MD, MPH,
and Mark R. Farfel, PhD
Chapter 2. Assessment and Remediation of Residential Lead Exposure
Managing Elevated Blood Lead Levels Among Young Children
15
Table 2.1. Summary of Recommendations for Assessment and Remediation of Residential
Lead Exposure
Make prompt and effective environmental management for children with EBLLs the
highest priority of all childhood lead poisoning prevention programs.
1. Conduct an environmental investigation for all children with blood lead levels
$ 20
Fg/dL, or persistently $15 Fg/dL. This investigation should include:
a. An inspection of the childs home and other sites where the child spends
significant amounts of time.
b. A history of the childs exposure.
c. Measurements of environmental lead levels, including at a minimum
i.
House dust;
ii. Paint that is not intact or is subject to friction;
iii. Exposed soil, especially in play areas;
iv. Other media as appropriate;
2. Ensure that interventions to reduce ongoing exposure:
a. Focus on control of current lead hazards.
b. Include prompt interim measures (e.g., house dust control by professional
cleaners) where appropriate, to rapidly reduce lead exposure.
c. Be performed in accordance with safe practices by trained workers to avoid
increasing lead exposure to occupants and workers.
d. Keep to a minimum on-site removal of intact leaded paint.
e. Replace or enclose building components when elimination of intact leaded paint
is performed.
f.
Include clearance testing following lead hazard reduction work to ensure that
lead levels are safe prior to a structure being re-occupied.
g. Include temporary occupant relocation or other measures to protect occupants
from exposure to leaded dust produced by lead hazard control activities.
h. Relocate children permanently to lead-safe housing if necessary to reduce their
lead exposure in a timely manner.
3. Encourage state and local governments to assess the effectiveness of their laws,
ordinances, housing codes, and enforcement structures in dealing with identified
lead hazards and to identify changes required to ensure that children are protected.
4. Promote the expansion of existing federal, state, and local subsidies to help finance
lead hazard control in economically distressed communities, and the creation of new
subsidies, if necessary. Chapter 2. Assessment and Remediation of Residential Lead Exposure
*
Throughout this document, the term paint will be used to refer to paint and, where appropriate, similar
surface-coating materials such as varnishes and stains. Paints and coatings manufactured since 1978 must contain
< 0.06% lead by weight. For testing of lead content in existing structures, the regulatory threshold for defining
lead-based paint is
$ 1 milligram of lead per square centimeter of paint film or $ 0.5 % lead by weight. These
standards, however, were based on the limitations of measurement techniques available when they were formulated
rather than on health considerations.
Managing Elevated Blood Lead Levels Among Young Children
16
Introduction
Recent research concerning lead exposure from leaded paint in the residential environment
has shown that some of the recommendations on managing lead hazards in the childs
environment made in the 1991 Centers for Disease Control and Prevention (CDC) guidance,
Preventing Lead Poisoning in Young Children,

need updating (1). In addition, a regulation to
control lead exposure from public drinking water (2), implemented during the 1990s, makes
possible a more focused approach to assessing that source than was previously recommended.
This chapter summarizes current knowledge concerning childrens lead exposure in the
residential environment, recommends interventions directed at reducing or eliminating lead
exposure, and provides information to guide state and local officials in developing and updating
policies and procedures for identifying and managing lead hazards in the residential environment
of children with elevated blood lead levels (EBLLs).
Detailed technical protocols for assessing and correcting lead hazards in a variety of
situations can be found in guidance developed by the Department of Housing and Urban
Development (HUD) for property owners, private contractors, and government housing agencies
(3). These are cited where appropriate.
Sources and pathways of residential lead exposure
Lead can be found in high concentrations in three media to which children may be directly
or indirectly exposed: paint, interior dust, and exterior soil or dust. This section discusses the
distribution of lead in these media and their relationships to one another and to blood lead levels
(BLLs) in children (Figure 2.1). Lead in tap water, generally a lower dose source of exposure, is
also addressed.
Paint
Although the addition of lead to residential paint and similar surface-coating materials, such
as varnishes and stains, was banned in 1978 (4), 74% of dwellings constructed prior to 1980
contain some leaded paint.
*
The amount of lead in paint is much greater in homes built before
1950 than in homes built later but prior to the ban on leaded house paint. For example, 90% of Chapter 2. Assessment and Remediation of Residential Lead Exposure
Managing Elevated Blood Lead Levels Among Young Children
17
dwellings built before 1940 have paint containing more than 1 mg/cm
2
of lead, compared with
62% of dwellings built from 1960 through 1979. The relative contrast is much greater for paint
containing more than 2 mg/cm
2
: 75% versus 18%, respectively (5). Direct and indirect exposure
of children to leaded paint that has deteriorated because of deferred maintenance is likely the
major factor in the increased risk for EBLL associated with poverty and living in older housing.
Data from the Third National Health and Nutrition Examination Survey (NHANES III) indicate
that the prevalence of EBLLs among children living in homes built before 1946 is five times
higher than that among children living in homes built after 1973 (most of which do not have
leaded paint) (6). Furthermore, for low-income children living in pre-1946 dwellings, the
prevalence of EBLLs is 16%, compared with 4% for middle-income children living in such
dwellings (6).
Although children may be exposed to lead from paint directly by ingesting paint chips (7),
they are more commonly exposed by ingesting house dust or soil contaminated by leaded paint
(8, 9). Federal law defines a leaded paint hazard as a condition in which exposure to lead from
lead-contaminated dust, lead-contaminated soil, or deteriorated leaded paint would have an
adverse effect on human health (10).
Lead contamination of dust or soil occurs when leaded paint deteriorates or is subject to
friction or abrasion (as on window sashes). In addition, lead can be dispersed when paint is
disturbed during demolition, remodeling, paint removal, or preparation of painted surfaces for
repainting. In a population-based study in Wisconsin, about two-thirds of children who had a
blood lead test lived in a home that had undergone some type of renovation, repair, or remodeling
work in the prior year. These children were at 1.3 times greater risk of having an EBLL than were
children not exposed to such activities (11). The risk was even higher among children living in
homes where certain practices, such as the removal of paint with heat guns, had been used.
Interior dust
Interior house dust can become contaminated with lead as the result of the deterioration or
disturbance of leaded paint, the tracking or blowing in of contaminated soil, and the fallout of
airborne lead particulate from industrial or vehicular sources. A simple visual inspection of older
homes can identify those in poor condition. The condition of leaded paint more accurately
predicts lead exposure than the lead content of paint by itself (12, 13). Older homes in poor
condition have much higher dust lead levels than older homes in good condition (Figure 2.2)
(14). The amount of lead in house dust, in turn, has a strong correlation with the BLLs of young
children (12, 13, 15, 16)

and is more predictive of BLLs in children than is the amount of lead in
house paint (13).

Lead levels in house dust can be measured either as a mass concentration (mass
of lead/mass of dust) or as surface loading (mass of lead per surface area sampled). The most
widely used sampling technique, in which a wipe sample is collected with commercially
available baby wipes (3), can determine only lead surface loading. However, this measure Chapter 2. Assessment and Remediation of Residential Lead Exposure
Managing Elevated Blood Lead Levels Among Young Children
18
predicts BLLs as well as or better than mass concentration (17). Lead loadings vary considerably
among the types of surfaces commonly tested, with levels on interior window sills and window
wells (the part of the window that receives the lower sash when closed) often being,
respectively, 1 and 2 orders of magnitude higher than those found on floors. Higher levels on
window components may reflect a combination of lead dust derived from friction and the
deterioration of leaded paint on the windows themselves and from the settling of airborne dust
from outside of the dwelling. Dust lead loading on all three surfaces (floors, windowsills, and
window wells) correlates with BLLs in children (12).
A recent statistical analysis of data from 12 studies relating lead in dust to BLLs in chi