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Ecotoxicological information

Toxicity to aquatic plants other than algae

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Administrative data

Endpoint:
toxicity to aquatic plants other than algae
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Peer-reviewed technical publication that meets basic scientific principles.

Data source

Reference
Reference Type:
publication
Title:
Toxicity of boron to the duckweed, Spirodella polyrrhiza
Author:
Davis, SM, KD Drake and KJ Maier
Year:
2002
Bibliographic source:
Chemosphere 48, 615-620

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EPA OPPTS 850.4400 (Aquatic Plant Toxicity Test using Lemna spp. Tiers I & II))
Deviations:
yes
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent

Sampling and analysis

Analytical monitoring:
yes
Details on sampling:
On day 1, 4, 7 and 10, three 24h samples for each concentration were collected.
All samples were stored at 4°C until analysis.

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
other: Spirodella polyrrhiza
Details on test organisms:
TEST ORGANISM
- Common name: Duckweed
- Source : existing laboratory culture

Study design

Test type:
semi-static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
10 d

Test conditions

Test temperature:
25 +- 1 °C
Nominal and measured concentrations:
Nominal concentrations : 0.5, 3, 6, 17, 25 and 37 mg B/L
To verify B exposure, water samples were analyzed using the colorimetric curcumin method as described by Allen (1974). Mean concentrations of time 0 and 24 hr samples were: 0.9 (control), 3.6, 6.5, 19.2, 24.0, and 40.0 mg B/L. B concentrations for days 4, 6 and 10 were not reported. Authors expressed endpoints based on time 0 concentrations, but mean values are used below.
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 50 ml plastic cups filled with 45 ml of boron-containing nutrient media
- Renewal rate of test solution (frequency/flow rate): daily
- No. of fronds per colony: 14-16
- No. of vessels per concentration (replicates): 6


TEST MEDIUM / WATER PARAMETERS
- Source/preparation of dilution water: pH stabilized nutrient media (Clatworthy and Harper, 1962)


OTHER TEST CONDITIONS
- Photoperiod, light intensity and quality: 24h light from normal chamber illumination + two 24-in. Lampi Flora Plant lights each fitted with 20 W wide-spectrum fluorescent lights were placed +- 12 in. above the test chambers.


EFFECT PARAMETERS MEASURED :
- Determination of frond number: On day 0 and 10,frond number was determined, and observations of fronds were made. Chlorosis, necrosis and death were observed and classified as abnormal fronds.

Results and discussion

Effect concentrationsopen allclose all
Duration:
10 d
Dose descriptor:
LOEC
Effect conc.:
3.6 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Basis for effect:
frond number
Duration:
10 d
Dose descriptor:
NOEC
Effect conc.:
6.5 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Basis for effect:
growth rate
Duration:
10 d
Dose descriptor:
LOEC
Effect conc.:
19.5 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Basis for effect:
growth rate
Details on results:
Total frond production reduced at next higher exposure (3.6 mg B/L) so no NOEC for total frond number can be derived
Reported statistics and error estimates:
Statistical analysis was performed using TOXSTAT 3.5 and ANOVA. The ANOVA and Tukey's HSD were performed to measure statistical differences between boron concentrations on days 0 and 10. These statistical tests were also used to analyze differences in initial concentrations and 24-h sample boron concentrations. Significance was determined using p =< 0.05 for all statistical tests.

Any other information on results incl. tables

Duration Endpoint Effect conc. Nominal/Measured Conc. based on Basis for effect Remarks (e.g. 95% CL)
10 d LOEC 3.6 mg/L meas. (not specified) element frond number unbounded LOEC
10 d EC50 14.3 mg/L meas. (not specified) element frond number
10 d NOEC 6.5 mg/L meas. (not specified) element growth rate
10 d LOEC 19.2 mg/L meas. (not specified) element growth rate
10 d EC50 11.7 mg/L meas. (not specified) element growth rate

Applicant's summary and conclusion