Trimethyl borate

Bioaccumulation: terrestrial

Administrative data

Endpoint:

bioaccumulation: terrestrial

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)

Data source

Reference

Reference Type:

publication

Title:

Effects of Boron and Selenium on Mallard Reproduction and Duckling Growth and Survival

Author:

Stanley , TR, GJ Smith, DJ Hoffman, GH Heinz and R Rosscoe.

Year:

1996

Bibliographic source:

Environmental Toxicology and Chemistry, Vol. 15, No 7. pp. 1124-1132, 1996

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

One hundred and twenty-six pairs of breeding mallards were fed diets supplemented with boron at 0, 450, or 900 ppm in combination with Se at 0, 3.5, or 7 ppm, in a replicated factorial experiment. Ducklings produced received the same treatment combination as their parents.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Boric acid

EC Number:

233-139-2

EC Name:

Boric acid

Cas Number:

10043-35-3

IUPAC Name:

10043-35-3

Constituent 2

Reference substance name:

boric acid

IUPAC Name:

boric acid

Details on test material:

- Name of test material (as cited in study report): boric acid
- Analytical purity: 99.9% pure ; Fisher Scientific, Fair Lawn, NJ, USA

Radiolabelling:

no

Sampling and analysis

Details on sampling:

- Sampling intervals/frequency for test organisms: the eighth egg was removed from each nest and 14d after hatching the ducklings and their parents were euthanized. Samples of liver, kidney, and spleen from 10 randomly selected hens, drakes, and ducklings were saved in 10% buffered formalin.
- Sample storage conditions before analysis: content of eggs were frozen, ducklings and parents were weighted and the liver removed, weighted and frozen for analysis
- Details on sampling and analysis of test organisms and test media samples (e.g. sample preparation, analytical methods):

Test substrate

Vehicle:

no

Test organisms

Test organisms (species):

other: Anas platyrhynchos

Details on test organisms:

TEST ORGANISM
- Common name: mallards
- Source: Outdoorsman Hunting Club, Webb, IA, USA
- Age at test initiation (mean and range, SD): 1-year-old
- Weight at test initiation (mean and range, SD):


ACCLIMATION
- Acclimation period: 17 days
- Feeding : untreated diet of commercially available developer mash
- Females were kept under controlled lighting (8h/d) to delay the onset of egg laying and to synchronize their cycles

Study design

Total exposure / uptake duration:

ca. 120 d

Test conditions

Details on test conditions:

TEST SYSTEM
- Test container (material, size): 1m² outdoor pens
- No. of organisms per container (treatment): 1
- No. of replicates per treatment group: 14
- No. of replicates percontrol / vehicle control: 14

Nominal and measured concentrations:

Added concentrations in diet are 450 and 900 ppm boron

Results and discussion

Bioconcentration factor

Bioconcentration factor 1

Type:

BCF

Value:

0.03 dimensionless

Basis:

organ d.w.

Remarks on result:

other: adult liver

Bioconcentration factor 2

Type:

BCF

Value:

0.05 dimensionless

Basis:

organ d.w.

Remarks on result:

other: whole eggs

Details on results:

- Observations on body length and weight: weight loss in females between treatment onset and pairing (3 weeks) in the 900-ppm treatment group
- Other biological observations: egg weight and egg fertility were lower in the 900-ppm treatment group

Reported statistics:

Data were analyzed by logistic regression under a mixed effects model with parameters for main and interactive effects between Band Se, and a pen effect. Parameters were tested for significance with F tests; multiple comparisons were made using contrasts. All remaining response wariables were analyzed by analysis of variance under a model appropriate for the main effects and interactions being tested and an error term suitable for unbalanced data. Tests of hypotheses that included more than one bird per pen were made with F tests under a mixed effects model using an appropriate error term. All other F tests assumed a fixed effects model and used the residual mean square as the error term. Normality of residuals was evaluated using the Shapiro-Wilk statistic and normal probability plots. Studentized residuals were plotted to assess homoscedasticity. Data that did not meet normality or homosccedasticity assumptions necessary for ANOVA were transformed so as to meet the assumptions. Consequently, all percentage data were arcsine transformed and all residue data were log. transformed before analysis. Multiple comparisons were made using Tukey's multiple comparison procedure (MCP) at alpha = 0.05.

Any other information on results incl. tables

Boron accumulates rapidly in adult mallard liver and is estimated to take 2.8d to reach 95% of its asymptotic level. On a dry-weight basis, B in adult liver in the control, 450 -, and 900 -ppm B treatments groups was 2, 15, and 27 ppm, respectively.

Dry-weight concentrations of B in eggs were 0.6, 22, and 38 ppm in the B control, and 450- and 900 -ppm treatment groups, respectively.