Effectiveness of Engineering Controls for Airborne Lead Exposure during Renovation/Demolition of a Commercial Building

Abstract

Airborne lead exposure was evaluated during renova tion/demolition of a building that contained lead-based paint (LBP). During this work, different engineering and work practice controls were utilized for prevention and reduction of worker exposure to lead. These results sug gest that the highest exposure occurred when no engi neering or work practice controls were employed. Sum mary exposure levels under these conditions exceeded the Occupational Safety and Health Administration (OSHA) Permissible Exposure Level (PEL). When engi neering/work practice controls, in the form of negative air machine filtration (NAM) and wet methods were used, airborne concentrations of lead were well below the OSHA PEL (50 μg.m^-3) and action level (30 μg.m^-3). Employment of NAM without wet methods reduced arithmetic mean exposure below the OSHA PEL and geo metric mean below the OSHA action level. Occupational exposure concentration with NAM/wet methods was sta tistically lower when compared to no NAM/no wet meth ods and NAM/no wet methods. Exposure concentrations exhibited a nonnormal distribution. Comparison of with in and between-worker variability suggests that process/ environmental conditions (engineering/work practice controls) govern exposure. This study suggests employ ment of engineering and work practice controls for lead abatement and that process or environmental controls as compared to individual work practices/tasks are most important in controlling exposure. Study results support employment of NAM/wet method controls during reno vation or demolition of building materials that contain LBP.