Publishing their findings in the July/August 2002 edition of the American Industrial Hygiene Association's AIHA Journal, authors Susan R. Woskie et. al. examined worker exposure during various phases of the "Big Dig" project, including roadway demolition, slurry wall construction and utility relocation. The article, "Exposures to Quartz, Diesel, Dust, and Welding Fumes During Heavy and Highway Construction," reflects samples taken during 113 site visits between June 1994 and April 1999.
The authors said that more than three-quarters (77 percent) of the samples taken exceeded the ACHIH TLV for welding fume. Some 14 percent of the samples taken were over the proposed TLV for diesel exhaust, and sampling for silica exposure found 15 percent of the samples exceeded the OSHA PEL and 21 percent exceeded the NIOSH REL.
"The concern for cancers of the respiratory tract and the gastrointestinal and urinary systems suggests that it is time to broaden the traditional focus on the respirable fraction of crystalline silica, which was based on the association with silicosis," wrote the researchers.
They noted that 11 percent of the samples exceeded the TLV for fluoride, and 16 percent exceeded the TLV for manganese, adding, "Manganese exposures in welders have been associated with neurotoxic effects resulting in decreased motor function."