Abstract
Lead (7439921) poisoning among construction workers renovating a previously deleaded bridge was studied. Lead based paint had been removed from the bridge by sand blasting several years before, followed by repainting with a nonlead based paint. Workers were now removing and replacing the concrete deck and portions of the steel infrastructure of the four lane bridge. Workers did not use engineering controls or respirators, change clothes, wash hands, or shower during the work day. Within the first 30 days on the site, several workers complained of symptoms, including headaches, stomach pain, irritability, and muscle aches. The workers were seen by an occupational medicine physician who diagnosed lead poisoning and initiated a worksite evaluation. Twelve of 44 tested workers had blood lead levels exceeding 20 micrograms/deciliter (microg/dl), with one exceeding 50microg/dl and two exceeding 40microg/dl. Zinc protoporphyrin (ZPP) levels were also analyzed, and had a geometric mean value of 28.9 microgram/gram hemoglobin. Intervention included a lead compliance program with provisions for exposure evaluation, training, hygiene, and engineering controls. Blood lead levels dropped significantly following intervention, while ZPPs did not. The authors conclude that deleading of bridges and other structures may fail to remove lead from inaccessible locations, and that construction contractors and workers should be prepared to evaluate and control any emissions potentially containing lead.
