Registration Dossier

Ecotoxicological information

Long-term toxicity to fish

Currently viewing:

Administrative data

Link to relevant study record(s)

Referenceopen allclose all

Endpoint:
fish, juvenile growth test
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well performed study. Effect concentrations based on measured Se concentrations.
Reason / purpose for cross-reference:
reference to same study
Qualifier:
no guideline followed
Principles of method if other than guideline:
Juvenile fish were exposed for 60 days to a control or one of 5 waterborne exposure concentrations in a flow-through system. A 6:1 ratio (Se) of sodium selenate to sodium selenite was used. Survival was monitored.
GLP compliance:
not specified
Analytical monitoring:
yes
Details on sampling:
- For total Se analysis, 200 mL of exposure water were collected from midwater of each treatment on day 3 and every 2 weeks thereafter, acidified with 1 mL of HCl, and frozen.
- Samples for Se tissue residue analysis were taken on days 30 and 60.
Vehicle:
no
Details on test solutions:
PREPARATION AND APPLICATION OF TEST SOLUTION (especially for difficult test substances)
- Method: Stock solutions prepared and diluted to test concentration
Test organisms (species):
Lepomis macrochirus
Details on test organisms:
TEST ORGANISM
- Common name: Bluegill sunfish
- Source: Mammoth Springs National Fish Hatchery, Mammoth Springs, AR.
- Age at study initiation (mean and range, SD): 5 months
- Weight at study initiation (mean and range, SD): 0.3 g

FEEDING DURING TEST
- Food type: Rangens commercial diet
- Amount: ad libitum
- Frequency: 3 times daily

ACCLIMATION
- Acclimation period: 5 days
- Conditions same as during test
Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
60 d
Hardness:
137-143 mg CaCO3/L
Test temperature:
25°C
pH:
7.9-8.3
Dissolved oxygen:
not reported
Salinity:
not applicable
Nominal and measured concentrations:
Measured: Control + 0.16-0.33-0.64-1.12-2.8 mg Se/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 79x32x30.5 cm glass aquaria, fill volume 51.1 L, aquaria divided into two 8.7 L chambers (for growth observations) and one 31.1 L chamber (for behavioral observations and tissue residue measurements)
- Type (delete if not applicable): open
- Aeration: from flow
- Type of flow-through (e.g. peristaltic or proportional diluter): Mount and Brungs proportional diluter
- Renewal rate of test solution (frequency/flow rate): 1.9 volume replacements/day
- No. of organisms per vessel: 10
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water
- Alkalinity: 69-72 mg CaCO3/L
- Sulfate = 66-94 mg/L

OTHER TEST CONDITIONS
- Photoperiod: 16L:8D

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality, every 24 h
Duration:
60 d
Dose descriptor:
NOEC
Effect conc.:
330 µg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Remarks:
Se
Basis for effect:
mortality
Duration:
60 d
Dose descriptor:
LOEC
Effect conc.:
640 µg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Remarks:
Se
Basis for effect:
mortality
Duration:
60 d
Dose descriptor:
NOEC
Effect conc.:
4 other: mg/kg dw whole body
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Remarks:
Se
Basis for effect:
mortality
Duration:
60 d
Dose descriptor:
LOEC
Effect conc.:
5 other: mg/kg dw whole body
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Remarks:
Se
Basis for effect:
mortality
Reported statistics and error estimates:
ANOVA and Fisher's least significant difference test.
Validity criteria fulfilled:
yes
Conclusions:
In this reliable (Klimisch 2) study, juvenile bluegill sunfish (Lepomis macrochirus) were exposed for 60 days to a control or one of 5 waterborne exposure concentrations in a flow-through system. A 1:1 ratio (Se) of sodium selenate to sodium selenite was used as test substance mixture. The waterborne NOEC and LOEC for the endpoint mortality were determined to be 0.33 and 0.64 mg Se/L, respectively. When based on whole body concentrations, the NOEC and LOEC are 4 and 5 mg Se/kg dw, respectively.
Endpoint:
fish life cycle toxicity
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Well performed study. This study was conducted in outdoor experimental streams. However, exposure was fairly constant. Se concentrations were measured and throughout the study similar to nominal concentrations. Exposure was both via water and (naturally present) diet. Although outdoor experimental streams do not ascertain entirely 'controlled' exposure conditions, this long-term study offers useful data for hazard assessment purposes.
Reason / purpose for cross-reference:
reference to same study
Qualifier:
no guideline available
Principles of method if other than guideline:
Year long study investigating the effect of selenium on pre-spawning growth and mortality of adult bluegills in outdoor experimental streams as well as on hatching success, larval survival and prevalence of larval deformities of progeny of the exposed fish, exposed to similar selenium concentrations as the parent fish. Exposure was via the water (and, because of the presence of natural food, also partly via the diet).
GLP compliance:
not specified
Analytical monitoring:
yes
Details on sampling:
Water samples for verification of selenium concentrations were taken twice weekly.
Fish samples for determination of selenium residues in fish and fish organs were taken after 258 and 365 days.
Vehicle:
no
Details on test solutions:
see test conditions
Test organisms (species):
Lepomis macrochirus
Details on test organisms:
TEST ORGANISM
- Common name: Bluegill sunfish
- Source: adults obtained from a south-central Minnesota farm pond
- Age at start of testing: 3-4 years old (adults)
- Average initial length = 170.8 mm
- Average initial weight = 96.0 g
- Feeding during the test: fish were allowed to feed on the stable community of plants and invertebrates present in the experimental streams
Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
356 d
Remarks on exposure duration:
total exposure duration of adults
Hardness:
Water hardness = 179 mg CaCO3/L.
Test temperature:
Temperature = 4.6°C (winter), 26.4°C (spawning season).
pH:
8.0
Dissolved oxygen:
Dissolved oxygen = 9.5 (winter-spring), 3.6 and 8.1 (spawning season, early morning and mid-afternoon, respectively).
Salinity:
not applicable
Nominal and measured concentrations:
Nominal: Control + 0.01-0.03 mg/L.
Measured: Control (< 1 µg Se/L) + 10.0 or 9.9 + 30.1 or 30.0 µg Se/L (depending on the replicate).
Details on test conditions:
TEST SYSTEM
- Test vessel: outdoor 520-m experimental stream constructed in an alternating pool-riffle design
- Type (delete if not applicable): open
- Aeration: from flow
- Type of flow-through (e.g. peristaltic or proportional diluter): continuously flowing - sodium selenite was metered directly into the water distribution lines with Liquid Metronics, Inc. (Madison, WI) pumps before the water entered the stream channels - total water flow and metering pumps were checked daily - new stock solutions were prepared usually every 3 to 4 days - dosing began approximately 25 weeks before the bluegills were stocked and continued through the duration of the study
- Renewal rate of test solution (frequency/flow rate): 150 gal/min (November-March) to 200 gal/min (other seasons)
- No. of vessels per concentration (replicates): 2
- No. of vessels per control (replicates): 2
- No of organisms per replicate: 122

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Winter: equal parts of well water and Mississippi river water. Summer: Mississippi river water.
- Alkalinity = 160 mg CaCO3/L
- Specific conductivity = 339 µmhos/cm

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): pre-spawning growth and mortality (after 258 days of exposure), mortality during 98 days from the start of spawning (between day 258 and 365 of exposure)
Duration:
258 d
Dose descriptor:
NOEC
Effect conc.:
10 µg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Se
Basis for effect:
adult mortality
Remarks:
during pre-spawning period
Duration:
258 d
Dose descriptor:
LOEC
Effect conc.:
30 µg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Se
Basis for effect:
adult mortality
Remarks:
during pre-spawning period
Details on results:
Pre-spawning growth:
258-d NOEC < 10 µg Se/L
258-d LOEC = 10 µg Se/L
Mortality between start of spawning period (day 258) and end of testing (day 365):
NOEC < 10 µg Se/L
LOEC = 10 µg Se/L
Reported statistics and error estimates:
ANOVA and protected least-significant-difference method.


At 258 days, adult fish were found to have 4.4 µg Se/g wet weight in the ovaries, and at 356 days, adult fish had 4.5 µg Se/g wet weight in the ovaries.

Validity criteria fulfilled:
not applicable
Conclusions:
Reliable (Klimisch 2) study on the toxicity of selenite to bluegills (Lepomis macrochirus). Adult (3-4 year-old) bluegills were exposed to selenite in outdoor experimental streams dosed with sodium selenite in the water. Effects of selenite were evaluated by monitoring growth and mortality during the pre-spawning period (258 days) and mortality from the onset of spawning (day 258) until the end of the study (day 365). The lowest unbound NOEC and LOEC were obtained for pre-spawning mortality and were 10 and 30 µg Se/L, respectively. During the spawning period eggs and larvae were gathered for further study. The effects of selenite on these early-life stages are described in the other endpoint study record on this study.
Endpoint:
fish, juvenile growth test
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well performed study. Effect concentrations based on measured selenium concentrations.
Qualifier:
no guideline followed
Principles of method if other than guideline:
Salmo gairdneri (rainbow trout) fry were exposed to waterborne selenium as sodium selenite for a period of 90 days under flow-through conditions using a proportional diluter. Five concentrations and a control were tested. Test concentrations were analytically verified.
GLP compliance:
not specified
Analytical monitoring:
yes
Details on sampling:
Water samples were taken from all treatments, frequency not stated.
Vehicle:
no
Details on test solutions:
see test conditions
Test organisms (species):
Oncorhynchus mykiss (previous name: Salmo gairdneri)
Details on test organisms:
TEST ORGANISM
- Common name: rainbow trout
- Source: no data
- Length at study initiation: 21.7 mm
- Weight at study initiation: 75 mg
- Fish were fed a commercial diet supplemented with live nauplii of brine shrimp (ad libitum) for the first 30 days of the study.
Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
90 d
Hardness:
272 mg CaCO3/L
Test temperature:
12 +/- 1 °C
pH:
7.4
Dissolved oxygen:
237 mg CaCO3/L
Nominal and measured concentrations:
Measured concentrations: control, 7.8, 12.4, 21.0, 47.2 and 99.5 ug/L
Details on test conditions:
TEST SYSTEM
- Type of flow-through: proportional diluter
- No. of organisms per vessel: 20 fry
- No. of vessels per concentration (replicates): 2

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: well water
- Dilution water parameters: Well water was characterized by pH 7.4, alkalinity 237 mg/L as CaCO3 , hardness 272 mg/L as CaCO3 and selenium < 0.4 ug/L.

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): mortality, length and body weight
Duration:
90 d
Dose descriptor:
NOEC
Effect conc.:
21 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
element
Remarks:
Se
Basis for effect:
mortality
Duration:
90 d
Dose descriptor:
LOEC
Effect conc.:
47.2 µg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Remarks:
Se
Basis for effect:
mortality
Duration:
90 d
Dose descriptor:
NOEC
Effect conc.:
47.2 µg/L
Nominal / measured:
meas. (arithm. mean)
Conc. based on:
element
Remarks:
Se
Basis for effect:
length
Remarks:
and body weight
Duration:
90 d
Dose descriptor:
LOEC
Effect conc.:
99.5 µg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Remarks:
Se
Basis for effect:
length
Remarks:
and body weight
Reported statistics and error estimates:
Split plot in time analysis of variance + Least Significant Difference test.
Validity criteria fulfilled:
yes
Conclusions:
Reliable (Klimisch 2) study in which Salmo gairdneri (rainbow trout) fry were exposed to selenium as sodium selenite for a period of 90 days under flow-through conditions using a proportional diluter. Five concentrations and a control were tested. Test concentrations were analytically verified. The most sensitive endpoint investigated was mortality with a 90-day NOEC and LOEC of 21 and 47.2 µg Se/L, respectively.
Endpoint:
fish short-term toxicity test on embryo and sac-fry stages
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well performed study. Effect concentrations based on measured Se concentrations.
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 210 (Fish, Early-Life Stage Toxicity Test)
GLP compliance:
no
Analytical monitoring:
yes
Details on sampling:
- Samples were drawn into 15 mL tubes and acidified with 1 drop 1.0 N HNO3 for preservation.
- Frequency: three times weekly
Vehicle:
no
Details on test solutions:
Concentated stock solutions made. Aliquots then diluted to tested concentrations.
Test organisms (species):
Pimephales promelas
Details on test organisms:
TEST ORGANISM
- Common name: Fathead minnows
- Strain: N/A
- Source: obtained from a hatchery maintained in the laboratory (original source = Duluth-Newtown laboratory)
- Age at study initiation (mean and range, SD): 16- to 40-h old viable eggs
- Feeding during test: released fry were fed brine shrimp nauplii 3-5 times daily until the end of testing - feeding was stopped 24 h before finalization of the test
Test type:
flow-through
Water media type:
freshwater
Limit test:
no
Total exposure duration:
28 d
Remarks on exposure duration:
post-hatch
Hardness:
Hard well water - iron removed
Test temperature:
Average temperature = 25.4°C.
pH:
Average pH = 8.16.
Dissolved oxygen:
Average dissolved oxygen = 6.97 mg/L.
Salinity:
not applicable
Nominal and measured concentrations:
Control + 0.023-0.043-0.083-0.153-0.303-0.593 mg Se/L (measured)
Details on test conditions:
TEST SYSTEM
- Test vessel: 5.1-L glass aquaria containing 5 L of test solution
- At the start of testing, eggs were placed into hatching baskets (20 eggs per basket) and randomly assigned to test chambers attached to an oscillating hatching basket device
- At the completion of hatching at most ten fry of normal development were taken from their baskets and released to the aquaria
- Type (delete if not applicable): open
- Aeration: from flow
- Type of flow-through (e.g. peristaltic or proportional diluter): proportional
- Renewal rate of test solution (frequency/flow rate): 95% turn-over time = 5.8 h in 5.1-L aquaria
- No. of fertilized eggs/embryos per vessel: 20 eggs per hatching basket - several hatching baskets per aquarium - later on 10 fry per aquarium
- No. of vessels per concentration (replicates):4
- No. of vessels per control (replicates):4

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: Hard water from a well tapping the Jordan sandstone stratum underlying the Minneapolis-St. Paul metropolitan area. Iron was catalytically removed (0.1 mg/L).
- Alkalinity = 230 mg CaCO3/L

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : Mortality and growth (length and weight)
Duration:
28 d
Dose descriptor:
NOEC
Effect conc.:
83 µg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Remarks:
Se
Basis for effect:
mortality
Remarks:
and growth
Remarks on result:
other: 28-d post-hatch, exposed from 16-40 h after fertilization
Duration:
28 d
Dose descriptor:
LOEC
Effect conc.:
153 µg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Remarks:
Se
Basis for effect:
mortality
Remarks:
and growth
Remarks on result:
other: 28-d post-hatch, exposed from 16-40 h after fertilization
Details on results:
The 28-d NOEC and LOEC based on growth data were identical to those based on mortality data.
No significant effect on hatchability (100% hatchability at highest test concentration of 0.593 mg/L). Idem for hatched fry lengths. The % abnormal fry increased from 9% in the control to 23% at 0.023 mg/L and was only 14% at 0.593 mg/L. It was not indicated whether the % abnormal fry at each concentration was significantly different from the control or not.
Reported statistics and error estimates:
Comparison by one-way ANOVA with treatment differences separated by Dunnett's procedure.

Validity criteria fulfilled:
yes
Conclusions:
Reliable (Klimisch 2) study on the toxicity of selenious acid to fathead minnow (Pimephales promelas) early-life stages. Tests were started with eggs of 16-40 h after fertilization and lasted until 28 days post-hatch. Mortality as well as growth (length and weight) of hatched larvae were monitored. The 28-d NOEC and LOEC for both mortality and growth (length) were found to be 83 and 153 µg Se/L, respectively. No significant adverse effect was observed on hatchability and length of freshly hatched fry.
Endpoint:
fish short-term toxicity test on embryo and sac-fry stages
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well performed study. Selenium concentrations were measured but nominal concentrations were used since measured concentrations deviated < 5% of nominal concentrations. No statistics used/reported but NOEC and LOEC values were clear.
Qualifier:
no guideline followed
Principles of method if other than guideline:
Effects of waterborne selenium dioxide on zebra fish embryos exposed from 1, 2.5, 7, and 27 h after fertilization and larvae exposed from 2-18 h post-hatch. Larvae were observed until 10 days post-hatch. Hatchability, embryo mortality, and larval mortality after hatch were monitored.
GLP compliance:
not specified
Analytical monitoring:
yes
Details on sampling:
Water samples were taken for Se analysis, frequency not reported.
Vehicle:
no
Details on test solutions:
see test conditions
Test organisms (species):
Danio rerio (previous name: Brachydanio rerio)
Details on test organisms:
TEST ORGANISM
- Common name: zebrafish
- Age: eggs were used of 1 h after fertilization (2-8 cell ovum), 2.5 h (late blastula), 7 h (blastoderm enveloping yolk), and 27 h (initiation of heart beat) - larvae were used of 2-18 h post-hatch
- Source: eggs from females reared in the laboratory
- Procedures for breeding and maintaining zebrafish have been described by Niimi and LaHam, 1974).
- No feeding of larvae during experiments.

METHOD FOR PREPARATION AND COLLECTION OF FERTILIZED EGGS
- Females were bred at 5-10 day intervals to ensure low embryo mortality and uniform hatching rates.
- Following spawning, the eggs were examined and the unfertilized and abnormally developing eggs removed.
Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
10 d
Remarks on exposure duration:
up to 10 days post-hatch
Hardness:
45-50 mg CaCO3/L
Test temperature:
26 °C
pH:
7.0
Dissolved oxygen:
6.6-6.9 mg/L
Salinity:
not applicable
Nominal and measured concentrations:
Nominal concentrations: Control + 1, 3, 5 and 10 mg/L (less than 5% of the selenium in solution at each concentration was either lost or taken up by the embryos and larvae).
Details on test conditions:
TEST SYSTEM
- Test vessel: Petri dishes, 60x15 mm, with aluminium covers
- Renewal rate of test solution: daily
- No. of fertilized eggs/embryos per vessel: 50
- No. of vessels per concentration (replicates): 10
- No. of vessels per control (replicates): 10

TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: reconstituted water (passing domestic water through an activated charcoal filter, a mixed-bed demineralizer, and a glass wool filter)

EFFECT PARAMETERS MEASURED (with observation intervals if applicable): hatchability, embryo mortality, larval mortality up to 10 days post-hatch
Dose descriptor:
NOEC
Effect conc.:
1 000 µg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Se
Basis for effect:
other: larval mortality up to 10 d post-hatch
Remarks on result:
other: Exposure from 1-27 hour post-fertilization or 2-18 h post-hatch to 10 days post-hatch.
Details on results:
LOEC for hatchability and embryo mortality was > 10 mg Se/L.
Reported statistics and error estimates:
none

Less than 5% of the selenium in solution at each concentration was either lost or taken up by the embryos.

Validity criteria fulfilled:
yes
Conclusions:
Effects of waterborne selenium dioxide on zebra fish embryos exposed from 1, 2.5, 7, and 27 h after fertilization and larvae exposed from 2-18 h post-hatch. Larvae were observed until 10 days post-hatch. Hatchability, embryo mortality, and larval mortality after hatch were monitored. In all experiments, the NOEC and LOEC for larval mortality after hatch were 1 and 3 mg Se/L, respectively. No significant effects were observed on hatchability and embryo mortality at the highest exposure concentration tested (i.e., 10 mg Se/L).
Endpoint:
fish, juvenile growth test
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Qualifier:
no guideline followed
Principles of method if other than guideline:
- Principle of test: The growth of juvenile Pagrus major exposed for 4 weeks to five different waterborne selenium concentration was determined .
- Short description of test conditions: Selenium exposure took place in 20 L glass tanks containing 6 fish per treatment group in triplicates. Sodium selenite solution was dissolved in the respective glass tanks. The selenium concentrations in the glass tanks were 0, 50, 100, 200, and 400mg/L.
- Parameters analysed / observed: The weight and length of P. major was measured just before exposure, at 2 weeks, and at 4 weeks.
GLP compliance:
not specified
Remarks:
This study was not performed for the purpose of fulfilling REACH requirements; results were identified in a scientific journal.
Specific details on test material used for the study:
Supplier: Sigma, St. Louis, MO, USA
Analytical monitoring:
yes
Details on sampling:
At the end of each period (at 2 and 4 weeks), fish were anesthetized in buffered 3-aminobenzoic acid ethyl ester methanesulfonate (Sigma Chemical, St. Louis, MO), and length and weight were measured.
Vehicle:
no
Test organisms (species):
other: Pagrus major
Details on test organisms:
TEST ORGANISM
- Common name: red sea bream
- Source: ocal fish farm in Tongyeong, Korea.
- Length at study initiation (length definition, mean, range and SD): 15.8 +- 1.6 cm
- Weight at study initiation (mean and range, SD): 90.4 +- 4.7 g
- Food type: commercial diet (Woosungfeed, Daejeon City, Korea)
- Frequency: twice daily

ACCLIMATION
- Acclimation period: 2 weeks
- Acclimation conditions (same as test or not): same as test
- Type and amount of food: same as test
- Feeding frequency during acclimation: twice daily
Test type:
static
Water media type:
saltwater
Limit test:
no
Total exposure duration:
4 wk
Test temperature:
21 +- 1 °C
pH:
8.1 +- 0.5
Dissolved oxygen:
7.1 +- 0.3
Salinity:
33.5 +- 0.6
Nominal and measured concentrations:
0, 50, 100, 200, and 400 µg/L
Details on test conditions:
TEST SYSTEM
- Test vessel: 20 L glass tanks
- Renewal rate of test solution (frequency/flow rate): once every two days
- No. of organisms per vessel: 6
- No. of vessels per concentration (replicates): 3
- No. of vessels per control (replicates): 3

TEST MEDIUM / WATER PARAMETERS
- Chemical oxygen demand (mg/l): 1.13 +- 0.1
- Ammonia (µg/L): 12.5 +- 0.7
- Nitrite (µg/L): 1.3 +- 0.3
- Nitrate (µg/L): 11.48 +- 1.0

OTHER TEST CONDITIONS
- Photoperiod: 12-h:12-h light/ dark cycle

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : weight and length at day 0, 14 and 28
Duration:
4 wk
Dose descriptor:
NOEC
Effect conc.:
25 µg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Se
Basis for effect:
growth rate
Remarks:
daily length gain
Remarks on result:
other: approximately 20% effect at lowest dose tested, NOEC = lowest dose/2
Duration:
4 wk
Dose descriptor:
NOEC
Effect conc.:
100 µg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Se
Basis for effect:
weight
Remarks:
daily weight gain
Duration:
4 wk
Dose descriptor:
LOEC
Effect conc.:
50 µg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Se
Basis for effect:
growth rate
Remarks:
daily length gain
Duration:
4 wk
Dose descriptor:
LOEC
Effect conc.:
200 µg/L
Nominal / measured:
nominal
Conc. based on:
element
Remarks:
Se
Basis for effect:
weight
Remarks:
daily weight gain
Details on results:
No mortality was observed for the exposure periods.
The major hematological findings were significant decreases in RBC count and Ht value in P. major exposed over 100mg/L compared with the control group and 50mg/L exposure at 2 weeks and 4 weeks. The Hb concentration following selenium exposure for 4 weeks was considerably decreased at 100 mg/L after 4 weeks.
Conclusions:
Reliable (Klimisch 2) study on the toxicity of selenite to red sea breams (Pagrus major). Fish were exposed for 4 weeks to selenium via the water. Toxicity was evaluated by monitoring body weight and length. The NOEC for growth and body weight gain was 50 and 100 µg/L, respectively.

Description of key information

Reliable chronic toxicity data for fish vary between 10 and 1000 µg Se/L.

The most critical waterborne NOEC for freshwater fish is a 258-d NOEC of 10 µg Se/L for pre-spawning mortality of bluegills (Lepomis macrochirus) obtained from a study with Na2SeO3.

The most critical NOEC for marine fish is a 28-d NOEC of of 25 µg Se/L for red sea bream (Pagrus major) obtained from a test in salt water with Na2SeO3.

All reliable chronic NOEC values are used for the derivation of a PNECwater based on the statistical extrapolation approach.

Key value for chemical safety assessment

Fresh water fish

Fresh water fish
Effect concentration:
10 µg/L

Marine water fish

Marine water fish
Effect concentration:
25 µg/L

Additional information

Reliable data for chronic toxicity to fish, are available for SeO2, H2SeO3, Na2SeO3, seleno-L-methionine and seleno-DL-methionine and for studies using combinations of these test substances (including Na2SeO4). These data cover 7 freshwater fish species (Pimephales promelas, Pogonichthys macrolepidotus and Brachydanio rerio (Cyprinidae), Lepomis macrochirus (Centrarchidae), Oncorhynchus mykiss and Oncorhynchus tshawytscha (Salmonidae), and Acipenser transmontanus (Acipenseridae)) and one marine species (Pargus major (Sparidae)). Results are available from studies in which fish were exposed to waterborne Se only, dietary Se only, or a combination of waterborne and dietary Se. The available effect concentrations include NOEC values expressed as waterborne Se, dietary Se and/or internal Se.

Only results based on dissolved Se concentration in the exposure media and obtained from studies in which Se was added to the test water only, are taken into account for the derivation of a PNECwater for direct effects. Reliable NOEC values based on waterborne Se are available for 4 freshwater fish species (B. rerio, P. promelas, L. macrochirus and O. mykiss) and one marine fish species (Pargus major) and range from 10 to 1000 µg Se/L. The lowest NOEC for freshwater fish was obtained in a study in which adult bluegills (Lepomis macrochirus) of 3 to 4 years old were exposed to a series of waterborne Se concentrations (added as Na2SeO3) in outdoor experimental streams in which fish were allowed to feed on naturally present food (Hermanutz et al., 1992). The adult fish were exposed for 258 days (pre-spawning period) + 98 days post-spawning. The NOEC of 10 µg Se/L represents a 258-d NOEC for pre-spawning mortality. The highest chronic NOEC for freshwater fish originates from a study in which fertilized eggs were exposed to a series of waterborne Se concentrations (added as SeO2) and larval mortality was observed until 10 days post-hatch (Niimi and LaHam, 1975). The NOEC of 25 µg Se/L for marine fish was obtained from a 28-day study on growth (daily length gain) of red sea bream (Pagrus major) exposed to seawater spiked with Na2SeO3 (Kim and Kang, 2014). A signifcant effect of approximately 20% was observed at the lowest dose tested (50 µg Se/L) and a NOEC was therefore determined as the lowest dose divided by 2.

All results are based on added dissolved Se concentrations. The data for Se-(D)L-methionine are not taken into account for the assessment of direct effects of inorganic selenium compounds to aquatic organisms because there is some concern on different biochemical behaviour of this selenium containing amino acid compared to inorganic Se compounds. Because no data are available for selenate, no comparison can be made between the long-term toxicity of selenite and selenate compounds to fish.

Results for dietary toxicity of Se to fish can be used for the secondary poisoning assessment of Se in the aquatic food chain. Reliable NOECoral values (expressed as mg Se/kg diet) were obtained from studies in which Se was added to the diet only. Results are available for 10 freshwater species and values range from 2.2 to 89.8 mg Se/kg diet (dw).

Although not used in the standard risk assessment, the available effects concentrations based on internal Se concentrations are discussed below. Reliable NOEC values based on internal Se were obtained from a series of studies in which Se was added either to the water or the diet only or added to both water and diet. The NOEC values (not considering unbounded values) varied between 3 and 12.6 mg Se/kg dw (whole body). The NOEC of 3 mg Se/kg dw results from a study in which juvenile bluegills (L. macrochirus) were exposed for 90 days to a series of dietary Se concentrations (added as seleno-L-methionine) (Cleveland et al., 1993). The NOEC was obtained for the endpoint survival. The NOEC of 12.6 mg Se/kg dw was reported by Hamilton et al. (1990) and resulted from a study in which fall Chinook salmon fingerlings (Oncorhynchus tshawytscha) were exposed for 120 days to a series of dietary Se concentrations (added as seleno-DL-methionine). The NOEC was obtained for the endpoints length and weight.

Some of the studies also reported reliable NOEC values based on Se concentrations in eggs or ovaries. It is generally accepted that tissue-based effect concentrations are more predictive of Se toxicity than diet borne and waterborne effect concentrations. From the NOEC values identified as reliable it is clear that tissue-based NOEC values show less variation than diet borne NOEC values and diet borne NOEC values in their turn show less variation than waterborne NOEC values.