Work and blood lead relationships among bridge workers.
NIOSH 2004 Mar; :1-163
OSHA's most recent lead in construction standard projected that a 4-fold reduction in air-lead concentration during certain work activities (i.e. from a typical value of 200 microg m-3 to 50 microg m-3) would avoid substantial illness among workers. However, the effectiveness of lead health protection programs that address requirements under this standard has remained largely unknown until the research presented in this project. This research characterizes the sources and pathways of airborne lead exposure during bridgework, develops an exploratory model and applies the model toward an analysis of data collected during a large-scale lead health protection intervention. Over 30 different tasks were identified that produce elevated levels of lead in the air (average values range from less than 30 microg m-3 to almost 10000 microg m-3). Blood lead levels among almost 2000 painting, ironwork, general craft and professional workers enrolled in a model lead health protection program designed to monitor and prevent workers from absorbing lead during these high-exposure tasks were summarized for years 1992 - 1995. For blasters and ironworkers, CRISP, which stands for Connecticut Road Industry Surveillance Project, maintained substantially lower blood lead levels in 1994 than levels found among workers with the same job title who conducted work outside of Connecticut during the same year. We incorporated the characteristics of bridgework that generates airborne lead, the components of CRISP and a previously published mass balance bio-kinetic model into a model named CONLIS, for CONstruction Lead Intake Simulation in order to derive lead dose from both environmental and biological measurements. We tested, validated and developed software to run the model and to systematically explore the influences on lead intake among workers from exposure and preventive techniques deployed during abrasive blasting activities. Our initial investigation found that a 100 fold preventive effect from Connecticut's lead health protection program. We also used the model to establish and test a simplified predictive model and to simulate conditions for planning programs and managing and exposure. Two scenarios illustrate that future production rates (abrasive blast time per month) would be restricted to 30% of the original production rate when workers are allowed to reach the limit of exposure. CONLIS represents an approach that could have a broad range of potential applications for effectively protecting workers.
Lead-poisoning; Lead-compounds; Lead-dust; Lead-fumes; Construction-workers; Construction-industry; Construction-materials; Painters; Painting; Paint-spraying; Abrasive-blasting; Abrasive-grinding; Occupational-health-programs
Division of Environmental Health Sciences, School of Public Health, 140 Warren Hall, MC 7360, University of California, Berkeley, Berkeley, CA 94720-7360
Final Grant Report
NTIS Accession No.
National Institute for Occupational Safety and Health
University of California, Berkeley, Berkeley, CA