Propargite

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

key study

Study period:

22nd September 1987 to 10th November 1987

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Study performed in accordance with in-house protocol considered to be equivalent or similar to current guideline, possibly with incomplete reporting or methodological deficiencies, which do not affect the quality of the relevant results.

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 305 E (Bioaccumulation: Flow-through Fish Test)

Deviations:

yes

Remarks:

(95% C.I. were not calculated)

GLP compliance:

yes

Radiolabelling:

yes

Details on sampling:

To monitor the concentration of 14C-residues in water of the treatment and control aquaria, 5 mL water samples were collected on days 1, 2 and 3 of equilibration and days 0, 1, 3, 7, 10, 14, 21, 28 and 35 of exposure and days 1, 3, 7, 10 and 14 of depuration. Each sample was counted by LSC.

In order to quantify the accumulation and elimination of 14C-residues in the edible and non-edible tissue of bluegill, five fish were collected from the treatment aquarium, eviscerated and filleted on days 1, 3, 7, 10, 14, 21, 28 and 35 of exposure and days 1, 3, 7, 10 and 14 of depuration. Five control fish were removed, eviscerated and filleted on day 28 of exposure and day 14 of depuration to quantify background levels of 14C-residues in fish tissue. Five unexposed fish were eviscerated and filleted on day 0 of exposure. Each sample was oxidised and counted by LSC.

Vehicle:

yes

Details on preparation of test solutions, spiked fish food or sediment:

PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: 75.8953 mg non-radiolabelled test material was added to a 250 mL volumetric flask containing acetone. 37 mg of 14C-Omite was then added and the flask bought up to volume for a 413.33 µg/mL stock solution.
- Chemical name of vehicle (organic solvent, emulsifier or dispersant): acetone

Test organisms (species):

Lepomis macrochirus

Details on test organisms:

TEST ORGANISM
- Common name: bluegill sunfish
- Source: Springborn Life Sciences, Inc., Wareham, Massachusetts, USA
- Length at study initiation (length definition, mean, range and SD): 58 (50-68) mm
- Weight at study initiation (mean and range, SD): 2.6 (1.67-4.27) g
- Feeding during test
- Food type: dry pelleted food
- Amount: equal to 2 % of the mean organism body weight
- Frequency: daily

ACCLIMATION
- Acclimation period: 14 days
- Type and amount of food: dry pelleted food ad libitum
- Feeding frequency: daily except for 48 hours prior to test

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

35 d

Total depuration duration:

14 d

Hardness:

26-33 mg CaCO3/L

Test temperature:

15-18 ºC

pH:

6.5-7.4

Dissolved oxygen:

5.8-10.3 mg/L

Details on test conditions:

TEST SYSTEM
- Test vessel: aquaria
- Material, size, headspace, fill volume: 76 x 30 x 40 cm aquaria; water depth 25.4 cm; water volume approximately 75 litres
- Type of flow-through: proportional diluter
- Renewal rate of test solution (frequency/flow rate): 90 % volume replacement per each 9 hour period
- No. of organisms per vessel: 175
- No. of vessels per concentration (replicates): 1
- No. of vessels per control / vehicle control (replicates): 1

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: well water
- Alkalinity: 29-33 mg/L
- Conductance: 110-120 µmhos/cm
- Total hardness: 30-36 mg/L

OTHER TEST CONDITIONS
- Adjustment of pH:
- Photoperiod: approximately 16 hours light
- Light intensity: 4-7 hectolux at the water surface

Nominal and measured concentrations:

3.1 µg/L (nominal 14C-Omite)

Reference substance (positive control):

no

Details on estimation of bioconcentration:

BASIS FOR CALCULATION OF BCF
- Dividing the mean measured equilibrium 14C-tissue concentration for each tissue type by the mean measured water concentration for the entire exposure period.
- Alternatively, by utilising the ratio of the uptake constant to the depuration constant as follows:

The depuration constant (Kd) was obtained by linear regression of log tissue concentration vs. depuration time during the depuration period. The uptake constant (Ku) was obtained using the following equation:

Ku = ((dC/dt + KdC) / Cw)

where:
Kd = depuration constant (per day)
C = tissue concentration at time t (mg/kg)
Cw = water concentration at time t (mg/L)
dC/dt = slope of the tangent to the uptake curve at time t (mg/kg per day)

BCF = Ku/Kd

Key result

Type:

BCF

Value:

260 dimensionless

Basis:

edible fraction

Time of plateau:

7 d

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:3.1 µg/L

Key result

Type:

BCF

Value:

727 dimensionless

Basis:

edible fraction

Time of plateau:

7 d

Calculation basis:

kinetic

Remarks on result:

other: Conc.in environment / dose:3.1 µg/L

Key result

Type:

BCF

Value:

1 550 dimensionless

Basis:

non-edible fraction

Time of plateau:

10 d

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:3.1 µg/L

Key result

Type:

BCF

Value:

3 760 dimensionless

Basis:

non-edible fraction

Time of plateau:

10 d

Calculation basis:

kinetic

Remarks on result:

other: Conc.in environment / dose:3.1 µg/L

Key result

Type:

BCF

Value:

775 dimensionless

Basis:

other: whole body

Calculation basis:

steady state

Remarks on result:

other: Conc.in environment / dose:3.1 µg/L

Key result

Type:

BCF

Value:

1 840 dimensionless

Basis:

other: whole body

Calculation basis:

kinetic

Remarks on result:

other: Conc.in environment / dose:3.1 µg/L

Details on results:

Analysis of tissues in the depuration phase indicated that there was a continuous elimination from the bodies of the test animals with the DT50 for depuration estimated to be between 3 and 7 days. By day 14, 82, 91 and 89 % depuration was recorded for edible tissue, non-edible tissue and on a whole body basis, respectively.

Of the accumulated 14C residue, 51 % was found to be extractable and 46 % non-extractable.

Table 1: Measured ¹⁴C-residue concentrations during 35 days of continuous aqueous exposure and during an additional 14 day depuration phase

		^14C-tissue residue concentration (µg/kg)
Day	Water concentration (µg/L)	Edible	Non-edible	Whole body
Exposure
0	3.3 (0.2)	-	-	-
1	7.8 (3.5)	270 (42)	2100 (380)	1000 (120)
3	2.3 (0.1)	500 (38)	4800 (270)	2100 (180)
7	3.5 (0.1)	730 (120)	5200 (660)	2400 (330)
10	6.0 (2.4)	1100 (400)	6400 (930)	3000 (430)
14	3.8 (0.1)	1100 (290)	6800 (1000)	3500 (350)
21	3.5 (0.5)	1300 (840)	5300 (1900)	3000 (360)
28	2.6 (0.6)	960 (130)	5400 (780)	2700 (350)
35	2.4 (1.5)	1000 (58)	7300 (320)	3400 (200)
Depuration
1	<0.49	850 (78)	8300 (1400)	3700 (600)
3	<0.49	630 (90)	5800 (1600)	2600 (640)
7	<0.41	340 (60)	1500 (160)	810 (83)
10	<0.41	230 (24)	950 (260)	500 (110)
14	<0.41	190 (24)	640 (140)	360 (61)

Validity criteria fulfilled:

not specified

Conclusions:

Under the conditions of the test, the whole body BCF of propargite in bluegill sunfish was calculated to be 775 (250 in edible tissues and 1550 in non-edible tissues). Following removal to clean water, the DT50 for depuration was estimated to be between 3 and 7 days. By day 14, 82, 91 and 89 % depuration was recorded for edible tissue, non-edible tissue and on a whole body basis, respectively.

Executive summary:

Bluegill were continuously exposed to a nominal concentration of 3.1 µg/L of ¹⁴C-Omite in well water for 35 days after which approximately 35 fish were transferred to flowing uncontaminated water for a 14 day depuration period. Radiometric analyses of the water and selected fish tissues revealed the following:

1. The mean concentration of aqueous ¹⁴C-residues in the treated system throughout the 35 day exposure period was 4.0 ± 2.0 µg/L. Concentration of ¹⁴C-residues present in the water of the depuration aquarium remained ≤ 0.49 µg/L throughout the 14 day depuration period.

2. The concentration of ¹⁴C-residues in the edible tissue of bluegill exposed to ¹⁴C-Omite reached steady state by day 7. The mean equilibrium bioconcentration factor for ¹⁴C-Omite in the edible tissue of bluegill during the 25 days of exposure was 260X.

3. The concentration of ¹⁴C-residues in the non-edible tissue of the exposed bluegill reached steady state by day 10. The mean equilibrium bioconcentration factor for ¹⁴C-Omite in the non-edible tissue of bluegill was 1550X.

4. The pattern of accumulation of ¹⁴C-residues calculated in the whole body of bluegill exposed to ¹⁴C-Omite was similar to that observed for the non-edible tissue. The mean equilibrium bioconcentration factor for ¹⁴C-Omite in the whole body of bluegill was 775X.

5. Continuous elimination of ¹⁴C-residues from the selected tissue portions of bluegill and consequently on a whole fish basis was observed during the depuration period. Half-life of the ¹⁴C-residues present in the edible tissue portion of bluegill on the last day of exposure occurred between the third and seventh day of depuration for the ¹⁴C-residues in the edible, non-edible and whole body tissues. By day 14 of the depuration period, 82, 91 and 89 % of the ¹⁴C-residues present on the last day of exposure had been eliminated in the edible, non-edible and whole fish tissues, respectively.

6. The percentage of extractable ¹⁴C-residues accumulated in the edible tissue was found to be 11 % with methanol, 40 % with hexane and 46 % was non-extractable with either solvent.

Description of key information

BCF 1840 (whole body, kinetic); study conducted in accordance with in-house protocol considered to be equivalent or similar to OECD 305E; Suprenant, 1988

Key value for chemical safety assessment

BCF (aquatic species):

1 840 dimensionless

Additional information

The bioaccumulation of propargite was determined in two bluegill sunfish studies. They key study was performed to GLP study with an in-house protocol which is considered to be similar or equivalent to OECD 305E. The supporting study was a non-GLP study and was not performed to an appropriate guideline.

In the key study, bluegill sunfish were continuously exposed to a nominal concentration of 3.1 µg/L of ¹⁴C-Omite for 35 days after which approximately 35 fish were transferred to flowing uncontaminated water for a 14 day depuration period. Radiometric analyses of the water and selected fish tissues revealed the following: the concentration of ¹⁴C-residues in edible tissue reached a steady state by day 7 and the mean equilibrium bioconcentration factor in edible tissue was 260X; the concentration of ¹⁴C-residues in non-edible tissue reached a steady state by day 10 and the mean equilibrium bioconcentration factor in non-edible tissue was 1550X; the pattern of accumulation calculated in the whole body was similar to that observed for the non-edible tissue and the mean equilibrium bioconcentration factor in the whole body was 775X (steady state) and 1840X (kinetic); by day 14 of the depuration period, 82, 91 and 89 % of the¹⁴C-residues present on the last day of exposure had been eliminated in the edible, non-edible and whole fish tissues, respectively and the percentage of extractable¹⁴C-residues accumulated in the edible tissue was found to be 11 % with methanol, 40 % with hexane and 46 % non-extractable with either solvent.

In the supporting study, bluegill sunfish were continuously exposed to¹⁴C-Omite at a nominal concentration of 0.025 mg/L for 35 days and the fish remaining were then transferred to an uncontaminated system for 21 days. Fish exposed to 0.025 mg/L for 35 days looked normal, fed readily and appeared to be in excellent physical condition. During the exposure period, bluegill concentrated residues in muscle tissue to a level 165x the level to which they were exposed in water and residues measured in the non-edible portions were approximately 10x the residue in the edible portion. Within 14 days of transfer to uncontaminated water, 70 % of the¹⁴C-residues present in the edible portion and 90 % of the¹⁴C-residues in the non-edible portion were eliminated.