An evaluation of lead exposure among Midwest bridge renovation and demolition workers

Lead exposure among Midwestern construction workers in general, and bridge repair/renovation workers in particular, was analyzed using questionnaire responses, results from environmental samples collected from bridge renovation sites, and data available from the Occupational Safety and Health Administration (OSHA) workplace inspections.;Data from the Iowa Construction Workers Lead Exposure Survey indicate that there is relatively poor compliance with the OSHA Lead-in-Construction standard, and that workers in highway and bridge construction, as well as those engaged in renovation and demolition work, have higher blood lead levels and the potential for greater lead exposure than workers in other construction projects (p = 0.001 for Kruskal-Wallis nonparametric ANOVA). Availability of personal protective measures, medical surveillance, and engineering controls in all construction projects was very limited; industrial construction and lead abatement activities ranked highest in terms of the use and availability of lead exposure controls (p = 0.001 for Chi-square analysis).;Airborne lead concentrations ranged from non-detectable to approximately 500 mug/M3 as an 8 hour time-weighted average for workers at a Midwest bridge repair site, with torch cutting of metal generating the highest exposures (p = 0.043). Although this bridge had supposedly undergone a "de-leading" process before the renovation, significant lead exposure still occurred. Lead contamination of workers' clothes and automobiles was widespread, due to the limited availability of control measures.;An investigation into abrasive blasting at a second Midwest bridge renovation revealed that significant amounts of lead and particulate matter escaped from the blasting containment into the ambient environment during blasting operations. Personal air monitoring of painting inspectors showed that the blasting/blowdown procedure generates large amounts of lead-containing dusts, and that these dusts remain airborne for extended periods, even with the use of negative-pressure ventilation. Analysis of Occupational Safety and Health Administration workplace inspection data revealed that workers at bridge repair and renovation sites receive a disproportionate share of excessive lead exposures and that the midwest United States ranks highest among all regions of the country in severity of lead exposures.