Lead Dust Standards, Window Replacement &
Other Recent Developments
David E. Jacobs, PhD, CIH • 2014 Healthy Homes Conference Nashville, TN • May 2014
Outline

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Are Current Lead Exposures High or Low?
History of Lead Exposure Models
Considerations in Setting a PbD Standard

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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 Exposure
1990s
Has the Lead Problem Already
Been Solved?
US Childhood PbB Compared to
“Natural” Background PbB
3
2.5
2
1.5
Mean PbB
1
0.5
Bkgd=0.016 ug/dL
0
1994
2002
Bkgd
(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?
7.5 billion
square feet
interior
29.2 billion
square feet
exterior
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




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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/ft2
Floors
250 µg/ft2
Interior
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)
HUD National Survey
2000 & 2006
• Floor GM = 1 µg/ft2
• 90th percentile (floor) < 10 µg/ft2
NHANES/PbD Analysis
Dixon et al 2009
• 98% of homes have floor PbD <10 µg/ft2
Six-Year Followup of HUD Evaluation Study
(Wilson et al. 2006. Env Res 102: 237-248)
400
Dust Lead Loading (µg/ft2)
12-Year Follow-up Shows Dust Lead Stays Low
and All Lead Windows Should be Replaced
Figure 2: Adjusted geometric mean sill dust lead loading by window
replacement group from pre-intervention to 12-years postintervention
250
100
52
50
33
25
10
-1
0
1
2
3
4
5
6
7
8
9
10
11
Years Post-Intervention
All Replacement
Partial Replacement
Non-Replacement
12
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
Window Sill PbD from NHANES
If Floor PbD=
Then Sill PbD=
10 µg/ft2
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


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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

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Log vs Linear at low levels
Target blood lead levels vs. incremental
Comparison of empirical & biokinetic models
Linear vs log-log

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“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

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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


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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

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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

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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
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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
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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

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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


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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, CIH
Research Director
National Center for Healthy Housing
Washington DC
djacobs @nchh.org
www.nchh.org