Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4530829 | Aquatic Toxicology | 2008 | 12 Pages |
Abstract
Five oyster farms in Port Stephens, Australia were studied to identify consequences of using creosote-treated posts and the risks posed by removing the posts. Gas chromatography coupled with mass spectrometry (GC/MS) was used to measure polycyclic aromatic hydrocarbons (PAHs) and phenols in sediments, timber, water and oyster tissue. Before posts were removed, the total PAHs in surface sediment on farms was 24.1 mg kgâ1 dry weight. This increased to 45.5 mg kgâ1 dry weight after the posts were pulled out and remained significantly higher 6 months later at 59.7 mg kgâ1 dry weight. A similar increase was found in deeper sediments. The sediment attached to creosote-treated posts had a total concentration of PAHs of 484-2642 mg kgâ1 dry weight, while the corresponding value for the sediment on tar-treated posts was only 30.7 mg kgâ1 dry weight. The surface timber of creosote-treated posts had high levels of PAHs and an average post contained 43 g of PAHs. The total PAHs dispersed to the environment when a creosote-treated post was pulled out was at least 0.67 g. The main species were PAHs with low-molecular weights: fluoranthene, phenanthrene, pyrene, acenaphthylene and chrysene. Benzo(a)pyrene represented 1-10% of PAHs in most samples. Bioassays with creosote-contaminated sediment revealed that Sydney rock oysters (Saccostrea glomerate) and Pacific oysters (Crassostrea gigas) accumulated PAHs at (mg kgâ1 wet tissue weight): 11.3-15.3 and 35.5-47.9, respectively, when exposed for 5 days to water with <1 μg lâ1 PAHs. Wild oysters growing on creosote-treated posts had high levels of phenols (0.09-6.92 mg kgâ1 wet weight) and PAHs (0.59-1.01 mg kgâ1 wet weight). The dilemma posed by removing creosote-treated posts and dispersing carcinogenic, bioavailable contaminants needs to be managed in light of risks to human health and estuarine ecology.
Keywords
Related Topics
Life Sciences
Agricultural and Biological Sciences
Aquatic Science
Authors
Paul T. Smith,