The transformation of hexabromocyclododecane in aerobic and anaerobic soils and aquatic sediments

Occurrence of brominated flame retardants (BFRs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) in agricultural soils in a BFR-manufacturing region of North China

“…It is unknown whether this was because of the difference in diastereoisomer-specific vapor pressures of HBCD, which to our knowledge have not been reported. Another explanation was a shift from γ-HBCD to α-HBCD induced by photolytic isomerization and/or preferential degradation of γ-HBCD, which was previously observed (Davis et al, 2005;Harrad et al, 2009). Other BFRs, including BTBPE, PBT, PBEB, HBBs, and PBBs, showed the lowest concentrations and low detection frequencies in the soil, indicating that these BFRs were not manufactured in this region.…”

Hexabromocyclododecane and Hexachlorocyclohexane: How Lessons Learnt Have Led to Improved Regulation

“…On the basis of empirical data primarily, the half-life of HBCD in soil is ≥182 days (Environment Canada, 2011). Half-life in air >2 days 3.7 to 6.33 (Chen et al, 1984) 0.4 to 5.2 (Marvin et al, 2011) Half-life in water >60 days 3 to 300 days (Mackay et al, 1997) 60 to 130 days (Marvin et al, 2011) Half-life in aquatic sediments >180 days 90 days (WWFC, 1999) 0.9 to 12.6 years (Helm et al, 2002) 125-191 days (EC, 2008) Half-life in soil >180 days <180-1146<180- (IPCS, 1991 6.9 to 63 days (Davis et al, 2005) ≥182 days (Environment Canada, 2011) Half-life in biota (days/years) none 7 to 10 years (humans) (Zou and Matsumura, 2003) 23 to 219 days (humans) (Schecter et al, 2012) 1 to 17 days (mice) (Schecter et al, 2012) 53 to 136 days (fish) When released to the environment, HBCD isomers will adsorb onto solid particles of sediments and soil . Though there is a predominance (>90%) of γ-HCBD in the environment compared to α-and β-HBCD, α-HBCD often has the highest prevalence in biota, followed by β-HBCD (Birnbaum and Staskal, 2004).…”

Reductive transformation of hexabromocyclododecane (HBCD) by FeS

“…Growing evidence indicates that TBBPA and HBCD can be biodegraded via reductive dehalogenation in anoxic sediments (Davis et al, 2005(Davis et al, , 2006Ronen and Abeliovich, 2000;Voordeckers et al, 2002). For examples, Voordeckers et al (2002) observed microbial dehalogenation of TBBPA to bisphenol A in anoxic sediments, and Davis et al (2006) reported sequential debromination of HBCD by microbes in anoxic sediments via a series of dihaloelimination steps.…”