1,2-dibromoethane

Bioaccumulation: aquatic / sediment

Administrative data

Endpoint:

bioaccumulation: aquatic / sediment

Type of information:

other: Expert opinion based upon regulatory records chemicals.

Adequacy of study:

key study

Study period:

not reported.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Bioaccumulation potential for substances is estimated based upon measured test data for similar substances. The literature paper is authored by the Japanese Ministy of International Trade and Industry (MITI) and is reported in a peer reviewed journal.

Data source

Reference

Reference Type:

publication

Title:

Experiences with the Test Scheme under the Chemical Control Law of Japan: An Approach to Structure-Activity Correlations

Author:

Kawasaki, M.

Year:

1980

Bibliographic source:

Ecotoxicology and Environmental Safety (1980) Vol. 4, pp. 444-454.

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

This study does not present a theoretical approach but experimental analysis of the correlation between chemical structure and biodegradability or bioconcentration factors of various chemical substances, based on the consistent test data by MITI’s methods.

GLP compliance:

not specified

Test material

Reference

Name:

Unnamed

Type:

Constituent

Sampling and analysis

Details on sampling:

not reported.

Test solutions

Vehicle:

not specified

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

not reported.

Test organisms

Test organisms (species):

other: not applicable

Details on test organisms:

not reported.

Test conditions

Hardness:

not reported.

Test temperature:

not reported.

pH:

not reported.

Dissolved oxygen:

not reported.

TOC:

not reported.

Salinity:

not reported.

Details on test conditions:

not reported.

Nominal and measured concentrations:

not reported.

Details on estimation of bioconcentration:

It was derived from existing MIT1 test results that aliphatic compounds were generally less accumulated in fish except ones substituted by chlorine (Fig. 1). Degradation-resistant alcohols were less accumulated in fish, also. Regarding aromatic compounds, it is clearly recognized that the substituents cause significant effects on their bioaccumulation potential. Aromatic compounds reduce their bioaccumulation potential because of hydrophilic atomic groups, such as hlydroxy, amino, carboxy. nitro, or sulfo. On the other hand, chlorine increases the bioaccumulation potential of the compounds at the exponential ratio of the substituted numbers of chlorine (Figs. 2 and 3).
Naplhthalenes, anthracenes, or polyphenyl compounds generally present relatively higher accumulation potentials than the aliphatic compounds with nearly the same numbers of carbons. However, the substituents’ effects are deemed quite similar to those of the aromatic compounds. Figure 4 shows the results of MITI’s fish tests.
Definite correlation between the structures of polyphenylamines or substituents and their accumulation potential was not recognized from the test results (Fig. 5).

Results and discussion

Bioaccumulation factor

Type:

BCF

Value:

1 - 10 other: no data

Basis:

not specified

Calculation basis:

other:

Remarks on result:

other: Based upon other similar substances. See Figure 1.

Details on kinetic parameters:

not reported.

Metabolites:

not reported.

Results with reference substance (positive control):

not reported.

Details on results:

This study does not present the theoretical approach but experimental analysis of the correlation between chemical structure and biodegradability or bioconcentration factors of various chemical substances, based on the consistent test data by MITI’s methods. This result suggests that it is still difficult to generalize theoretically structure-reactivity correlations of chemical substances and to find the sufficient physical-chemical parameters which can predict the biodegradability or bioaccumulation potential of chemicals.

It is already proposed that physicochemical parameters such as water solubility, partition coefficient between water and n-octanol, etc., could be used for the prediction of bioaccumulation potential of chemical substances. Through this analysis it is quite clear that the existence of hydrophilic substituents (-OH, -SO, H) generally reduce the bioconcentration factors of the aromatic compounds, and that substituents’ effects of aliphatic compounds are not defined because the bioconcentration factor of aliphatic compounds are generally lower than that of aromatic compounds.

Chlorine’s effects are remarkable both on biodegradation and on bioaccumulation of organic chemical substances. Bioconcentration factors of aromatic compounds increase at the exponential rate according to the substituted numbers (Cl = 1-6) of chlorines. Finally this study suggests that theoretical interpretation of structure-activity correlation might be understood in studying which parameter is of importance in affecting biodegradability or bioaccumulation of each categorized chemical substance.

Reported statistics:

not reported.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The results suggests that it is still difficult to generalize theoretically structure-reactivity correlations of chemical substances and to find sufficient physical-chemical parameters which can predict the biodegradability or bioaccumulation potential of chemicals.