Editing Polybrominated diphenyl ethers (section)

===Sediment contamination===
Increasing environmental concentrations and changing distributions of PBDEs in sediments of the [[River Clyde|Clyde]] River Estuary in Scotland, UK have been assessed.<ref name="VaneMa2009">{{cite journal|last1=Vane|first1=Christopher H.|last2=Ma|first2=Yun-Juan|last3=Chen|first3=She-Jun|last4=Mai|first4=Bi-Xian| title=Increasing polybrominated diphenyl ether (PBDE) contamination in sediment cores from the inner Clyde Estuary, UK | journal=Environmental Geochemistry and Health | volume=32|issue=1|year=2009|pages=13–21|issn=0269-4042|doi=10.1007/s10653-009-9261-6|pmid=19347590|s2cid=102768|url=http://nora.nerc.ac.uk/id/eprint/9129/1/Vane_etal_2010_EGH.pdf}}</ref> Analysis of six sediment cores each of 1 m depth from [[Glasgow]] city to Greenock revealed that total concentrations increased toward the river bed surface (0–10&nbsp;cm). Amounts of PBDE ranged from 1 to 2,645&nbsp;µg/kg (dry wt. sediment) with a mean of 287&nbsp;µg/kg (dry wt. sediment).<ref name="VaneMa2009"/> Down-core PBDE congener profiles showed that higher concentrations were due to elevated levels of BDE-209. The majority of the sediment records clearly showed a change from mainly lower molecular weight BDEs 47,99, 183, 153 at lower depths to BDE-209 near the surface, a change in congener and homologue group patterns that corresponds to the restrictions of penta- and octaBDE commercial mixtures under EU law in 2004–2006.

While biodegradation is not considered the main pathway for PBDEs, [[Photodissociation|photolysis]] and [[pyrolysis]] can be of interest in studies of transformation of PBDEs.<ref>{{cite journal |author=Hutzinger O |title=Polybrominated dibenzodioxins and dibenzofurans |journal=[[Chemosphere (journal)|Chemosphere]] |volume=16 |pages= 1877–1880 |year=1987 |doi=10.1016/0045-6535(87)90181-0 |last2=Thoma |first2=H. |issue=8–9 |display-authors=etal|bibcode=1987Chmsp..16.1877H }}</ref><ref>{{cite journal |author=Watanabe I |title=Polybrominated diphenyl ethers in marine fish, shellfish and river sediments in Japan |journal=[[Chemosphere (journal)|Chemosphere]] |volume=16 |pages= 2389–2396 |year=1987 |doi=10.1016/0045-6535(87)90297-9 |last2=Kashimoto |first2=Takashi |last3=Tatsukawa |first3=Ryo |issue=10–12 |display-authors=etal|bibcode=1987Chmsp..16.2389W }}</ref>