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Prepared by: Gary Jacobi. Extent of CCA Treated Wood in Consumer Mulches and Methods of Detection. Mulch made from C&D Wood. Objectives. Determine the extent to which CCA-treated wood has contaminated consumer mulches Determine if visual methods can be used to identify suspect mulch
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Prepared by: Gary Jacobi Extent of CCA Treated Wood in Consumer Mulches and Methods of Detection
Objectives • Determine the extent to which CCA-treated wood has contaminated consumer mulches • Determine if visual methods can be used to identify suspect mulch • Determine if X-ray fluorescence (XRF) technology can be used to identify suspect mulch
Mulch Analysis Methods Visual Inspection Physical Analysis Size Distribution Sample Ash for Total Metals Chemical Analysis SPLP Analysis XRF Analysis
Visual Inspection Plywood and Foreign Objects (Nails, Plastic, Rubber, Glass, String, Rocks, Etc.)
Size Distribution • Uniformity Coefficient (UC): • The UC will approach 1 if the pieces of sample are the same size • d50: The size in inches that 50% of the sample is finer than
Visual Analysis * 73% mulches with plywood are colored
Results: Size Distribution • Average d50 of samples was 0.29 in. • Average Uniformity Coefficient was 5.0
Chemical Analysis Visual Inspection Physical Analysis Size Distribution Sample Ash for Total Metals Chemical Analysis SPLP Analysis XRF Analysis
Total Metals Results Analysis Procedure XRF Leachable Results
Results: Ash for Total Metals Ashed Samples: 84 Colored Not Colored 44 40 As > 2.1 mg/kg As < 2.1 mg/kg As > 2.1 mg/kg As < 2.1 mg/kg 13 31 4 36
Results: Ash for Total Metals Fraction of Samples in Category with Values Greater Than Indicated Category X X X X
Pensacola Jacksonville Tallahassee Gainesville Sebastian Orlando Tampa Legend Lake Worth St. Pete Brandon Arsenic <0.07 – 2.1 mg/kg Arsenic 3.7 – 50 mg/kg Fort Myers South Florida Arsenic 50 – 100 mg/kg Arsenic greater than 100 mg/kg City Location Key Largo Colored Marathon Non-Colored
Mulch SPLP Results SPLP Samples: 84 Colored Not Colored 44 40 Positive for As Not Positive for As Positive for As Not Positive for As 13 31 2 38
SPLP Table X X X X
Tallahassee Pensacola Jacksonville Gainesville Sebastian Orlando Tampa Legend Lake Worth St. Pete Arsenic below detection limit Brandon Arsenic 12–20 ug/L Fort Myers Arsenic 21-50 ug/L South Florida Arsenic greater than 51 ug/L City Location Key Largo Colored Marathon Not Colored
Conclusion • 52% are colored mulches • 12% colored mulches positive for arsenic • 17% mulches contained plywood • 67% mulches with plywood positive for arsenic • 87% mulches with plywood were colored • 73 % of colored mulches with plywood contained arsenic • 44 % of South Florida samples detected positive for arsenic in SPLP analysis • 75 % of open bin mulches contained high concentrations of arsenic
Conclusion • Engineered wood was found in 21% of consumer mulches • Arsenic was found in 28% consumer mulches • SPLP tested showed that arsenic leached from 27 % of consumer mulches • 48% of these samples leached over 50 μg/L • XRF is capable of spotting arsenic in mulch, especially mulch with higher concentrations
Questions • Draft Report on-line at www.ccaresearch.org under the “publications” link • Comments accepted on report until August 30th