190 likes | 295 Views
Quantities of As in Florida. Purpose. Determine the relative magnitude of arsenic from CCA-treated wood versus the amounts from other arsenic sources Evaluate arsenic inputs, outputs, and reservoirs. Inputs/Outputs/Reservoirs. CCA-treated Wood Non-CCA Pesticides Geologic Sources Fuels
E N D
Purpose • Determine the relative magnitude of arsenic from CCA-treated wood versus the amounts from other arsenic sources • Evaluate arsenic inputs, outputs, and reservoirs
Inputs/Outputs/Reservoirs • CCA-treated Wood • Non-CCA Pesticides • Geologic Sources • Fuels • Fertilizers • Food Sources • Wastes Disposed Within State • Hydrosphere
AWPA,AWPI,SFPA~0.38 pcf (US) Florida Questionairre~0.76 pcf Methods: CCA Input: 31.2 million ft3/yr Extrapolated from Industry Statistics Average retention of 0.45 pcf (22% arsenic) (million ft3/yr)(retention) = 1,400 metric tons As/yr
Methods: non-CCA Pesticides • Cattle Dipping Vats (Historical Use) • MSMA/DSMA/Cacodylic Acid (Current Use) • Agriculture • Golf Course Use
MSMA/DSMA in Agriculture From the Nat. Center for Food and Ag. Policy, 2002
MSMA Use in Golf Courses Input = (Surface Area of Golf Courses) (Fraction of Golf Courses that Use MSMA) (Application Rate) Surface Area = Total Area from Florida Golf Courses Fraction of Golf Courses that Use MSMA = 0.96 (Ma et al. 2000) Application Rate = 11.7 lbs/acre/yr (from Hawaiian Study) Input ~ 500 metric tons As/yr
MSMA Stored in Golf Courses • DERM 1999: 16.9 mg/kg (0 to 1 or 2 ft composites) • Ma et al. 2000: 69.2 mg/kg Mass = (Surface Area of Golf Courses) x (Concentration)
Outputs Input Flux ~ 2,500 metric tons As/yr Output Flux ~ 10% of Input
Summary/Conclusions • Approx. 2,500 metric tons As imported per yr • CCA-treated wood (60%) • Arsenical pesticides,MSMA (20%) • Geologic Sources (15%) • About 10% of the imported As is exported Majority accumulates over time
Recommendations • In order to limit As impacts • Reduce use of MSMA • Properly dispose CCA-treated wood • Minimize impacts of CCA-treated wood currently in service