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1K - Tropospheric Fate (MO13/2) Concentrations of PBDEs in ambient air from southern Ontario: Evidence of a "spring pulse" effect. Gouin, Todd1, Harner, Tom2, Jones, Kevin3, Mackay, Don1, 1 Trent University, Peterborough, Ontario, Canada2 Environment Canada, Toronto, Ontario, Canada3 Lancaster University, Lancaster, England, United Kingdom ABSTRACT- Recent studies have suggested that organic compounds with high octanol-air partition coefficients, such as polybrominated diphenyl ethers, are subject to an atmospheric "spring pulse". This is a period of high concentrations in the air during the early spring, shortly after snow melt and before bud-burst. To study this phenomenon hi-volume air samples were collected from January to June, 2002 at a rural location in southern Ontario. Air concentrations for BDE-47, the dominant congener in the samples, ranged from below detection during the winter to a maximum of 10 pg m-3 in the early spring. Other prominent congeners were 99, 17 and 28 and Key words: PBDEs, Passive air samplers, air concentrations, spring pulse |
BDE peaked at 20 pg m-3 in the spring. Levels in air then decreased to below the detection limit shortly following bud-burst suggesting that the emergence of foliage in the early spring strongly influences the atmospheric concentrations of compounds with high octanol-air partition coefficients, such as the PBDEs, and that this may be an important process that inhibits their long-range transport. In addition to the hi-volume air samples, passive air samplers were deployed along an urban-rural transect for a one month period prior to bud-burst. These samplers were then replaced with a second set of passive samplers for a one-month period following bud-burst. The data from both the active and passive samples were in good agreement. Higher air concentrations were also observed in the passive samples prior to the emergence of foliage. The passive sampling campaign was also used to investigate differences in atmospheric concentrations of these compounds in urban, rural and forested locations, and to to identify the source signatures of the PBDEs.