The purpose of this study--which is part of a larger evaluation of Maryland's lead law (House Bill 760)--was to investigate the relationship, if any, between dust lead loading results for composite samples and single surface samples collected from similar locations, and to determine if similar conclusions concerning the success or failure of a unit's lead hazard reduction treatments could be reached using either composite or single surface sample results. Post-intervention composite and average single surface dust lead loading results for samples collected from the bare floors of 94 Baltimore housing units were first compared with each other. Then both sets of results were compared with several Federal and state abatement clearance standards and guidance levels to determine if similar conclusions concerning the "passing" or "failing" of a unit could be reached using either sampling method. Plots of composite versus average single surface results suggest that these two sampling methods are not strongly correlated. Comparison of each sampling method's results with clearance standards and guidance levels indicates that composite sampling tends to under-report floor dust lead loading values; therefore, when composite results are compared with clearance standards, fewer units appear to "fail" clearance. This finding suggests that existing clearance standards and guidance levels may be valid only for single surface samples. Separate standards may need to be established if composite sampling is to be routinely used for clearance dust testing upon completion of lead hazard reduction treatments.
Learning Objectives: This presentation illustrates the poor correlation of composite versus single surface dust lead loading results and shows that, dut to the potential for composite results to under-report dust lead loadings, separate clearance standards may be needed if composite samples are routinely collected. Participants can use this information as an aid when developing or reviewing sampling plans and other data collection efforts. Information may also aid in policy review and in the development of clearance standards and guidance values
Keywords: Lead, Data Collection
Presenting author's disclosure statement:
Organization/institution whose products or services will be discussed: None
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.