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Ecotoxicological information

Toxicity to other aquatic organisms

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Administrative data

Endpoint:
toxicity to other aquatic vertebrates
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Peer-reviewed technical publication that meets basic scientific principles. Non-standard design - only two exposures tested

Data source

Reference
Reference Type:
publication
Title:
Effects of Boron and Nitrate on Hatching Success of Amphibian Eggs
Author:
Laposata, MM and WA Dunson
Year:
1998
Bibliographic source:
Arch. Environ. Contam. Toxicol. 35, 615-619

Materials and methods

Principles of method if other than guideline:
Eggs of amphibians were exposed to boron concentrations (0, 50, 100 mg B/L) under laboratory conditions.
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): sodium tetraborate
- Molecular formula (if other than submission substance): Na2B4O7.10H2O

Sampling and analysis

Analytical monitoring:
yes

Test solutions

Vehicle:
no

Test organisms

Test organisms (species):
Ambystoma jeffersonianum
Details on test organisms:
TEST ORGANISM
- Common name: Jefferson salamander
- Source: Egg masses were collected on April 2-3, 1997, from unirrigated ponds in the western portion of SGL 176 in Centre County, Pennsylvania. The masses were returned to the lab on ice and stored in pond water from their collection site. All eggs were in the blastula stage.

Study design

Test type:
static
Water media type:
freshwater
Limit test:
no
Total exposure duration:
25 d

Test conditions

Hardness:
186.5 mg/L
Test temperature:
10 °C
pH:
6.5
Nominal and measured concentrations:
Nominal concentrations : 0, 50 and 100 mg B/L
Measured concentrations : 0, 49.50 and 100.24 mg B/L
The B concentrations changed little over the course of the experiments (<5%)
Details on test conditions:
TEST SYSTEM
- Test vessel:
- Material, size, headspace, fill volume: 2.4 L polyethylene containers
- No. of organisms per vessel: 15
- No. of vessels per concentration (replicates): 5


OTHER TEST CONDITIONS
- Adjustment of pH: All solutions were adjusted to pH 6.5 with dilute H2SO4 or KOH to simulate the pH of irrigated ponds.
- Photoperiod: 12 h light : 12 h dark
- Light intensity: 40 W fluorescent overhead lights


EFFECT PARAMETERS MEASURED (with observation intervals if applicable) : The number of dead, deformed, and hatched eggs was recorded weekly until the first evidence of hatching at witch point the containers were monitored every other day. The number of successfully hatchting larvae and the number of hatchlings with deformities were scored after hatching.

Results and discussion

Effect concentrations
Duration:
25 d
Dose descriptor:
LOEC
Effect conc.:
<= 49.5 mg/L
Nominal / measured:
meas. (not specified)
Conc. based on:
element
Basis for effect:
morphology
Remarks:
larval deformation
Remarks on result:
other: unbounded LOEC
Reported statistics and error estimates:
The proportion of eggs that successfully hatched and/or the proportion of deformed larvae were compared across levels in each experiment with one-way ANOVAs for each species, followed by Tukey multiple comparison tests if a significant effect was found. All proportional data were arcsine-transformed prior to analysis. Multiple comparisons were corrected with the sequential Bonferroni Type I error rate adjustment (Rice 1989). In this method, the p values from each of K comparisons are ranked in increasing order and compared to critical p values of 0.05/K, 0.05/K-1, 0.0K-2, and so on. If the lowest p value is lower than 0.05/K it is considered significant, and the next lowest p value is compared to 0.05/K-1. This continues until Pi >= 0.05/K-i when that and all subsequent p values are considered nonsignificant. All statistical tests utilized Minitab V.10 statistical software (Minitab 1994).

Any other information on results incl. tables

25d NOEC hatching succes >= 100 mg/L

Applicant's summary and conclusion