Submitted to: International Workshop on Brominated Flame Retardants
Publication Type: Abstract Only
Publication Acceptance Date: May 13, 2005
Publication Date: June 13, 2005
Citation: Goel, A., Mcconnell, L.L., Torrents, A., Scudlark, J. 2005. Polybrominated diphenyl ethers in the atmosphere of the central delmarva peninsula [abstract]. Invited presentation at the Seventh Annual Workshop on Brominated Flame Retardants (BFR) in the Environment, June 13-14, 2005, National Institute of Standards and Technology, Gaithersburg, MD. p. 75.
Polybrominated Diphenyl Ethers (PBDEs) are an emerging class of pollutants which have been detected in almost all environmental compartments, including human milk, but data on their atmospheric concentrations is lacking. Weekly air samples (n=240, 2001-2003) were collected at three locations on the mid-Delmarva Peninsula to monitor the aerial concentrations of penta-BDEs (the congeners BDE-47, -99, -100 and 154) over time in this predominantly rural region. Two of the sites are close to the Atlantic coast in Delaware (Dover and Lewes), while one site is located near the mouth of the Choptank River in Maryland (Horn Point, Cambridge). PBDEs were present in 45% of the gaseous air samples from Horn Point, in 68% from Dover and in 99% from Lewes. Of the individual BDE congeners, BDE-99 was the most frequently detected (in 67% samples, n=240) followed by BDE-47 (61%) and BDE-100 (33%), whereas BDE-154 was not detected in the gas phase. The average concentrations at Horn Point and Dover (BDE 47: 13-19 pg/m3; BDE-99: 5.4-6.6 pg/m3) are comparable to that observed in rural Canada (BDE-47: 4.6 pg/m3; BDE-99: 4.3 pg/m3), suggesting that these sites reflect background levels. Lewes had average concentrations that were up to 5-10 times higher than at the other two sites. Analysis of the gaseous phase concentration data from Lewes using the Clausius-Clapeyron equation shows that temperature and time contribute 50% of the variability for BDE-47 (32% for BDE-99). Back trajectory analysis for the three sites suggests that the concentrations increase as the air mass travels over the Peninsula. Spray irrigation of municipal wastewater, a common practice for the counties on the Delmarva Peninsula, is suspected to be the source of PBDEs in the air at Lewes. Municipal wastewater and sludges have been identified as a major source of PBDEs. The aerial concentrations at Lewes are also increasing at an exponential rate; the atmospheric doubling times for the different congeners range from 1.3-2.4 yrs.