Grant: Discovery Grants Program - Individual

The overall objectives of this research program are to assess the physiological, growth, reproductive and developmental effects of exposure to mixtures of pharmaceuticals and personal care products (PPCPs) in aquatic organisms, including fish and hydra (small freshwater invertebrates). Waste water treatment plants (WWTPs) continuously release effluent containing trace levels of PPCPs into aquatic ecosystems. For example, the concentration of ibuprofen in a Canadian effluent was found to be up to 22 µg per L. Such chemicals are more likely to have chronic than acute effects, with exposure to low levels occurring for long periods of time. Two aspects of PPCPs which are particularly problematic are: they designed to have effects on biological systems by modifying important physiological/ biochemical functions; and, PPCPs are being continuously introduced into surface waters (pseudo-persistence) resulting in extended exposures to aquatic biota. Studies on rainbow trout (Oncorhynchus mykiss), Florida flagfish (Jordanella floridae) and Japanese medaka (Oryzias latipes), (the latter two are small model freshwater fish commonly used in developmental and toxicity studies) utilizing either partial life-cycle, or full life-cycle studies, will assess the ability to predict sublethal effects of early life-stage exposure to effluent contaminants, both individually, and in a combination of simple mixtures. Contaminant effects on rainbow trout early life stages will be compared to multi-generational effects on flagfish and medaka. Similar exposures to two species of hydra, the green hydra (Hydra viridissima) and the brown hydra (Hydra oligactis) will also be undertaken. Correlations between enzyme and other biomarkers, growth, reproductive endpoints and second generation health will be made in relation to specific exposure concentrations and exposure times. Exposure of fish to real treated sewage effluents of will be undertaken as part of the Southern Ontario Water Consortium using the in-situ laboratory presently under construction in Guelph. This will permit comparison of the impacts of exposure to dilute treated sewage effluent containing complex mixtures of contaminants to the effects observed in the laboratory involving controlled PPCP exposures and simple contaminant mixtures. This information will result in increased understanding of the impacts of such trace PPCP contaminants on the physiology, growth, reproduction, development and survival of fish populations. It will also assist in the development of better treatment processes to identify key contaminants and assist in developing better treatments to minimise the impacts of PPCPs in treated effluents. Rainbow trout and American flagfish responses will be compared at the whole organism, organ, tissue and biochemical levels of biological organisation to determine useful biomarkers of exposure and effects that successfully predict whole organism impacts. This proposed research program will enhance efforts to assess the impacts of such complex mixtures of chemicals to fish species in the wild as well as in laboratory situations, and to permit more precise understanding of the impacts of such contaminant exposure on different spatial and temporal scales. Such knowledge will increase our ability to manage contaminants in complex effluents such as treated sewage to safeguard the health of important fish populations for the benefit of all Canadians