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Environmental fate & pathways

Bioaccumulation: aquatic / sediment

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Administrative data

Endpoint:
bioaccumulation in aquatic species: invertebrate
Type of information:
experimental study
Adequacy of study:
key study
Study period:
17.1. -17.2. 1989
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EPA OTS 797.1830 (Oyster Bioconcentration Test)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
received from Sigma Chemical Company, St. Louis on 15 Septembt.tr 1988 - Anthraquinone (phenyI-ring) UL-14C, 3.5 mCi; 6.13 mCi/mmoIe;
The sample was identified by the study sponsor to be 99.81% active Ingredient (AI.).
Radiolabelling:
yes

Test solutions

Vehicle:
yes
Details on preparation of test solutions, spiked fish food or sediment:
A stock solution, at a concentration of 0.9528 mg A.I/mL was prepared by adding 0.3453 grams of non-radlolabeled Anthraquinone (dissolved In acetone. CAS #87-64-1) end 50 ml of a radiolabeled stock solution (0.7165 mg 14C Anthraquinone/mL acetone) to a total volume of 400 ml with acetone. A second stock solutions at a concentration of 0.0717 mg/mL Anthraquinone was prepared by diluting 10 mL of a radIiolabeled stock solution (0.7186 mg 14C Anthraquinone/ml aoetone) to a total volume of 100 ml with acetone. Syringe delivery mechanisms and 50-mL Glenco gas-tight syringes, located above of each treatment and solvent control aquariums were calibrated to deliver 0.21 ml of the approprate stock solution of test material or solvent to 2.0 l of seawater during each dilution cycle. The solvent controIl solution contained 0.011 mL/L acetone, which was equivalent to the concentration of acetone present in each treatment level aquarium

Test organisms

Test organisms (species):
other aquatic mollusc: Crassostrea virginica
Details on test organisms:
The oyasters used during this study were received on 19 December 1988 from Aquacultural Research Corporation, Dennis, Massachusetts. The test organisms were held for 29 days prior to test initiation under a photoperiod of 18 hours light and 6 hours darkness. During this holding period oysters were fed daily with alga.

Study design

Route of exposure:
aqueous
Test type:
flow-through
Water / sediment media type:
natural water: marine
Total exposure / uptake duration:
17 d
Total depuration duration:
14 d

Test conditions

Test temperature:
16-19°C
pH:
7.7. - 8.0
Dissolved oxygen:
6.1 - 9.6 mg/L
Salinity:
26-34‰
Nominal and measured concentrations:
nominal test concentrations of 10 and 0.75 µg/L
mean measured concentrations: 7.2 (+/- 0.4) and 0.78 (+/- 0.05) µg/L Anthraquinone (Day 0 - 17).
Details on estimation of bioconcentration:
The BCF at stedy state was calculated calcuIated by dividing the mean equilibrum 14C residue concentration in tissue by the mean measured cocnetration of the anthraquinone in the test solution during the same period. 95% confidence interval associated with each BCF was calculated based onmean measured 14C residue concentrations in tissue and water.

Results and discussion

Bioaccumulation factoropen allclose all
Type:
BCF
Value:
140 other: X
Basis:
other: mean equilibrum 14C residue concentration in tissue by the mean measured cocnetration of the anthraquinone in the test solution during the same period
Calculation basis:
steady state
Remarks on result:
other: Conc.in environment / dose:7.1 µg/L
Type:
BCF
Value:
110 other: X
Basis:
other: mean equilibrum 14C residue concentration in tissue by the mean measured cocnetration of the anthraquinone in the test solution during the same period
Calculation basis:
steady state
Remarks on result:
other: Conc.in environment / dose:0.78 µg/L
Depuration
Elimination:
yes
Parameter:
DT50
Depuration time (DT):
24 h
Details on kinetic parameters:

- Uptake rate constant (k1):240, 150
- Depuration (loss) rate constant (k2):1.7 ; 1.3

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Executive summary:
g/L Anthraquinone in the test solutions and corresponding concentration of 14C-residues

Eastern oysters (Crassostrea virginica) were continuously exposed to nominal concentration of 10 and 0.75 µg/L of Anthraquinone in seawater for 17 days after which 36 oysters from each exposure level were transfer to separate aquaria containing flowing uncontaminated seawater for a 14-day depuration period. The concentration of Anthraquinone in the exposure test solutions and oyster tissues were monitored on day 0 (water only) 1, 3, 7, 10, 14 and 17 of the exposure period and days 1, 3, 7 and 14 of the depuration period.

Radiometric analysis of water and oysters tissues received the following:

1.The concentration of aqueous14C residues in the exposure system remains relatively constant at both treatment levels throughout the 17 -day exposure period. Result of these analyses established mean measured exposure concentrations (standard deviations) of 7.1 (+/-0.4) and 0.78 (+/-0.05) µg/L Anthraquinone (Day 0 -17). Throughout the 14 day depuration period, concentration of14C -residues present in the water of the depuration aquaria for both treatment levels (10 and 0.75 µg/L, nominal) remain below the limits of radiometric detection (2.0 and 0.19 µ g/L, respectively).

2. The concentration of14C -residues in the tissue of oysters exposed to Anthraquinone at both treatment level, reached steady state by day 1 of the exposure period. The mean (95% confidence interval) steady-state bioconcentration factor (BCF) for14C -residues in the tissues of oyster exposed to 7.1and 0.78 µg/L Anthraquinone (Day 1 -17) were 140X (90X - 190X) and 110X (94X - 130X) respectively. Model calculation based on mean measured concentration of 7.1 and 0.78 µg/L Anthraquinone in the test solutions and corresponding concentration of14C -residues in the tissue of the exposed oysters predict a bioconcentration factor for Anthraquinone in oysters tissue was independent of the exposure concentration.

3. Continued elimination of14C -residues from oysters, after exposure to both 7.1 and 0.78 µg/L Anthraquinone, was observed throughout the depuration period. Half-life (50% elimination) of the14C residues present in the oysters tissue during steady state (exposure days 1 -14) occur during the firs 24 hours of the depuration period. After 14 days depuration, 93% and 87% elimination of14C -residues present during steady-state had been achieved in oysters exposed to 7.1 and 0.78 µg/L Anthraquinone respectively.