1. SETAC North America 28th Annual Meeting
A Mass Budget of Polybrominated Diphenyl Ethers in San Francisco Bay, CA
John J. Oram, Lester J. McKee, Christine E. Werme, Mike S. Connor, and Daniel R. Oros
SETAC North America 28th Annual Meeting
November 2007

2. Conceptual Model
Total Export
Total Load
Inventory
Depth
PBDEs ?

3. Pieces of the Mass Budget
Inventory
Water and sediment monitoring
External Loads
Local Watersheds
The Delta
Wastewater
Atmospheric Deposition
Losses
Golden Gate Outflow
Degradation
Volatilization

4. Bay Inventory Inventory* 33.5 ± 2.6 kg BDE 47 151.6 ± 45.4 kg BDE 209
* Spatially unbiased GRTS value

5. Guadalupe River WY 2005 Lower (Urban) Upper (Rural) WY05 WY06
SSC (mg/L)
WY05
WY06
WY 2005
Lower (Urban)
Upper (Rural)

6. Mallard Island (the Delta)
BDE-47 (ng/L)
SSC (mg/L)
Use Flow-Weighted Mean Concentration

7. Spatial Congener Patterns BDE 47 : BDE 209 (concentration basis)
Why less BDE 209 at Delta?
Atmospheric deposition
47 more volatile than 209
Dissolved loads
47 more soluble than 209
Long residence time of Delta
1.2
0.2

8. Summary of Loads (kg)

9. Hindcast – Estimation/Verification of Loads
BDE 47
From Field Studies:
BDE 47 ~11-28 kg/yr
BDE 209 ~22-24 kg/yr
Missing Something…
Missing source?
Study years differ
209 QA/QC
Model parameters incorrect?
BDE 209
Time (years)

10. Emerging Conceptual Model
Total Export
Outflow >>
Degradation >>
Volatilization
Total Load
11-28 (25) kg/yr BDE 47
22-24 (100) kg/yr BDE 209
~34 kg BDE 47
~152 kg BDE 209
Depth
PBDEs ?
Erosion / Deposition
Poorly Known