The primary purpose and object of the study has been to reveal in retrospect the evolving conditions which have affected Ball State UniversityMuncie, IN 47306

Albert Y.C. Fung. / Thesis (M.S.)--Chinese University of Hong Kong.

No description available.

An extensive review of all the avoidance apparatus which have been used to date in chemical avoidance tests and also an analysis of the trends and needs for new improved designs led to the design of a new avoidance apparatus. The new apparatus is a viable tool for analyzing the behavioral responses of fish to potentially toxic effluents in three dimensions. The method is quick, sensitive and relatively easy to use if sufficient fish stock is available. / The variable parameters of the avoidance reaction were three: (a) the type of the pollutant, (b) the injection system, and (c) the concentration of the pollutant. / Statistical analysis for the experiments included preliminary calculations, time series analysis, analysis of variance and Duncan's tests. / Preliminary tests evaluated the general disposition of fish in the channel, the influence of a water acclimation jet and also the effects of noise, light and temperature. Experiments were performed to define the optimal number of fish per experiment, the influence of video analysis and also of variability, adaptability and continuity. / The types of pollutants used were D.S.S. (dodecyl sodium sulfate)--a well-known reference pollutant, polymers, monomers, a plating industrial effluent and its components (Cr, Ni, Fe). / For all of these, horizontal and vertical distributions were produced together with avoidance curves and avoidance reaction representations. / The role of the avoidance reaction in relation to lethal and sublethal levels has been defined; after the evaluation of synergism and antagonism phenomena, proposed adjustments for safe toxicant levels have been estimated.

Thesis (M.P.H.)--University of Michigan, 1946.

Thesis (M.P.H.)--University of Michigan, 1946.

This work was undertaken in order to determine the extent and nature of PAH pollution In a freshwater riverine environment. An extensive survey of sediment, water and aquatic organisms was carried out to investigate sources of PAH, physicochemical relationships occurring in the water and sediment, the extent of bioaccumulation and the potential for bioconcentration through the food chain. Laboratory studies were designed to investigate the likely mode and extent of uptake of PAH by Noemacheilus barbatulus (L.), Glossiphonia complanata (L.) and Lymnaea peregra (MUller), the ability of these species to metabolise PAH compounds and the extent of depuration. All sediment PAH profiles were similar and indicative of an anthropogenic pyrolytic origin. Urban/road runoff was considered to be a major influence on sediment PAH concentrations. point sources consisted of industrial waste sewage and runoff containing used engine oil. , All sites were affected by diffuse PAH pollution. At certain sites and at times of heavy rainfall this is overlain by a greater input of PAH to the sediment from point sources. Positive linear relationships have been demonstrated between total and individual PAH content and organiC matter content in sediments throughout a range of particle sizes. A similar PAH profile was found in each sediment size fraction, thus organisms selectively removing certain sized particles are not being exposed to differing ratios of PAH compounds. The river system seems to be in a state of nearequilibrium with regard to the partitioning of PAH between bedload sediment, suspended sediment, water and interstitial water. Adsorption and desorption processes occur in two phases, the first being almost instantaneous and the second being a slower approach to equilibrium. There is no- evidence of PAH's being bioconcentrated through the food chain. Uptake by tubificid worms occurs by the ingestion of contaminated sediment. Uptake by Cottus goblo (L.), N. barbatulus, L. peregru, G. complanata and Erpobdella octoculata (t.) occurs mainly through water and was shown to be rapid. N. barbatulus, L. peregra and G. complanat~ have the capacity to metabolise PAH compounds to harmful derivatives and it is likely that C. gobio and E. octoculata also have this capability. Depuration of BaP and metabolite compounds was relatively slow. Prolonged exposure to low levels of BaP in the environment may lead to a buildup of DaP and metabolite compounds in these organisms.

No description available.

No description available.

No description available.