Toxicity evaluation by using intact sediments and sediment extracts.
The toxicity of intact sediments and sediment extracts, from both an uncontaminated site and a site contaminated by pulp-mill effluents, was tested in a five months study. The deposit-feeding amphipod Monoporeia affinis was exposed in soft-bottom flow-through water microcosms. To examine potential toxicity a set of reproduction endpoints was used including fecundity and different embryo aberrations such as malformed eggs. Among extracts, the aliphatic/monoaromatic and diaromatic fractions along with the total extract were shown to cause the highest toxicity measured as malformed eggs, while the polyaromatic fraction caused toxicity at background levels. A comparison between sediment extracts and pulp mill contaminated intact sediment, however, showed no toxicity of the intact sediment. Thus, the extraction procedure seems to increase bioavailability and subsequently toxicity as compared to the intact sediments in situ. In toxicity testing using fractionated extracts of sediments in a toxicity identification evaluation (TIE) procedures, caution should therefore be taken when assessing bioavailable contaminants in contaminated areas. This should be taken in account both in determining remediation priorities as well as in ecological risk assessments.
Eriksson Wiklund
Ann-Kristin
AK
Department of Applied Environmental Science, Stockholm University, SE-10691 Stockholm, Sweden. annkristin.eriksson@itm.su.se
Dag Broman
Brita Sundelin
BS
D033304:Amphipoda / Q000187:drug effects* / Q000502:physiology; D000818:Animals; D047108:Embryonic Development / Q000187:drug effects; D004784:Environmental Monitoring / Q000379:methods / Q000706:statistics & numerical data*; D004785:Environmental Pollutants / Q000032:analysis / Q000633:toxicity*; D019015:Geologic Sediments / Q000032:analysis*; D006838:Hydrocarbons / Q000032:analysis / Q000633:toxicity*; D016015:Logistic Models; D010209:Paper; D012098:Reproduction / Q000187:drug effects; D013548:Sweden; D018675:Toxicity Tests / Q000379:methods; D014865:Waste Disposal, Fluid
D004785:Environmental Pollutants; D006838:Hydrocarbons