Submitted to: Society of Environmental Toxicology and Chemistry Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 6/10/2004
Publication Date: 7/1/2004
Citation: Lizotte Jr, R.E., Moore, M.T., Smith Jr, S., Steinriede Jr, R.W. 2004. Novel method for the examination of leaf litter contamination. Mid-South Regional Society of Environmental Toxicology and Chemistry Abstracts. p. 15.
Technical Abstract: Leaf litter is an important part of an aquatic system, as a source of course particulate organic matter (allochthonous input), and is utilized (via processing) by a diverse group of aquatic organisms such as bacteria, fungi and macroinvertebrates. Past focus of fate and effects of contaminants in aquatic systems has been almost exclusively on water and sediment with relatively little research on aspects of macrophytes and/or vegetative litter. This research provides basic methodology for examining the fate and effects of pesticide contamination in leaf litter. Leaf litter was simulated using Norway maple leaves (Acer platanoides) contained within 0.5 cm diameter mesh polyester bags placed within a constructed wetland amended with 160 ug/L diazinon, in a one-time pulse exposure. Fate and effects were examined spatially and temporally across three wetland cells for 27 d. Concentrations of diazinon adsorption in leaf litter were measured via gas chromatography. Toxicity effects (measured as survival) were examined using Hyalella azteca exposed to 2 cm leaf discs cut from contaminated leaf litter for 48 h. Measured diazinon concentrations in leaf litter varied spatially and temporally and ranged from 35-2211 ug/kg with 5 of 15 samples having diazinon concnentrations below the detection limit of 5 ng/kg. Hyalella azteca survival also varied spatially and temporally in general agreement with leaf litter diazinon concentrations. Examination of leaf litter contamination using the described method in conjunction with sediment and water is a simple and useful aid in further assessing fate and effects of contaminants in aquatic systems.