Kate McIntosh Wadsworth Center, NYSDOH LCC Workshop June 8, 2012

1. Performance of current XRF instrumentation for measuring the lead content of environmental samples Kate McIntosh Wadsworth Center, NYSDOH LCC Workshop June 8, 2012

2. Outline • Background • X-Ray Optical Systems and Monochromatic XRF (M-XRF) • Lead in painted toys and consumer products • Instrumentation • XOS HD-Prime • Thermo Scientific Niton XL3t • Inter-laboratory study and reference materials • Lead in household paint • Screening with the XL3t • Conclusions and summary recommendations • Future work • XOS Personal Environmental Analyzer (PEA)

3. X-Ray Optical Systems • Industry collaborator • Leader in development and manufacture of x-ray optics • Interest in developing new technologies for environmental applications • Prototype instruments based on monochromatic XRF (M-XRF) for specific public health problems • Advantages: • Reduced background provides improved P/B and greater sensitivity • No loss in intensity due to scatter in filter, so low power sources can be used East Greenbush, NY X-Beam® Doubly Curved Crystal (DCC) optic

4. Lead in painted toys and consumer products

5. XOS HD-Prime For painted products: Measure painted region Measure substrate cameras 1 mm spot size ≤7 minutes sample chamber Calibration modes: Plastic, metal, wood, glass, rubber, leather, textiles, bulk paint Dimensions: 36x26x32 inches Weight: 240 lbs 50 kV, 2 mA maximum Mo anode; 7, 17.5, 31 keV DCCs; SDD

6. Thermo Scientific Niton XL3t • Purchased in 2009 to evaluate side-by-side with M-XRF • Calibration modes • Metals (%) • Soil (mg/kg) • Filters (µg/filter) • Plastics (mg/kg) • Painted products (µg/cm2) • Reports >30 elements ≤2 minutes 3-8 mm spot size Dimensions: 9x9x4 inches Weight: <3 lbs 50 kV, 40 µA maximum Au anode; SDD

7. Lead in toys • Consumer Product Safety Improvement Act (CPSIA) of 2008 • New regulations for products intended for children <12 years old 2 µg/cm2

8. Reporting units for lead in paint • 90 mg/kg (ppm) is the CPSC limit required to demonstrate compliance with CPSIA • Basis in bio-kinetic model of lead exposure in children • Previous 600 mg/kg limit related to 300 µg Pb/day expected to keep BLL <40 µg/dL • 2 µg/cm2 is intended as a screening limit for small painted areas (<1 cm2 or 10 mg) • Industry consensus value, scientific basis uncertain • Appears widely used • 2 µg/cm2 ≅90 mg/kg??

9. ASTM/XOS Interlaboratory Study - 2010 • Goal - precision statement for ASTM F2853, a standard (CPSC approved) method for determination of lead in paint layers by M-XRF (HD-Prime) • “Repeatability” 26 mg/kg at 90 mg/kg • “Reproducibility” 35 mg/kg at 90 mg/kg • N = 9 labs: Wadsworth; NIST; 5 testing labs; Mattel; XOS • 40 test samples distributed • Bulk substrate CRM/RMs • Metal, glass, wood, plastics • Paint film on substrate RMs • 5 µm and 30 µm thickness • Retain samples for further assessment

10. Painted-surface RMs on HD-Prime Each of these samples (n=10) ND with the XL3t, 5 false negatives Reference 50 mg/kg HD-Prime 52±6 (4% bias) LOD (mg/kg) HD-Prime 17 Error bars ±SD, n=10

11. Comparing XRF area concentrations with mass fractions determined by AAS 30-µm paint on PVC FP Error bars ±SD, n=10

12. Assessment with SRM 2569 Lead Paint Films for Children’s Products • Released by NIST in 2011 • Certified in both mg/kg and µg/cm2 units LOD 16 mg/kg Does not report in mg/kg 1.158 g/cm3 22.9 µm LOD 0.13 µg/cm2 LOD 0.03 µg/cm2 Non-representative matrix n=10 Certified values in µg/cm2 are well below threshold

13. Lead in household paint

14. Screening paint chips with the XL3t • Ex-situ XRF could provide an alternative means of identifying LBP • Preliminary assessment completed using NIST Powdered Paint SRMs and routine samples received at Wadsworth Samples measured as received in plastic bag n=7, 60 s measurement time

15. Screening paint chips with the XL3t n=53 samples, 60 s measurement time

16. Conclusions & summary recommendations • Determination of lead content in paint on toys is a very difficult analytical problem • (+) XRF nondestructive nature & ability to test small areas/substrate • The XL3t is of limited use for determination of lead in painted toys, given false negatives for non-PVC substrates • Shows promise for ex-situ identification of LBP • Though the HD-Prime is approved for certifying compliance & reported no false negatives, quantitation at 90 mg/kg may be unreliable due to uncertainty in the “real world” LOD. • CPSC should consider reducing the 2 µg/cm2limit • NIST should produce SRMs more representative of painted toys • HUD/EPA should re-evaluate the 0.5 wt% limit as well as the screening methodologies for LBP

17. Future Work • Begin field evaluation of an M-XRF prototype intended for multi-element analysis • Characterizing the elemental content of materials in personal environment is important for some public health studies as it helpsidentify possible sources of exposure • R01 funding from NIH to incorporate into an ongoing epidemiological study • Focus on toxic elements • Compare performance to existing technology • Sensitivity, accuracy, fitness-for-purpose

18. XOS PEA β-prototype 4 minutes Large sample chamber Pb, As, Hg, Cd, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Se, Br, Rb Sr, Ag, Sn, Sb, Ba, Au, Tl, Bi Touch screen Dimensions: 15x18x18 inches Weight: 50 lbs 50 kV, 1 mA maximum Mo anode; 7, 17.5, 31 keV DCCs; SDD

19. Lead content in Indian spices Screening in bag, PEA 130±9 mg/kg 30% bias Turmeric Chili powder Error bars (XRF) ±SD, n=3, (ICP-OES & FAAS) ±10%, n=1

20. Screening of routine samples Herbal medicine product submitted as part of a lead-poisoning investigation • Identified possible additional health risk (<5 min) • Physician notified Error bars (XRF) ±SD, n=3, (ICP-OES) ±10%, n=1

21. Acknowledgements • Dr. Patrick Parsons, and the Laboratory of Inorganic and Nuclear Chemistry (LINC) at the Wadsworth Center, NYSDOH • John Orsini of LINC/NYSDOH • XOS • Funding: XOS SBIR from NIH NIEHS 5R44ES016689