Several newly published studies on brominated flame retardants. BDE-209 is deca-brominated diphenyl ether, still being produced and used in large quantities in consumer products and a significant environmental contaminant in the GL region. Evidence of debromination of deca and transformation into toxic byproducts also demonstrated.
Venier, M., Hites, R., 2008. Flame Retardants in the Atmosphere near the Great Lakes. Environmental Science & Technology. Article in Press. 10.1021/es800313z
As part of the Integrated Atmospheric Deposition Network (IADN), air samples were collected at five sites around the Great Lakes (two urban, two rural, and one remote) every 12 days during 2005-2006, and the concentrations of polybrominated diphenylethers (PBDEs), 1,2-bis(2,4,6-tribromophenoxy)-ethane (TBE), Dechlorane Plus (DP), and decabromodiphenyl ethane (DBDPE) were measured.The highest mean concentrations of total PBDEs were found at the urban sites in Chicago and Cleveland (65 ± 4 and 87 ± 8 pg/m3, respectively), and the lowest at the remote site in Eagle Harbor (5.8 ± 0.4 pg/m3). With the exception of Chicago, the atmospheric concentrations of BDE-47 and 99 (summed over the gas and particle phases) are decreasing rapidly with half-lives of ∼ 2 years, but the concentrations of BDE-209 are not decreasing at any of the five sites. The atmospheric partial pressures of BDE-47 and 99 showed a strong Clausius-Clapeyron relationship with reciprocal atmospheric temperature. TBE, DBDPE and DP were detected at all sites, but with the exception of Chicago, there were insufficient data to determine temporal trends for these compounds. The influence of human population density and synoptic atmospheric transport patterns was explored to explain the relatively high concentrations of BDE-209 in Cleveland.
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? backward air trajectories were overlaid on a map of BDE-209 sources obtained from the EPA?s Toxic Release Inventory (TRI). The air masses corresponding to low BDE-209 concentrations were mainly coming from Lake Erie, whereas those corresponding to high BDE-209 concentrations were mainly coming from directions with facilities emitting BDE-209 into the atmosphere. Even without considering distant sources, the area surrounding Cleveland seems to have a high density of facilities emitting BDE-209, as opposed to Chicago, where the TRI indicated that there were none.
Allen et al., 2008. Critical factors in assessing exposure to PBDEs via house dust. Environment International. Article in Press. doi: 10.1016/j.envint.2008.03.006
Assessment of indoor exposure to polybrominated diphenyl ethers (PBDEs) requires a critical examination of methods that may influence exposure estimates and comparisons between studies. We measured PBDEs in residential dust collected from 20 homes in Boston, MA, to examine 5 key questions: 1) Does the choice of dust exposure metric?e.g., concentration (ng/g) or dust loading (ng/m2)?affect analysis and results? 2) To what degree do dust concentrations change over time? 3) Do dust concentrations vary between rooms? 4) Is
the home vacuum bag an acceptable surrogate for researcher-collected dust? 5) Are air and dust concentrations correlated for the same room? We used linear mixed-effects models to analyze the data while accounting for within-home and within-room correlations. We found that PBDE dust concentration and surface loading were highly correlated (r=0.86?0.95, p<0.001). Average dust concentrations did not significantly differ over an 8-month period, possibly because home furnishings changed little over this time. We observed significant differences between rooms in the same home: PBDE concentrations in the main living area were 97% higher than the bedroom for decaBDE (p=0.02) and 72% higher for pentaBDE (p=0.05). Home vacuum bag dust concentrations were significantly lower than researcher-collected dust and not strongly correlated. Air (vapor and particulate phase) and dust concentrations were correlated for pentaBDE (p=0.62, pb0.01), but not for decaBDE (p=0.25). In addition, potential markers of BDE 209 debromination (BDE 202 and the BDE197:BDE201 ratio) were also observed in household dust samples. One vacuum bag sample contained the highest concentrations of BDE 209 (527,000 ng/g) and total PBDEs (544,000 ng/g) that
have been reported in house dust.
Photolysis Studies of Technical Decabromodiphenyl Ether (DecaBDE) and Ethane (DeBDethane) in Plastics under Natural Sunlight
Natsuko Kajiwara,* Yukio Noma, and Hidetaka Takigami
ASAP Environ. Sci. Technol.,
ASAP Article, 10.1021/es800060j
Photodebromination of technical decabromodiphenyl ether (DecaBDE) incorporated into high-impact polystyrene (HIPS) and TV casings was compared under natural sunlight conditions with that of technical decabromodiphenyl ethane (DeBDethane). BDE 209 in pulverized HIPS+DecaBDE samples degraded with a half-life of 51 days. In contrast, no marked loss of DeBDethane occurred throughout the experimental period of 224 days. During BDE 209 photolysis in HIPS+DecaBDE samples, partly debromination to nona- and octa-BDE was observed, however, environmentally relevant polybrominated diphenyl ether (PBDE) congeners such as BDE 47, 99, and 100 were not formed. Formation of polybrominated dibenzofurans (PBDFs) was clearly apparent in the flame-retarded plastics that we investigated. In the HIPS+DecaBDE samples, the PBDF concentration increased by about 40 times after 1 week of exposure, with a concomitant decrease in BDE 209. In the TV casing, tetra- to octa-BDF congener concentrations increased continuously during the experiment. Although the concentrations of PBDFs found in the plastic matrices tested were 1 to 4 orders of magnitude lower than those of PBDEs, more attention should be paid to the fact that PBDFs are formed by sunlight exposure during normal use as well as disposal/recycling processes of flame-retarded consumer products.