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Lead Dust Standards, Window Replacement & Other Recent Developments

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Presentation on theme: "Lead Dust Standards, Window Replacement & Other Recent Developments"— Presentation transcript:

1 Lead Dust Standards, Window Replacement & Other Recent Developments
David E. Jacobs, PhD, CIH • 2014 Healthy Homes Conference Nashville, TN • May 2014

2 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)

3 Global Distribution of Burden of Disease Lead = 16th in DALYs (WHO 2002)

4 Evolution of Lead Exposure Pathway Analysis (Bornschein et al. 1986)

5 Pathways of Childhood Lead Exposure 1990s




9 Has the Lead Problem Already Been Solved?


11 US Childhood PbB Compared to “Natural” Background PbB
Bkgd=0.016 ug/dL (Flegal 1986)

12 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

13 How Much Lead Paint Is Left?
7.5 billion square feet interior 36.7 billion Total square feet 29.2 billion square feet exterior Source: HUD National Survey of Lead and Allergens, 2000

14 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

15 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

16 US Dust Lead Standard (1999 & 2001)
Set in 1999 – 2001, based on data from mid-1990s 40 µg/ft2 Floors 250 µg/ft2 Interior Window Sills

17 Dust Lead Standards Are they health-based? Are they attainable?
Blood Lead Level Probability of Exceedance Are they attainable? Can typical and high risk dwellings meet them over time? Are they measurable?

18 History of Floor PbD Standard
Bioavailable PbD fraction 200 µg/ft2 (Farfel et al. - Baltimore Late 1980s), based on PbB of 25 µg/dL Total Pb PbD 100 µg/ft2 (EPA Guidance, 1995) 40 µg/ft2 (HUD Std.1999) 40 µg/ft2 (EPA Std. 2001)


20 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

21 New Data (Cross-Sectional)
Floor GM = 1 µg/ft2 90th percentile (floor) < 10 µg/ft2 HUD National Survey 2000 & 2006 98% of homes have floor PbD <10 µg/ft2 NHANES/PbD Analysis Dixon et al 2009

22 Six-Year Followup of HUD Evaluation Study (Wilson et al. 2006
Six-Year Followup of HUD Evaluation Study (Wilson et al Env Res 102: )

23 12-Year Follow-up Shows Dust Lead Stays Low and All Lead Windows Should be Replaced


25 NHANES Empirical Dixon Findings: Going from 40 to 10 µg/ft2 yields an improvement from 52%>5 µg/dL to 24% A 50% improvement

26 Measurement Reporting limit today is 3 µg/wipe
(Cossa 2007, personal communication) Lower reporting limits feasible AAS, ICP, Graphite Furnace

27 Window Sill PbD from NHANES
If Floor PbD= 10 µg/ft2 Then Sill PbD= 100 µg/ft2

28 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)

29 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!

30 Lead Dust Panel EPA Science Advisory Board December 6, 2010

31 Overall Approach Log vs Linear at low levels
Target blood lead levels vs. incremental Comparison of empirical & biokinetic models

32 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

33 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.”

34 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

35 But because lead is a multi-media pollutant, the Agency should not expect a dust lead standard on its own to 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

36 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.”

37 “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 2012 CHPAC Letter

38 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.

39 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

40 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

41 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.

42 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.

43 Prevalence of Blood Lead Levels (PbB) Selected Levels 2007‐2010
Population Aged 1-5 Estimated 95% Confidence Intervals PbB ≥10 162,719 (45,173; 352,248) PbB ≥ 5 535,699 (316,289; 810,677) PbB 5‐9 372,979 (251,663; 517,561) Source: CDC National Health and Nutrition Examination Survey

44 Comprehensive Lead Education and Reduction Through Window Replacement CLEAR WIN
Surface & Health Outcome Baseline (100 units) One year (26 units) Percent Improvement Floors (ug/ft2) 8.5 5.4 36% Sills (ug/ft2) 149 20 87% Troughs (ug/ft2) 2593 114 96% Comfort in winter 54% 88% 63% Water & Dampness 80% 24% 70% Asthma Symptom Score 2.6 1.9 p=0.074

45 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


47 “Knowing is not enough; we must apply
“Knowing is not enough; we must apply. Willing is not enough; we must do.” —Goethe

48 Contact Information David Jacobs, PhD, CIH Research Director National Center for Healthy Housing Washington DC

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