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)

Pathways of Childhood Lead Exposure1990s

Has the Lead Problem Already Been Solved?

US Childhood PbB Compared to “Natural” Background PbB

1994 2002 Bkgd0

0.5

1

1.5

2

2.5

3

Mean 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

How Much Lead Paint Is Left?

Source: HUD National Survey of Lead and Allergens, 2000

7.5 billion square feet

interior29.2

billion square feet

exterior

36.7 billion Total square

feet

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

US Dust Lead Standard(1999 & 2001)

Set in 1999 – 2001, based on data from mid-

1990s

40 µg/ft2Floors

250 µg/ft2Interior

Window Sills

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 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)

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

New Data (Cross-Sectional)

• Floor GM = 1 µg/ft2

• 90th percentile (floor) < 10 µg/ft2

HUD National Survey2000 & 2006

• 98% of homes have floor PbD <10 µg/ft2

NHANES/PbD Analysis Dixon et al 2009

Six-Year Followup of HUD Evaluation Study(Wilson et al. 2006. Env Res 102: 237-248)

12

-Year

Follow

-up

Sh

ow

s D

ust

Lead

Sta

ys

Low

an

d A

ll L

ead

Win

dow

s S

hou

ld b

e

Rep

laced

Figure 2: Adjusted geometric mean sill dust lead loading by window replacement group from pre-intervention to 12-years post-

intervention

-1 0 1 2 3 4 5 6 7 8 9 10 11 12

Years Post-Intervention

Du

st L

ead

Lo

adin

g (

µg/f

t2)

All Replacement Partial Replacement Non-Replacement

250

400

10

100

50 52

33

25

NHANES Empirical

Dixon Findings:

Going from 40 to 10

µg/ft2 yields an

improvement from 52%>5 µg/dL to 24%

A 50% improveme

nt

Measurement

Reporting limit today is 3 µg/wipe (Cossa 2007, personal communication)

Lower reporting limits feasible AAS, ICP, Graphite Furnace

Window Sill PbD from NHANES

If Floor PbD=

10 µg/ft2

Then Sill PbD=

100 µg/ft2

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!

EPA Science Advisory BoardDecember 6, 2010

Lead Dust Panel

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 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

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.”

•“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

CH

PA

C L

ett

er

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 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

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

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

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

END THE DUTCH BOY’s LEAD PARTY

“Knowing is not enough;

we must apply.

Willing is not enough; we must do.”

—Goethe

Contact Information

David Jacobs, PhD, CIHResearch DirectorNational Center for Healthy HousingWashington DC

djacobs @nchh.orgwww.nchh.org