Upload
frey
View
58
Download
0
Tags:
Embed Size (px)
DESCRIPTION
Meeting Credits. Linda Russio: Organizer Patricia Chambers: Pulse, photos Todd Featherston and Mike May: IT Mike Connor: AM Session Bruce Thompson: PM Chair Sheila Tucker: Press liaison Jennifer Hunt: Timekeeper Jon Leatherbarrow: Video Lawrence Hall of Science All our speakers. - PowerPoint PPT Presentation
Citation preview
Linda Russio: Organizer Patricia Chambers: Pulse, photos Todd Featherston and Mike May: IT Mike Connor: AM Session Bruce Thompson: PM Chair Sheila Tucker: Press liaison Jennifer Hunt: Timekeeper Jon Leatherbarrow: Video Lawrence Hall of Science All our speakers
Meeting Credits
Choosing a Future Bay: The Long Term Fate of PCBs
and Other OrganicsJay Davis
Ben Greenfield
Jon Leatherbarrow
Nicole David
San Francisco Estuary Institute
One Box Mass Budgets
OUTPUTSOutflowBurialVolatilizationDegradation
INPUTSDischargesRunoffAtmosphereHotspot erosion
PCBs Present concentrations about 10 times higher than
threshold for concern Slow decline in the Bay in last 20 years New sources minimal – restricted in 1979 Residual loading from watershed and atmosphere Degradation is negligible Associate with sediment particles Somewhat volatile One-box final report in press, multi-box draft by
January 2004
Year
0 10 20 30 40 50 60 70 80 90 1000
500
1000
1500
2000
2500
3000
50% of present
25% of present
10% of present
0 kg
Predicted Long Term Trends in PCB Mass (kg) with Varying Loads
Year
0 10 20 30 40 50 60 70 80 90 1000
500
1000
1500
2000
2500
3000
50% of present
25% of present
10% of present
20 kg
10 kg 0 kg
Predicted Long Term Trends in PCB Mass (kg) with Varying Loads
PAHs
Present concentrations at threshold for concern
No clear trend in the Bay in last 20 years Masses are large Degradation is significant Significant continuing inputs Associate with sediment particles Somewhat volatile One-box final report in prep
Year
0 10 20 30 400
20000
40000
60000
80000
100000
120000
140000
50% of present
0 kg
7500 kg
15000 kg
Predicted Long Term Trends in PAH Mass (BBF, kg) with Varying Loads
Organochlorine Pesticides
Present concentrations at threshold for concern Decline in the Bay in last 20 years New sources minimal – cancelled in 1972 Residual loading from watershed and
atmosphere Degradation is faster than PCBs Associate with sediment particles Somewhat volatile One-box draft report out soon
Year
0 10 20 30 400
100
200
300
400
500
50% of present
Predicted Long Term Trends in DDT Mass (kg) with Varying Loads
0 kg
20 kg
40 kg
PBDEs
Threshold for concern not well known Concentrations exponentially increasing Use is increasing Loading up the “blenders” in the Bay and
the watershed Degradation probably minimal Associate with sediment particles Less volatile than PCBs No full analysis yet
PBDEs have NOT been thoroughly reviewed yet
Model can be used to get a preliminary peek at the how the Bay would generally respond to this TYPE of scenario
Increasing Loading Scenario
Year
0 10 20 30 40 50 60 70 80 90 1000
500
1000
1500
2000
2500
3000Exponential Increase
EI for 10 yr, then 40 kg/yr
EI for 10 yr, then 0 kg/yr
PBDE-like Loading Scenarios
Year
0 10 20 30 40 50 60 70 80 90 1000
500
1000
1500
2000
2500
3000
EI for 10 yr, then 0 kg/yr
EI for 20 yr, then 0 kg/yr
PBDE-like Loading Scenarios
Next Steps for Modeling in the RMP
Contaminant Fate Workgroup meets tomorrow
Local scientists and invited members Joel Baker and Tom McKone
Multiple boxes
A Multi-box Model
Next Steps for Modeling in the RMP (cont)
Quantify uncertainty Extend food web model Better input data
– Sediment dynamics– Degradation rates– Outflow – Average concentrations– Historic long term trends
Closing Remarks