A study was done of lead (7439921) exposure among construction workers based on blood lead tests reported to the Massachusetts Lead Registry in the first 2 years of its operation, between May 1991 and April 1993. Blood lead tests over 0.72 micromole per liter (umol/l) were reported to the Department of Labor and Industries and individuals with lead levels greater than 1.93umol/l were contacted. Registrants were grouped as deleaders (residential lead abatement workers), other construction workers, and nonconstruction workers. There were 381 individuals with a blood level greater than 1.93umol/l and 82% were due to occupational exposure. Sixty three percent of the occupationally exposed were construction workers. Deleaders comprised 60% of the lead exposed construction workers and bridge and house painters accounted for 36% of individuals occupationally exposed to lead. There were 49 people with blood levels of 2.9umol/l or greater and 39 were construction workers, 20 were bridge and house painters, and 17 were deleaders. Of the workers interviewed for this study, all of the deleaders reported that a blood lead test was part of an employer sponsored program, but only 38% of the construction workers and 78% of nonconstruction workers had blood tests as part of an employer sponsored program. In Massachusetts and Maryland, construction workers constituted a significantly larger proportion of registrants with occupational exposures than in California, New Jersey, New York, and Texas.