Registration Dossier

Administrative data

Endpoint:
phototransformation in soil
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2000
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Published in the literature. Authors have published several papers on photodegradation of DecaBDE. This paper's conclusions regarding a field study do not support the conclusions reached in their laboratory work.

Data source

Referenceopen allclose all

Reference Type:
publication
Title:
Effect of sewage-sludge application on concentrations of higher-brominated diphenyl ethers in soils and earthworms.
Author:
Sellstrom et al.
Year:
2005
Bibliographic source:
Environ. Sci. Tehcnol 39:9064-9070
Reference Type:
publication
Title:
Photolytic debromination of decabromodiphenyl ether (BDE 209).
Author:
Soderstrom et al.
Year:
2004
Bibliographic source:
Environ Sci Technol 38(127-132)

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Soil and earthworms collected from 3 research stations and 2 farms in Sweden. Soils amended with sewage sludge containing DecaBDE or periodically flooded with river sediment containing DecaBDE. Soil and earthworms analyzed for PBDE content. At least one analysis performed 20+ years after last application of sewage sludge containing DecaBDE.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Radiolabelling:
no

Study design

Analytical monitoring:
yes
Analytical method:
other: GC-MS, m/z:-79,-81, -487, -489
Light source:
sunlight
Duration of test at given test condition
Duration:
20 yr
Reference substance:
no
Dark controls:
no

Results and discussion

% Degradation
% Degr.:
0
Sampling time:
20 yr
Transformation products:
no
Details on results:
Soil was collected from 3 research stations (reference plots and sewage-sludge-amended plots) and 2 farms (reference and amended/flooded soils) in Sweden. [BDE209] in background (reference) soils ranged from 0.015 -0.75 ng/g dw, except for 1 farm which was impacted by river sediment flooding was 1.9 ng/g dw. At the 3 research stations which had been amended with sewage sludge, the concentrations ranged from 0.028 -1.0 ng/g dw. One farm where sewage-sludge had been applied had [BDDE209] of 2200 ng/g dw. The other farm which was periodically flooded by the River Visken, which received effluents from textile industries, had [BDE209] of 350 ng/g dw. The farm with the highest [BDE209] had last recieved sludge application 20 yr prior to sampling. The authors concluded no evidence of photolytic breakdown of BDE209 was seen based on the chromatograms of the soils, in contrast to their previous work indicating photolytic debromination of BDE209 applied to "artificially to soil with solvent in laboratory and field experiments (Soderstrom et al. 2004). Further, laboratory experiments with the high-BDE209 -soil showed no change in peak patterns with the lenght of UV exposure. The authors indicated soil ageing ahs been shown to encapsulate and shield contminants so they are less accessible to microbial breakdown, and also probably sunlight. The fact that the soils were plowed under was also thought to impact sunlight exposure. The authors concluded "The results with soils collected in the field show the importance of following up laboratory studies with field studies."

Any other information on results incl. tables

Soil was collected from 3 research stations (reference plots and sewage-sludge-amended plots) and 2 farms (reference and amended/flooded soils) in Sweden. [BDE209] in background (reference) soils ranged from 0.015 -0.75 ng/g dw, except for 1 farm which was impacted by river sediment flooding was 1.9 ng/g dw. At the 3 research stations which had been amended with sewage sludge, the concentrations ranged from 0.028 -1.0 ng/g dw. One farm where sewage-sludge had been applied had [BDDE209] of 2200 ng/g dw. The other farm which was periodically flooded by the River Visken, which received effluents from textile industries, had [BDE209] of 350 ng/g dw. The farm with the highest [BDE209] had last recieved sludge application 20 yr prior to sampling. The authors concluded no evidence of photolytic breakdown of BDE209 was seen based on the chromatograms of the soils, in contrast to their previous work indicating photolytic debromination of BDE209 applied to "artificially to soil with solvent in laboratory and field experiments (Soderstrom et al. 2004). Further, laboratory experiments with the high-BDE209 -soil showed no change in peak patterns with the lenght of UV exposure. The authors indicated soil ageing ahs been shown to encapsulate and shield contminants so they are less accessible to microbial breakdown, and also probably sunlight. The fact that the soils were plowed under was also thought to impact sunlight exposure. The authors concluded "The results with soils collected in the field show the importance of following up laboratory studies with field studies."

Applicant's summary and conclusion

Validity criteria fulfilled:
not specified
Conclusions:
Photolytic degradation of BDE209 was not observed in farm soils exposed to BDE209 by atmospheric depostion, sewage-sludge-amendment, and/or river flooding. Some of the farm soils last recieved sludge-amendment more than 20 yrs prior to measurement. No evidence of microbial degradation was observed.
Executive summary:

Soil was collected from 3 research stations (reference plots and sewage-sludge-amended plots) and 2 farms (reference and amended/flooded soils) in Sweden. [BDE209] in background (reference) soils ranged from 0.015 -0.75 ng/g dw, except for 1 farm which was impacted by river sediment flooding was 1.9 ng/g dw. At the 3 research stations which had been amended with sewage sludge, the concentrations ranged from 0.028 -1.0 ng/g dw. One farm where sewage-sludge had been applied had [BDDE209] of 2200 ng/g dw. The other farm which was periodically flooded by the River Visken, which received effluents from textile industries, had [BDE209] of 350 ng/g dw. The farm with the highest [BDE209] had last recieved sludge application 20 yr prior to sampling. The authors concluded no evidence of photolytic breakdown of BDE209 was seen based on the chromatograms of the soils, in contrast to their previous work indicating photolytic debromination of BDE209 applied to "artificially to soil with solvent in laboratory and field experiments (Soderstrom et al. 2004). Further, laboratory experiments with the high-BDE209 -soil showed no change in peak patterns with the lenght of UV exposure. The authors indicated soil ageing ahs been shown to encapsulate and shield contminants so they are less accessible to microbial breakdown, and also probably sunlight. The fact that the soils were plowed under was also thought to impact sunlight exposure. The authors concluded "The results with soils collected in the field show the importance of following up laboratory studies with field studies."