Presentation on theme: "Lead Dust Standards, Window Replacement & Other Recent Developments"— Presentation transcript:
1Lead Dust Standards, Window Replacement & Other Recent Developments David E. Jacobs, PhD, CIH • 2014 Healthy Homes Conference Nashville, TN • May 2014
2Outline Are Current Lead Exposures High or Low? History of Lead Exposure ModelsConsiderations in Setting a PbD StandardHealth, Feasibility and Measurement CapabilityHistory of PbD standardsNew Recommended Standard from NCHH and Developments at EPA Science Advisory Board & EPA Children’s Health Protection Advisory CommitteeNew DataComprehensive Lead Education and Reduction Through Window Replacement (CLEAR WIN) & Implications for HUD Window Policy(Note: PbD = Lead in Dust, PbB = Lead in Blood)
3Global Distribution of Burden of Disease Lead = 16th in DALYs (WHO 2002)
4Evolution of Lead Exposure Pathway Analysis (Bornschein et al. 1986)
11US Childhood PbB Compared to “Natural” Background PbB Bkgd=0.016 ug/dL(Flegal 1986)
12Settled Dust Lead & Paint Lead Current definition of lead paint = 1 mg/cm2Sand a one square foot area into dustSpread the dust over a 10 ft x 10 ft roomResulting lead dust loading = 9,300 ug/ft2Current US Government Limit = 40 ug/ft2
13How Much Lead Paint Is Left? 7.5 billion square feet interior36.7 billion Total square feet29.2 billion square feet exteriorSource: HUD National Survey of Lead and Allergens, 2000
14Total Net Benefits of Lead Safe Window Replacement Pre-1940 Housing$5,092 x 11 million units with single pane lead contaminated windows = $56 billionPre-1960 Housing$1, 092 x 11 million units with single pane lead contaminated windows = $11 billionTotal = $67 billion
15Other Non-Monetized Benefits Direct Medical CareAvoided Special EducationAvoided Attention Deficit Hyperactivity DisorderSpecial Property MaintenanceStress on Parents & ChildrenPremature Mortality & Memory LossTreatment of dental caries associated with lead exposureLiver, kidney and other diseases associated with exposureAvoided Lead LitigationLead-associated criminal behavior costs
16US Dust Lead Standard (1999 & 2001) Set in 1999 – 2001,based on data from mid-1990s40 µg/ft2Floors250 µg/ft2Interior Window Sills
17Dust Lead Standards Are they health-based? Are they attainable? Blood Lead LevelProbability of ExceedanceAre they attainable?Can typical and high risk dwellings meet them over time?Are they measurable?
18History of Floor PbD Standard Bioavailable PbD fraction200 µg/ft2 (Farfel et al. - Baltimore Late 1980s), based on PbB of 25 µg/dLTotal Pb PbD100 µg/ft2 (EPA Guidance, 1995)40 µg/ft2 (HUD Std.1999)40 µg/ft2 (EPA Std. 2001)
20Existing PbD StandardExisting 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
21New Data (Cross-Sectional) Floor GM = 1 µg/ft290th percentile (floor) < 10 µg/ft2HUD National Survey2000 & 200698% of homes have floor PbD <10 µg/ft2NHANES/PbD AnalysisDixon et al 2009
22Six-Year Followup of HUD Evaluation Study (Wilson et al. 2006 Six-Year Followup of HUD Evaluation Study (Wilson et al Env Res 102: )
2312-Year Follow-up Shows Dust Lead Stays Low and All Lead Windows Should be Replaced
25NHANES Empirical Dixon Findings: Going from 40 to 10 µg/ft2 yields an improvement from 52%>5 µg/dL to 24% A 50% improvement
26Measurement Reporting limit today is 3 µg/wipe (Cossa 2007, personal communication)Lower reporting limits feasibleAAS, ICP, Graphite Furnace
27Window Sill PbD from NHANES If Floor PbD=10 µg/ft2Then Sill PbD=100 µg/ft2
28A Dust Lead Standard of <10 µg/ft2 (floors) and <100 µg/ft2 (sills) Protective – Vast majority (>95%) of children will have PbB < 10 µg/dLMeasurable - 3 times greater than lab detection limit (Flame AAS)Feasible – Long-term studies show most houses can comply using existing lead cleaning methodsNot A Burden – New evidence is that > 90% of pre-1978 homes are:< 10 µg/ft2 (floors)< 100 µg/ft2 (sills)
29Recommendations 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 possibleParents, contractors, risk assessors and others should keep Floor PbD <10 µg/ft2 and Sill PbD <100 µg/ft2 immediatelyLocal jurisdictions should consider adopting the NCHH recommended standardWe should act on what the science tells us!
31Overall Approach Log vs Linear at low levels Target blood lead levels vs. incrementalComparison of empirical & biokinetic models
32Linear 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 resultSupra-linear at low floor and sill dustSAB recommended running both models & IEUBK
33Conclusion: 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.”
34EPA’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
35But 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 standardEPA has not acted on its SAB 2010 report
36CHPAC 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 actionsRejected a proposed rule to require dust lead testing following renovation, consistent with HUD.No action on dust std2012 CHPAC Letter
38CHPAC 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.
39CHPAC 2012 Recommendations Collect data from Environmental Lead Proficiency Analytical Testing Program and assess feasibility for reliably measuring low environmental lead levelsAssess the feasibility of meeting lower residential dust lead exposure limits.New, evidence-based health protective lead dust standards
40CHPAC 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 breastfeedingCHPAC 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
41CHPAC 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.
42CHPAC 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.
43Prevalence of Blood Lead Levels (PbB) Selected Levels 2007‐2010 Population Aged 1-5Estimated 95% Confidence IntervalsPbB ≥10162,719(45,173; 352,248)PbB ≥ 5535,699(316,289; 810,677)PbB 5‐9372,979(251,663; 517,561)Source: CDC National Health and Nutrition Examination Survey
44Comprehensive Lead Education and Reduction Through Window Replacement CLEAR WIN Surface & Health OutcomeBaseline(100 units)One year(26 units)Percent ImprovementFloors (ug/ft2)8.55.436%Sills (ug/ft2)1492087%Troughs (ug/ft2)259311496%Comfort in winter54%88%63%Water & Dampness80%24%70%Asthma Symptom Score2.61.9p=0.074
45Implications for HUD Window Policy Data in this study and others show window replacement is highly effectiveCurrent HUD policy impedes window replacementHUD should encourage (not discourage) window replacement