S. Clark et al., THE RELATIONSHIP BETWEEN SURFACE DUST LEAD LOADINGS ON CARPETS AND THE BLOOD LEAD OF YOUNG-CHILDREN, Environmental geochemistry and health, 18(4), 1996, pp. 143-146
The final clean-up of residential lead abatement projects in federally
-supported housing, as well as in other housing in a number of states,
must meet surface dust lead clearance levels expressed as mu g of lea
d per square foot. These clearance levels were established because han
d-to-mouth ingestion of lead-contaminated dust is recognised as a majo
r pathway through which many children are exposed. A dilemma exists be
cause many floors in housing undergoing abatement are carpeted and the
established clearance levels are generally not recommended for use on
carpets. These clearance levels are also used as 'action levels' to d
etermine whether exposure reduction activities are needed. The US Envi
ronmental Protection Agency is currently in the process of issuing sta
ndards for hazardous levels of lead in interior dust and bare soil und
er Title X of the Housing and Community Development Act of 1992, 'The
Residential Lead-Based Paint Hazard Reduction Act of 1992'. An effort
to develop a potential surface dust lead clearance level for carpets w
as made using an existing vacuum dust collection method that has previ
ously been shown to be a reliable indicator of childhood lead exposure
. This method was designed for use on carpeted and non-carpeted surfac
es. Using data from the Cincinnati Soil Lead Abatement Demonstration P
roject, the suggested floor-dust lead level where an estimated 95% of
the population of children would be expected to have blood lead values
below the national goal of 10 mu g dL(-1), was more than an order of
magnitude lower than the current floor-dust lead clearance level of 10
80 mu g m(-2) (100 mu g ft(-2)). Further comparisons of blood lead and
carpet lead levels in other parts of the country should be performed
before a risk-based lead loading clearance level is established.