Analysis of Lead-Safe Weatherization Practices and the Presence of Lead in Weatherized Homes

Study Design

The National Center for Healthy Housing (NCHH), with funding from the U.S. Department of Energy's (DOE) Oak Ridge National Laboratory (ORNL) and support from Battelle, partnered with state weatherization programs in Rhode Island (RI) and Maryland (MD) and with local agencies in Indianapolis, Indiana (IN) to conduct a study of the effect of weatherization activities on levels of lead in settled dust in homes.

The study was divided into two smaller studies:

1. A study of dust-lead creation during four paint-disturbing activities (cutting holes in knee walls and ceilings to gain access to attics, repairing windows, replacing windows, and planing thresholds/installing weatherstripping on doors); and

2. A study of dust-lead dispersion during two activities (blower door tests and dense-packing of walls).

To be eligible for the study, dwellings had to be built before 1950, have one or more target weatherization activities planned, one or more painted windows and/or doors, and no children with elevated blood lead levels (above 15 micrograms per deciliter (µg/dL)) residing in the dwelling. Before studying any target activity, paint on components to be disturbed and studied was tested for lead using a portable x-ray fluorescence (XRF) instrument. Only houses which had lead-based paint at 1.0 milligram per square centimeter (mg/cm²) or greater on one or more study-specified surfaces were eligible.

A total of 58 dwellings were successfully enrolled. To the extent possible, weatherization activities were conducted as they routinely would have been in the absence of the research study, and residents were not required to vacate homes during weatherization work or study data collection. For the dust-lead creation study, dust wipe samples were collected on floors at four stages: before worksite preparation, after the work but before removal of containment, after removal of containment, and after final cleanup. For two of the four dust creation activities (window repair and window replacement), dust samples from window sills and troughs were also collected before and after the activities were completed. For the dust dispersion study, dust wipe samples were taken from specified surfaces (e.g., floors and sills) before the dust dispersion activity and, after the activity was completed, from sheeting placed over each sample location.

The dust lead loadings set by EPA for abatement clearance with single-surface settled dust wipe samples were considered to be the relevant comparison values for sample results in this report. These comparison values were 40 micrograms per square foot (µg/ft2) for floors, 250 µg/ft2 for window sills, and 400 µg/ft2 for window troughs. Compliance with EPA clearance standards is not technically required in weatherization work.

Conclusions

The results of this study indicate that levels of leaded dust created by typical weatherization work in older housing with lead-based paint are likely to be well above EPA clearance levels, and therefore pose a substantial risk to children. Study findings affirm the need for areas to be cleaned after containment is removed.

GM floor dust lead loadings measured after final cleaning was done were not significantly different from those measured before work began, while geometric mean window sill and trough dust lead loadings were significantly lower after work was done. When viewed through these measures of central tendency, these data indicate that the current work practices examined in this study have either a positive or generally little impact on potential lead dust exposures. However, despite the decreases observed between pre-work and post-final cleaning, of the samples that exceeded comparison values after final cleaning, dust lead loadings for 70%, 40%, and 18% of floor, sill, and trough samples, respectively, showed an increase in dust lead loadings from pre-work to post-final cleaning. Of the pre-work samples that were less than comparison values, post-final cleaning dust lead loadings for 29% and 60% of floor and sill samples, respectively, exceeded comparison values after final cleaning. Analysis of the study data indicated that the higher the dust lead loadings remaining on floors after containment is removed but before cleanup is performed, the higher the post-final cleaning floor dust lead loadings. This finding, in conjunction with the finding that substantial amounts of lead dust are created during the work activity itself, suggests that contractors need to exercise care when removing containment and need to more thoroughly clean dust creation areas after containment is removed.

Other activities were observed during the weatherization work and field data collection, including movement of residents, their pets, and movement of workers through sample areas. These influences may have impacted results, but it was not possible to quantify the impact, if any, of these activities on study results because field investigators reported on these other activities for only a few of the study dwellings.

The dust dispersion findings are similar to an earlier Cavallo study which suggested that dust dispersion activities such as blower door tests can increase dust lead loadings, but the change is not large enough to trigger EPA action levels (Cavallo 2000). When EPA action levels were exceeded, the dust lead loadings were generally of concern prior to the test. The dust dispersion results for floors suggest that in an older home with deteriorated lead-based paint, workers must use caution when performing dust dispersion activities. For example, alternative engineering controls could be used such as positive pressure for blower door testing.

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