Pentaboron sodium octaoxide

Bioaccumulation: aquatic / sediment

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Qualifier:

no guideline followed

Principles of method if other than guideline:

Samples of water, sediment, particulate organic detritus, filamentous algae, net plankton, aquatic macroinvertebrates and fishes were collected during spring and fall 1987 for chemical determinations of B, Mo and Se. Spring collections were made during the beginning of the irrigation season when flows of agricultural drainwater into the San Joaquin River were high, whereas fall collections were made after most irrigation had ended and flows of drainwater into the river were somewhat lower. Boron concentrations were measured in both water samples and in organisms.

GLP compliance:

not specified

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test medium samples: Water samples were collected weekly from each site
- Sample storage conditions before analysis: Samples were placed in acid-rinsed polyethylene bottles, then acidified with ultrapure nitric acid to pH < 2.0 and chilled on ice for transport to the laboratory. In the laboratory all the samples were stored frozen at -10°C. All biota were sorted from debris and rinsed in site water immediately after collection, then wrapped and double-bagged in polyethylene and chilled on ice for transport.
- Details on sampling and analysis of test organisms and test media samples (e.g. sample preparation, analytical methods): Each water sample was collected within 15 cm of the surface as a composite of three grab samples, then about 500 mL was filtered under pressure through a 0.40 µm polycarbonate membrane. About 500 mL of unfiltered water was also collected from each site. Detrital samples were collected by straining sediments through a 3.2 mm mesh dip net, then hand sorting the remaining materials. Filamentous algae were collected with a 153µm mesh student plankton net. Aquatic macroinvertebrates were collected with 3.2 mm mesh dip nets, 3.0 m x 1.8m (2.0 mm square mesh) common sense seines, and baited Gee minnow traps (crayfish only). Fishes are collected with 3.2 mm mesh dip nets, 5.5 m x 1.8 m (6.4 mm square mesh) bag seines, 30.5 m x 1.8 m (12.7 mm square mesh) beach seines, and backpack fish electroshockers.

Vehicle:

no

Test organisms (species):

other: see details

Details on test organisms:

All organisms and samples have been found in the San Joaquin River.
-Water
-Sediment
-Detritus
-Filamentous algae
-Net plankton
-Chironomid larvae
-Amphipods
-Crayfish
-Mosquitofish
-Bluegill
-Largemouth bass

Route of exposure:

aqueous

Test type:

field study

Water / sediment media type:

natural sediment: freshwater

Hardness:

Hardness in spring varied between 40 and 689 mg/L depending on the sampling site, between 52 and 379 mg/L in the fall

Test temperature:

Temperature in spring varied between 10.4 and 14.8 °C depending on the sampling site, between 13.3 and 21.6 °C in the fall

pH:

pH in spring varied between 6.84 and 7.9 depending on the sampling site, between 7.06 and 8.96 in the fall

Dissolved oxygen:

Dissolved oxygen in spring varied between 6.35 and 10.45 mg/L depending on the sampling site, between 6.92 and 9.43 mg/L in the fall

Nominal and measured concentrations:

Measured boron concentrations in water: between <0.09 and 2.9 µg/mL in spring, between <0.12 and 1.5 µg/mL in fall
Measured boron concentrations in sediment: between <1.8 and 6.9 µg/g (dw) in spring, between <3.2 and 12 µg/g in fall

Type:

BCF

Value:

121 L/kg

Basis:

whole body d.w.

Remarks on result:

other: filamentous algae

Type:

BAF

Value:

23 L/kg

Basis:

whole body d.w.

Remarks on result:

other: plankton

Type:

BAF

Value:

21 L/kg

Basis:

whole body d.w.

Remarks on result:

other: Chironomids

Type:

BAF

Value:

23 L/kg

Basis:

whole body d.w.

Remarks on result:

other: amphipods

Type:

BAF

Value:

13 L/kg

Basis:

whole body d.w.

Remarks on result:

other: crayfish

Type:

BAF

Value:

9 L/kg

Basis:

whole body d.w.

Remarks on result:

other: mosquitofish

Type:

BAF

Value:

8 L/kg

Basis:

whole body d.w.

Remarks on result:

other: bluegill

Type:

BAF

Value:

8 L/kg

Basis:

whole body d.w.

Remarks on result:

other: largemouth bass

Details on results:

The authors concluded that boron concentrations did not progressively increase from lower trophic levels to higher trophic levels.

The concentrations measured in water, organisms and BCF values for the spring and fall 1987 are presented in the tables below. All data are shown, ie measurements above detection limits and measurements below detection limit (= set at the detection limit).

Spring 1987	concentration in organisms (µg/g dw)
water concentration (µg/L)	Detritus	Alga	Plankton	Chironomid	Amphipod	Crayfish	Mosquitofish	Bluegill	Largemouth bass
0.1	47	6.8	6.6	2.4	2.2	3.8	1.3	1.9	1.9
2	170	79	22	16	23	15	5.8	1.4	1.9
0.4	50	14	8.7	6.3	2.2	5.6	2	2	2
1.9	140	44	8.2	14	16	13	3.1	1.9	2
2.9	150	280	46	27	22	23	8.4	7.9	2
0.09	11	6.1	1.1	1.6	2.2	2.2	1.9	2	1.9
0.26	23	6.1	1.6	2.8	3.5	3.1	2.0	2	2

Spring 1987	BCF/BAF (L/kg dw)
water concentration (µg/L)	Detritus	Alga	Plankton	Chironomid	Amphipod	Crayfish	Mosquitofish	Bluegill	Largemouth bass
0.1	470	68	66	24	22	38	13	19	19
2	85	40	11	8	12	8	3	1	1
0.4	125	35	22	16	6	14	5	5	5
1.9	74	23	4	7	8	7	2	1	1
2.9	52	97	16	9	8	8	3	3	1
0.09	122	68	12	18	24	24	21	22	21
0.26	88	23	6	11	13	12	8	8	8

Fall 1987	concentration in organisms (µg/g dw)
water concentration (µg/L)	Detritus	Alga	Plankton	Chironomid	Amphipod	Crayfish	Mosquitofish	Bluegill	Largemouth bass
0.12	19	92		10	7.3	2	1.9	1.9	1.9
1.2	77	59	40	15	15	11	4.3	1.9	1.9
0.41	24	43	17	8.1	7.4	2.4	3.2	2	2
0.94	100	50		20	14	6.7	4.8	1.2	1.9
1.5	190	200	25	19	19	9.6	7.8	1.7	2
0.17	13	200		3.9	7.3	1.2	1.9	1.9	1.9
0.12	10	3.5		3.9	7.9	2.7	2.0	2	2

Fall 1987	BCF/BAF (L/kg dw)
water concentration (µg/L)	Detritus	Alga	Plankton	Chironomid	Amphipod	Crayfish	Mosquitofish	Bluegill	Largemouth bass
0.12	158	767		83	61	17	16	16	16
1.2	64	49	33	13	13	9	4	2	2
0.41	59	105	41	20	18	6	8	5	5
0.94	106	53		21	15	7	5	1	2
1.5	127	133	17	13	13	6	5	1	1
0.17	76	1176		23	43	7	11	11	11
0.12	83	29		33	66	23	17	17	17

Reference 2

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Qualifier:

no guideline followed

Principles of method if other than guideline:

Salt water-acclimated sockeye Oncorhynchus nerka (40.8-58.1g) received a dose of 10 µg/mL boron above background. After a period of 3 weeks, the fish in each tank were killed for determination of boron concentration in gill, liver, kidney, muscle and bone tissue.

GLP compliance:

not specified

Radiolabelling:

no

Vehicle:

no

Test organisms (species):

Oncorhynchus nerka

Details on test organisms:

TEST ORGANISM
- Common name: Sockeye salmon
- Weight at study initiation (mean and range, SD): 43.0 - 58.1 g
- Weight at termination (mean and range, SD): 40.8-65.9 g
- Description of housing/holding area: 80 L fiberglass tanks containing 60 L of solution
- Fish were saltwater-acclimated (method not described)

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: marine

Total exposure / uptake duration:

3 wk

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, fill volume: 80 L fiberglass tanks filled with 60 L solution
- Renewal rate of test solution (frequency/flow rate): 500 ml/min fresh seawater and 2 ml/min borate solution 95% solution replacement in approximately 6h.
- No. of organisms per vessel: 3
- No. of vessels per concentration (replicates): 2
- No. of vessels per control / vehicle control (replicates): 1

Nominal and measured concentrations:

10 µg/mL above background

Reference substance (positive control):

not specified

Type:

BCF

Value:

0.558 L/kg

Basis:

organ w.w.

Remarks:

gill

Remarks on result:

other: BCF reported as mean value of 5 samples

Remarks:

Conc.in environment / dose:10 µg/ml in water; 5.58 µg/g (tissue; wet weight)

Type:

BCF

Value:

0.52 L/kg

Basis:

organ w.w.

Remarks:

liver

Remarks on result:

other: BCF reported as mean value of 5 samples

Remarks:

Conc.in environment / dose:10 µg/mL in water; 5.2 µg/g (tissue; wet weight)

Type:

BCF

Value:

0.725 L/kg

Basis:

organ w.w.

Remarks:

kidney

Remarks on result:

other: BCF reported as mean value of 4 samples

Remarks:

Conc.in environment / dose:10 µg/mL in water; 7.25 µg/g (tissue; wet weight)

Type:

BCF

Value:

3.76 L/kg

Basis:

organ w.w.

Remarks:

muscle

Remarks on result:

other: BCF reported as mean value of 5 samples

Remarks:

Conc.in environment / dose:10 µg/mL in water; 3.76 µg/g (tissue; wet weight)

Type:

BCF

Value:

10.5 L/kg

Basis:

organ w.w.

Remarks:

bones

Remarks on result:

other: BCF reported as mean value of 5 samples

Remarks:

Conc.in environment / dose:10 µg/mL in water; 10.5 µg/g (tissue; wet weight)

The results indicated that boron uptake increased with increasing availability. Retention of boron within body tissues of sockeye salmon after exposure was not investigated and no evidence of active bioaccumulation was observed. The boron levels in tissue of sockeye salmon were not significantly different from test water concentrations.

The boron levels in individual sockeye in control seawater and two boron exposure tanks (after 3 weeks of exposure) containing 10 µg/mL above background are reported herebelow

	µg/g (gill; wet weight)	µg/g (liver; wet weight)	µg/g (kidney; wet weight)	µg/g (muscle; wet weight)	µg/g (bone; wet weight)
Control tank(sample A/B/C)	1.3/1.0/0.3	1.0/0.3	1.0/0.3	0.8/0.6/0.2	4.4/3.1/1.1
Tank 1 - sample A	4.6	4.8	5.8	3.3	9.5
Tank 1 - sample B	6.7	5.6	6.8	4.1	12.0
Tank 1 - sample C	3.5	3.3	4.5	2.0	8.1
Tank 2 - sample A	3.0	3.5	/	1.5	5.9
Tank 2 - sample B	10.1	8.8	11.9	7.9	17.0

Reference 3

Endpoint:

bioaccumulation in aquatic species: fish

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Qualifier:

no guideline followed

Principles of method if other than guideline:

Chinook salmon were placed in aquariums with different kinds of water(well-water, freshwater and brackish water) and effect on survival, growth and whole body concentrations were assessed at different concentrations of boron, molybdenum and selenium. Samples were taken after 30, 60 and 90 days.

GLP compliance:

not specified

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: Samples were taken after 30, 60 and 90 days
- Sampling intervals/frequency for test medium samples: Samples were taken at 15-d intervals
- Sample storage conditions before analysis: Water samples for boron were preserved in 1% HNO3 and tissue samples were stored at -20°C
- Details on sampling and analysis of test organisms and test media samples (e.g. sample preparation, analytical methods):
- Water samples were analyzed directly for boron with an inductively coupled argon plasma spectrophotometer (Jarrel-Ash model 975 AtonComp) equipped with a DEC PDP-8E computer and DECwriter III terminal.
-Tissue samples were lyophilized to a constant weight, homogenized with a commercial blender, placed in Whirl-Pak plastic bags and stored in a desiccator. 1g of sample was placed in a 100-ml acid-cleaned Teflon beaker, and 20 ml of a 1:4 mixture of HClO4 and HNO3 was added. The mixture was swirled gently to wet the tissue completely, covered with a Teflon watch glass, and allowed to predigest at room temperature for 12h. The watch glass was removed and the mixture was placed on a hot plate at low heat until the evolution of dark red gas subsided. The hot plate temperature was then increased until dense white HClO4 fumes began eolving from the solution, after which the sample was heated for an additional 5 min. In samples that appeared to be charring, 5 ml of concentrated HNO3 was added and the samples were heated again until HClO4 fumes were produced. The digestate was transferred to a 125 ml low-density polyethylene bottle and brought to 100 ml by weight with ultrapure water and a final acid matrix of 4% HClO4. Concentrations of boron in tissue digestates were determined by the plasma spectrophotometer as described earlier.

Vehicle:

no

Test organisms (species):

Oncorhynchus tschawytscha

Details on test organisms:

TEST ORGANISM
- Common name: Chinook Salmon
- Source: eyed eggs from the Merced River Fish Facility
- Age at study initiation (mean and range, SD): eggs 2 weeks before hatch for the wel water study ; 0.3g juvenile for the freshwater study ; 2g juveniles for the brackish water study.
- Description of housing/holding area: 20 fish in each of two 11.5 L growth chambers and 60 fish in the 23 L main tank
- Feeding during test
- Food type: Biodiet : a commericial salmon diet
- Amount: ad libitum
- Frequency: ad libitum

ACCLIMATION
- Acclimation period: 2 days

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: freshwater

Total exposure / uptake duration:

90 - 104 d

Hardness:

612 mg total hardness/L well water
371 mg total hardness/L reconstituted water

Test temperature:

12°C

pH:

7.8 well water
7.9 reconstituted water

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 46 L aquaria with 2 x 11.5 L growth chambers for growth determinations and a 23 L main chamber
- Type of flow-through (e.g. peristaltic or proportional diluter): intermittent-flow proportional diluter
- No. of organisms per vessel: 2 x 20 in growth chambers and 60 in main chamber
- No. of vessels per concentration (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: natural fresh water : well water


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconsituted freshwater : high purity water mixed with salts

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Survival was recorded daily and growth was evaluated at 30 days of interval
OTHER TEST CONDITIONS
- Photoperiod: controlled by a timed artificial lighting system to simulate conditions in central California from January to March
- Note that exposures were combinations of Se, Mo and B.

Nominal and measured concentrations:

Nominal exposure concentrations : 0x, 0.25x, 0.5x, 1x, 2x and 4x with 1x being 1,400 µg B/L
Measured concentration well water : 164, 500, 834, 1463, 2692, 5537 µg B/L
Measured concentration reconstituted water : 259, 591, 927, 1628, 3023, 6046 µg B/L
96% spike recoveries in water samples, 92% recovery in tissue samples

Type:

BCF

Value:

< 0.1 L/kg

Basis:

whole body d.w.

Time of plateau:

60 d

Calculation basis:

other: no data

Remarks on result:

other: Conc.in environment / dose:5537 µg B/L in well water; <1.7 µg/g in tissue

Type:

BCF

Value:

< 0.1 L/kg

Basis:

whole body d.w.

Time of plateau:

60 d

Calculation basis:

other: no data

Remarks on result:

other: Conc.in environment / dose:2692 µg//L in well water; <1.7 µg/g in tissue

Type:

BCF

Value:

< 0.1 L/kg

Basis:

whole body d.w.

Time of plateau:

60 d

Calculation basis:

other: no data

Remarks on result:

other: Conc.in environment / dose:3023 µg/L in freshwater; <1.7 µg/g in tissue

Type:

BCF

Value:

< 0.1 L/kg

Basis:

whole body d.w.

Time of plateau:

60 d

Calculation basis:

other: no data

Remarks on result:

other: Conc.in environment / dose:6046 µg/L in freshwater; <1.7 µg/g in tissue

Reference 4

Endpoint:

bioaccumulation in aquatic species, other

Type of information:

experimental study

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Qualifier:

no guideline followed

Principles of method if other than guideline:

Bio-accumulation tests were performed with the marine Pacific oyster Crassostrea gigas at concentrations of 1 µg/mL and 10 µg/mL boron above background levels. After a period of 47 days, boron administration was halted and the animals received only seawater inflow until day 71. Boron tissue concentrations were measured at the start, during the dosing of boron, after the boron dose was stopped.

GLP compliance:

not specified

Radiolabelling:

no

Details on sampling:

- Sampling intervals/frequency for test organisms: after 8, 16, 36, 47, 71 days

Vehicle:

no

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

PREPARATION OF SPIKED WATER
- Test substance was dissolved and solutions were adjusted to the pH of the diluent water

Test organisms (species):

other: Crassostrea gigas

Details on test organisms:

TEST ORGANISM
- Common name: Pacific oysters
- Weight at study initiation (mean and range, SD): 4.0 - 6.29g wet tissue wt
- Description of housing/holding area: 5 oysters per 80l fiberglass tanks containing 60l test solution

Route of exposure:

aqueous

Test type:

flow-through

Water / sediment media type:

natural water: marine

Total exposure / uptake duration:

47 d

Total depuration duration:

24 d

Details on test conditions:

TEST SYSTEM
- Test vessel:
- Material, size, fill volume: 80 L fibreglass tanks containing 60 L of test solution
- Renewal rate of test solution (frequency/flow rate): 500 ml/min fresh seawater and 2.0 ml/min of concentrated borate solution, 95% solution replacement in approximately 6h
- No. of organisms per vessel: 30
- No. of vessels per concentration (replicates): 2
- No. of vessels per control / vehicle control (replicates): 1

Nominal and measured concentrations:

1 µg B/ml and 10 µg B/ml above background

Reference substance (positive control):

not specified

Type:

BCF

Value:

0.7 - 1.4 L/kg

Oysters (C gigas) were exposed to 1 µg B/ml and 10 µg B/ml above background for 47 days.At the highest exposure concentration, boron tissue concentrations were 13 µg B/g by day 36.By day 47 these concentrations decreased to 11µg B/g. After cessation of exposure, tissue concentrations returned to background levels (3.67 -4.01 µg B/g ) within 25 days. Thompson et al did not calculate BCF values. Based on the data presented BCF values can be calculated from 0.7 to1.4 L/kg. Low BCFs and reduction of tissue concentrations during exposure suggests regulation and that boron will not accumulate to high concentrations.

Additional information

Bioconcentration factors of <0.1 to 10.5 L/kg have been reported from laboratory tests of fish and oysters (Hamilton and Wiedmeyer, 1990; Thompson et al. 1976). Saiki et al. (1993) measured boron levels in aquatic food chains and observed the highest concentrations of boron in detritus and filamentous algae. Invertebrates and fish had lower concentrations, indicating that bioaccumulation was not occurring. Based on these data, boron does not bioaccumulate in the aquatic environment. 

Please also refer to the read-across statement section 13.