributed, perhaps substantially, to the removal of some chlorophenols from sterile aerobically-incubated soil and both sterile and non-sterile anaerobically-incubated soil
Afficher plus [+] Moins [-]Quantitative aquatic biological indicators
1980
Phillips, David J. H.
Indoor air pollution: an emerging health problem
1980
Mediterranean pollution
1980
Jenkins, S. H (Samuel Harry)
Background parameters of atmospheric precipitation chemical composition as siting criterion for global monitoring stations
1980
Selezneva, E.S. (State Committee for Hydrometeorology and Control of the Natural Environment, Moscow (USSR). Voeikov Main Geophysical Observatory)
Study of pollutant impact on freshwater ecosystems
1980
Andrushaitis, G.P. | Tsymdim, P.A. (AN Latuijskoj SSR, Riga. Inst. Biologii)
Comments on the specification on network stations for monitoring the variability of atmospheric trace constituents significant for climate
1980
Hanson, K.J.
Progress in the study of contamination effects in the marine environment
1980
McIntyre, A.D. (Department of Agriculture and Fisheries for Scotland, Aberdeen (UK). Marine Lab.)
Study of wild-animal pollution by pesticides (methodical aspects)
1980
Voronova, L.D. | Denisova, A.V. (Ministry of Agriculture, Moscow (USSR). Central Scientific Research Lab. of Nature Protection)