摘要: |
Lead and alkaline dust exposures were evaluated during the chemical stripping of lead-based paint from an overpass bridge. The chemical stripper, used at this site was an alkaline paste (Peel Away ST1, Dumond Chemical, Inc., New York, NY) consisting of calcium hydroxide (21%), magnesium hydroxide (16%), sodium hydroxide (9%), and the balance water and other nontoxic materials. Paint removal work was done at an overpass bridge that carried four lanes of traffic and spanned seven railroad tracks near a switching station. The removal method consists of spraying the alkaline paste on the painted surface, allowing it to react overnight, the scraping the decomposed paint and excess caustic from the steel surface. After the scraping process, the debris was cleaned from the area and the surfaces were abrasive blasted. This paint removal technique was evaluated by collecting and analyzing bulk sample of paint; personal breathing zone (PBZ) air samples of the caustic applicator, scrapers, rinser, and abrasive blast operators; and area air samples. Work practices and personal hygiene practices were also observed. |