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Lead Dust Standards, Window Replacement & Other Recent Developments. David E. Jacobs, PhD, CIH • 2014 Healthy Homes Conference Nashville, TN • May 2014. Outline. Are Current Lead Exposures High or Low? History of Lead Exposure Models Considerations in Setting a PbD Standard
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Lead Dust Standards, Window Replacement & Other Recent Developments David E. Jacobs, PhD, CIH • 2014 Healthy Homes Conference Nashville, TN • May 2014
Outline • Are Current Lead Exposures High or Low? • History of Lead Exposure Models • Considerations in Setting a PbD Standard • Health, Feasibility and Measurement Capability • History of PbD standards • New Recommended Standard from NCHH and Developments at EPA Science Advisory Board & EPA Children’s Health Protection Advisory Committee • New Data • Comprehensive Lead Education and Reduction Through Window Replacement (CLEAR WIN) & Implications for HUD Window Policy • (Note: PbD = Lead in Dust, PbB = Lead in Blood)
Global Distribution of Burden of Disease Lead = 16th in DALYs (WHO 2002)
Evolution of Lead Exposure Pathway Analysis(Bornschein et al. 1986)
US Childhood PbB Compared to “Natural” Background PbB Bkgd=0.016 ug/dL (Flegal 1986)
Settled Dust Lead & Paint Lead • Current definition of lead paint = 1 mg/cm2 • Sand a one square foot area into dust • Spread the dust over a 10 ft x 10 ft room • Resulting lead dust loading = 9,300 ug/ft2 • Current US Government Limit = 40 ug/ft2
7.5 billion square feet interior • 29.2 billion square feet exterior How Much Lead Paint Is Left? • 36.7 billion Total square feet Source: HUD National Survey of Lead and Allergens, 2000
Total Net Benefits of Lead Safe Window Replacement • Pre-1940 Housing • $5,092 x 11 million units with single pane lead contaminated windows = $56 billion • Pre-1960 Housing • $1, 092 x 11 million units with single pane lead contaminated windows = $11 billion • Total = $67 billion
Other Non-Monetized Benefits • Direct Medical Care • Avoided Special Education • Avoided Attention Deficit Hyperactivity Disorder • Special Property Maintenance • Stress on Parents & Children • Premature Mortality & Memory Loss • Treatment of dental caries associated with lead exposure • Liver, kidney and other diseases associated with exposure • Avoided Lead Litigation • Lead-associated criminal behavior costs
Dust Lead Standards • Are they health-based? • Blood Lead Level • Probability of Exceedance • Are they attainable? • Can typical and high risk dwellings meet them over time? • Are they measurable?
History of Floor PbD Standard • BioavailablePbD fraction • 200 µg/ft2 (Farfel et al. - Baltimore Late 1980s), based on PbB of 25 µg/dL • Total PbPbD • 100 µg/ft2 (EPA Guidance, 1995) • 40 µg/ft2 (HUD Std.1999) • 40 µg/ft2 (EPA Std. 2001)
Existing PbD Standard • Existing standard protects 95% of children from developing a PbB> 15 µg/dL (from pooled analysis) • In 1997, average lab reporting limit was about 25 µg/wipe (using flame AAS) • Typically regulatory standards are set at least 3 to 10 times above detection limits, to ensure reliability of measurements
Six-Year Followup of HUD Evaluation Study(Wilson et al. 2006. Env Res 102: 237-248)
12-Year Follow-up Shows Dust Lead Stays Low and All Lead Windows Should be Replaced
NHANES Empirical Dixon Findings: Going from 40 to 10 µg/ft2 yields an improvement from 52%>5 µg/dL to 24%A 50% improvement
Measurement • Reporting limit today is 3 µg/wipe • (Cossa 2007, personal communication) • Lower reporting limits feasible • AAS, ICP, Graphite Furnace
A Dust Lead Standard of <10 µg/ft2 (floors) and <100 µg/ft2 (sills) • Protective – Vast majority (>95%) of children will have PbB < 10 µg/dL • Measurable - 3 times greater than lab detection limit (Flame AAS) • Feasible– Long-term studies show most houses can comply using existing lead cleaning methods • Not A Burden – New evidence is that > 90% of pre-1978 homes are: • < 10 µg/ft2 (floors) • < 100 µg/ft2 (sills)
Recommendations • EPA should revise the standard • EPA should be required to periodically review the science, as it does for NAAQS and other lead standards; • PbD should be kept as low as possible • Parents, contractors, risk assessors and others should keep Floor PbD <10 µg/ft2 and Sill PbD <100 µg/ft2 immediately • Local jurisdictions should consider adopting the NCHH recommended standard • We should act on what the science tells us!
Lead Dust Panel EPA Science Advisory Board December 6, 2010
Overall Approach • Log vs Linear at low levels • Target blood lead levels vs. incremental • Comparison of empirical & biokinetic models
Linear vs log-log • “EPA considered the Dixon et al. (2009) log linear regression model linking log blood lead to log floor dust and log sill dust (“log-log model”) not to serve its needs” • EPA used non-linear modeling, obtained similar result • Supra-linear at low floor and sill dust • SAB recommended running both models & IEUBK
Conclusion: Two Views • “The results of the analyses…confirm that both the empirical and biokinetic models predict that large proportions (17–99 percent) of young children would have blood-lead levels above all three target levels (1, 2 and 5), even if the standards were set at loading levels far less than the current values.”
EPA’s Proportion of Children > 5ug/dL QL Central Tendency Model shows that there is a 30% improvement if floors go from 40 to 10 and sills are at 50
But because lead is a multi-media pollutant, the Agency should not expect a dust lead standard on its ownto achieve such levels. • Using target blood lead levels of 1 ug/dL and 2.5 ug/dL should be retained using incremental, not target approach. • EPA should focus on the likely improvements of a lower dust lead standard • EPA has not acted on its SAB 2010 report
CHPAC Children’s Health Protection Advisory Committee • 2 Letters to EPA Administrator on Lead (2012 & 2013) • “CHPAC is concerned that both Congress and this Administration must continue—not abandon—the battle to protect children from lead poisoning.” • As a leader in children’s health protection, your immediate and urgent attention to CHPAC’s recommendations is needed. • The US Centers for Disease Control and Prevention (CDC) lead poisoning prevention program for 2012 has been largely eliminated and CHPAC believes EPA and US Housing and Urban Development (HUD) programs have inadequate and increasingly fewer resources.”
2012 CHPAC Letter • “EPA’s recent lead poisoning prevention efforts have been wanting, mainly due to inadequate resources.” • Few enforcement RRP actions • Rejected a proposed rule to require dust lead testing following renovation, consistent with HUD. • No action on dust std
CHPAC 2012 Recommendations • CHPAC recommends that EPA revise its Integrated Exposure Uptake Biokinetic (IEUBK) model for estimating children’s blood lead levels associated with different and multiple exposure pathways. • CHPAC recommends that EPA adopt an incremental approach to specifying target blood lead levels.
CHPAC 2012 Recommendations • Collect data from Environmental Lead Proficiency Analytical Testing Program and assess feasibility for reliably measuring low environmental lead levels • Assess the feasibility of meeting lower residential dust lead exposure limits. • New, evidence-based health protective lead dust standards
CHPAC 2012 Recommendations • CHPAC recommends that EPA identify emerging sources of lead exposure to children and women who are or may become pregnant or who are breastfeeding • CHPAC recommends that EPA work to eliminate production of residential lead-based paint and the production of other sources of lead exposure in other countries, with UN and WHO
CHPAC 2012 Letter Conclusion • We have the knowledge and ability to ensure our children do not suffer from lead poisoning, which is entirely preventable. • Our goal to protect children from lead has not yet been achieved, and the problem remains large. • CHPAC urges you to continue the campaign to end childhood lead poisoning.
CHPAC 2013 Letter Recommendations • Establish new goals for childhood lead poisoning, because the nation did not meet the 2010 goal; • EPA’s outreach, education, training and enforcement strategies should incorporate the new CDC reference blood lead value; • EPA should regulate lead‐contaminated imports into the US and exports from the US, • Act to reduce lead exposures globally (UN and WHO). • New research on technologies to determine low lead levels in environmental media.
Prevalence of Blood Lead Levels (PbB)Selected Levels 2007‐2010 Source: CDC National Health and Nutrition Examination Survey
Comprehensive Lead Education and Reduction Through Window Replacement CLEAR WIN
Implications for HUD Window Policy • Data in this study and others show window replacement is highly effective • Current HUD policy impedes window replacement • HUD should encourage (not discourage) window replacement
“Knowing is not enough; we must apply. Willing is not enough; we must do.” —Goethe
Contact Information David Jacobs, PhD, CIH Research Director National Center for Healthy Housing Washington DC djacobs @nchh.org www.nchh.org