Evidence of the Link Between Lead Paint and Lead Poisoning Historical Case Surveillance Data Environmental Correlate Studies Stable Isotope Ratios Lead-Based Paint as a Major Source of Childhood Lead Poisoning: A Review of the Evidence in Lead In Paint, Soil and Dust: Health Risks, Exposure Studies, Control Measures and Quality Assurance, Michael E. Beard and S.D. Allen Iske, Eds, American Society for Testing and Materials, Philadelphia, p. 175-187, 1995.
Options Permanent –Replace windows, doors, other building items –Enclose lead paint (new walls, siding) –Encapsulate lead paint (special long term coatings) –Remove lead paint using wet scraping, low-temperature heat guns, chemicals Short Term (Management) –Paint Stabilization –On-going Maintenance
Options (2) Dust Control –Friction & Impact Surfaces –Special Cleaning Bare Soil –Vegetation –Mulch –Removal
US Dust Lead Standard Floors = 40 ug/ft 2 Interior Window Sills = 250 ug/ft 2 Set so that less than 5% of children would develop a PbB above the intervention level (15 ug/dL) Set in 1999 Now widely perceived as being insufficiently protective New NCHH proposal –10 ug/ft 2 and 100 ug/ft 2 for floors & sills
Key US Lead Exposure Limits Ambient Air (old)1.5 ug/m 3 Ambient Air (new)0.1 – 0.3 ug/m 3 Settled Dust (Floors)40 ug/ft 2 10 ug/ft 2 (NCHH proposed) Settled Dust (Sills)250 ug/ft 2 Play Soil (bare)400 ppm Yard Soil (bare)1200 ppm Drinking Water15 ug/L New Housing Paint600 ppm (90) Existing Housing Paint1 mg/cm 2 or 5,000 ppm
Key US Lead Exposure Limits (2) Workplace Air (8 hrs)50 ug/m 3 Permissible 30 ug/m 3 Action Level Exterior Concrete (Guidance) 800 ug/ft 2 Blood (Occupational)30 ug/dL Blood (Advisory)10 ug/dL (some jurisdictions now at 5)
The Power of Surveillance and National Surveys Age of Residence, year built Poisoned Children (%) From the Third National Health and Nutrition Examination Survey (NHANES III), Phase 2, 1991-1994 National Average for all children (4.4% with Blood Lead Levels above 10 g/dL) African American Children Low Income Children All Children
Housing Surveillance Data: Where is the Remaining Lead Paint?
Dust Lead & Paint Lead: Ease of Contamination Current US definition of lead paint = 1 mg/cm 2 Sand a one square foot area, turn it into dust Spread the dust over a 10 ft x 10 ft room Resulting lead dust loading = 9,300 ug/ft 2 Current US Government Limit = 40 ug/ft 2
Lead Paint Protections in the US Health-based exposure standards for paint, dust or soil Standard inspection or abatement protocols Prohibited paint removal methods Laboratory QA/QC Performance criteria for paint XRFs
Lead Paint Protections (cont’d) Trained or licensed inspectorate or abatement work force Occupational standards to protect workers Training curricula Public education Disclosure of known lead paint hazards & no enforcement Funding to address hazards in low-income privately owned high risk housing
Important Elements of US Approach 1.Research on Exposure Pathways (Lead as multi-media pollutant) 2.National and Local Surveillance on both Health and Housing Data is Essential 3.Guidelines, Legislation, Regulation & Enforcement 4.Education & Market-Based Approaches 5.Articulation of National Plan 6.Subsidy and Enforcement Targeted to Highest Risk 7.Evaluation of Exposure Control 8.High Cost of the Reactive Approach