Executive Summary of EPA 747-R-99-001
for the report
Lead Exposure Associated with
Renovation and Remodeling Activities: Phase IV,
Worker Characterization and Blood-Lead Study of
R&R Workers Who Specialize in Renovation of
Old or Historic Homes
March 1999, (EPA 747-R-99-001)
The Residential Lead-Based Paint Hazard Reduction Act (Title X) required the U.S. Environmental Protection Agency (EPA) to conduct a study of lead exposure associated with renovation and remodeling activities (R&R Study). Information obtained from the R&R Study will be used to help determine which groups of workers require training, certification, or educational materials because of the potential lead exposure to themselves or to others resulting from the R&R activities that they perform. Three phases of the R&R Study, each comprising a separate and distinct data collection effort, have been completed. They include:
. Phase I, Environmental Field Sampling Study (EFSS). The EFSS was conducted to measure the airborne (breathing zone) lead levels and lead levels in settled dust resulting from several renovation and remodeling work activities.
. Phase II, Worker Characterization and Blood-Lead Study (WCBS). The WCBS was designed to assess the relationship between the conduct of R&R activities and lead exposure to the R&R workers who engaged in those activities. The WCBS collected questionnaire information and a blood sample for analysis from each of 581 R&R professionals.
. Phase III, Wisconsin Childhood Blood-Lead Study. The Wisconsin Childhood Blood-Lead Study was a retrospective case-control study designed to systematically examine the association between R&R activities and elevated blood-lead levels (?10 ?g/dL) among children.
This report presents the fourth Phase in this series of data collection activities. Phase IV closely resembles Phase II (WCBS) in design and functions as an extension of the earlier study. Whereas Phase II explored lead exposure among general R&R workers, Phase IV focused on individuals who worked extensively in older (pre-1940) or historic homes where the risk of lead exposure associated with R&R work is considered to be especially high. In addition to R&R professionals, homeowners of older or historic homes who reside in their homes while performing R&R activities themselves were included in Phase IV.
Study participants were recruited using several approaches. Newspaper advertising produced the greatest number of study subjects. In-person recruitment and personal referrals were also effective methods for identifying participants. In total, questionnaire information and blood samples were collected from 243 participants (161 workers and 82 homeowners) in three cities: Charleston, SC; Savannah, GA; and Baltimore, MD.
As was the case with Phase II, environmental samples were not collected as part of Phase IV. There were several reasons for this decision. Both phases were designed to be minimally intrusive to potential participants. Collection of environmental samples would have reduced the participation rates for these two studies, and clearly would have substantially increased the time and cost of conducting them.
The questionnaire results indicated that
1. Workers spent more time performing R&R than homeowners (on average 24 days and 14 days in the past 30 days respectively).
2. Both workers and homeowners spent time performing a variety of R&R activities. For both groups, a large amount of time was spent performing large structure removal and paint removal/surface preparation.
3. Despite the OSHA Lead in Construction Standard, only 23.7 percent of workers reported using a respirator in the last 30 days. Similarly, only 16 percent of homeowners used a respirator in the last 30 days. Homeowners and workers in every work group used a dust mask more frequently than any type of respirator (44.9 percent of workers and 29.6 percent of homeowners reported using dust masks).
4. Seventy-six percent of workers had not received any lead exposure training, and 67 percent of workers and 62 percent of homeowners had not received any educational materials on lead hazards (homeowners were not asked about training).
5. Over 75 percent of workers and homeowners reported using dry sanding/scraping to remove paint. Roughly 41 percent of workers reported using chemical stripping (37 percent of homeowners) and 32 percent of workers (31 percent of homeowners) reported using burning/torching/heat gun to remove paint.
The geometric mean blood-lead concentrations of study participants were 5.73 ?g/dL for workers and 4.45 ?g/dL for homeowners. Forty-nine out of the 243 study participants (20.2 percent) had blood-lead concentrations greater than 10 ?g/dL. Several participants (2.9 percent) had blood-lead concentrations greater than 25 ?g/dL, and three participants (all workers) had blood-lead concentrations above 40 ?g/dL.
Overall, the blood-lead data indicate that Phase IV study participants were more highly exposed to lead than the general R&R workers from Phase II (i.e., workers not necessarily working in historic or older homes). The geometric mean blood-lead concentration for workers in this study (Phase IV) was significantly higher than the geometric mean blood-lead concentration of workers in the WCBS (Phase II). On the other hand, the geometric mean blood-lead level for homeowners in Phase IV was not significantly different from that of workers in the WCBS. Perhaps most important, a significantly larger percentage of all participants (workers and homeowners) in Phase IV had elevated blood-lead levels than did workers in the WCBS. In general, the percentage of Phase IV participants with blood-lead levels above 10 ?g/dL, 15 ?g/dL, and 25 ?g/dL was about twice as high as the corresponding percentages for workers in the WCBS.
Statistical models were developed and fitted to the worker and homeowner data. These models were used to investigate the relationship between blood-lead concentrations and potential lead exposure associated with specific R&R activities. These models indicate that there is a significant relationship between the conduct of certain R&R activities and blood-lead concentrations. For homeowners, paint removal/surface preparation was the single target activity that explained the most variability in blood-lead concentrations. For workers, the models indicated that worker blood-lead concentrations were most strongly associated with the combined effects of the following: the number of days spent performing cleanup, the number of weeks spent performing paint removal/surface preparation, the number of weeks spent performing carpet removal, and the number of years in the R&R career where some time was spent replacing window or door casements. The total number of hours in the last 30 days and the number of weeks in the last 12 months that the homeowner spent performing paint removal/surface preparation were related to increased blood-lead concentrations. The number of hours and weeks spent performing general R&R were also related to increased blood-lead levels in homeowners.