Cincinnati, OH: U.S. Department of Health and Human Services, Public Health Service, Centers for Disease Control and Prevention, National Institute for Occupational Safety and Health, HETA 96-0200-2799, 2000 Jun; :1-22
At the request of the Rhode Island Department of Health (RI DOH), we evaluated worker lead exposures during U.S. Department of Housing and Urban Development (HUD)-funded residential lead hazard reduction in Rhode Island. RI DOH was concerned that workers might be unnecessarily wearing respirators and protective clothing during various tasks. The predominant work tasks in lead hazard reduction work have changed as, over the past several years, HUD has shifted the emphasis of its national program. Participating contractors are performing less on-site removal of lead-based paint (LBP) and more component replacement and lead hazard reduction, i.e., replacement and renovating structures with the existing LBP left in place. The National Institute for Occupational Safety and Health (NIOSH) evaluated worker lead exposures during various tasks at 20 homes undergoing lead hazard reduction from 1996-1998. The study included task-based and full-shift air monitoring, measurement of the lead contamination in workers’ vehicles, and a review of the medical monitoring data reported to RI DOH. Results for workers’ full-shift airborne lead exposures (PbA) were highly variable, ranging from 1.5 to 1100 micrograms per cubic meter (:g/m3 , 20 samples). The maximum exposure was for dry scraping. The geometric mean (GM) full-shift lead exposure was 74 :g/m 3 among workers who performed any scraping during the work shift. One hundred fifty-two task-based samples were obtained for 11 task categories; most of the samples were for interior work (average time 139 minutes). Task-based PbA exposures were highly variable, ranging from 0.17 to 2000 :g/m3 . The GM PbA exposures by task ranged from 1.3 :g/m3 (yard work) to 150 :g/m3 (dry scraping). Within-task variability was high; in spite of this variability, task category was highly associated with logged PbA exposure (one-way ANOVA p <0.0001). Dry scraping and wet scraping tasks, which did not differ significantly, had the highest GM exposures. The actual full-shift exposures, which were obtained for a few single tasks, were generally similar to the GM exposures for the corresponding task-based samples. Four of the 11 tasks evaluated had estimated full-shift exposures above the Occupational Safety and Health Administration permissible exposure limit (PEL, 50 :g/m3 ): dry scraping, wet scraping, mixed surface prep, and caulking. It is likely that high levels during caulking represented collateral exposures from other dustgenerating work in the houses. Estimated full-shift exposure for the other seven tasks, including painting, removal, replacement, cleaning, wet demolition, yard work, and set-up, were below the PEL. Relatively high lead dust accumulations were found on workers’ hands. Lead contamination levels on the floors in workers’ vehicles were high compared to a nonworker comparison group, suggesting that lead contamination may be carried into the vehicles from the work area. Among workers who had blood lead level (BLL) results reported, the results indicated that this group had higher BLLs than the general population, and 38% of workers and site supervisors had BLL results at or above 25 micrograms per deciliter. The results of this evaluation indicate that some changes in the contractors’ respiratory protection programs should be made. While the respirators provided to workers (half-mask air-purifying respirators with a protection factor of 10) were appropriate for some of the tasks, a higher protection factor respirator is needed for wet or dry scraping tasks, as performed by participating contractors. Respirators should not be routinely required for the low hazard tasks, such as removal, replacement, cleaning, yard work, and set-up. Worker lead exposures during various lead hazard reduction tasks were highly variable. On average, lead exposures during dry scraping, wet scraping, mixed surface prep, removal, and caulking tasks were hazardous. Average lead exposures for removal, replacement, cleaning, wet demolition, yard work, and set-up tasks were below the PEL. Reported blood lead monitoring results indicated occupational exposure to lead, and that some licensed personnel, particularly site supervisors, had hazardous exposures. Hand surface levels indicated the potential for ingestion of lead, and lead contamination of workers’ vehicles was measured. Recommendations are provided in this report to help prevent hazardous worker exposures to LBP.