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Release: Sept. 15, 1999

Lead exposure still a problem for construction workers, UI study finds

IOWA CITY, Iowa -- Lead exposure continues to be a problem for some workers in the construction industry, according to University of Iowa researchers who studied workers in Iowa and Illinois.

From 1994 to 1996, UI investigators, led by Stephen J. Reynolds, Ph.D., associate professor of occupational and environmental health, interviewed and collected blood samples from 459 union members from trade groups of painters, plumbers/pipefitters, ironworkers, laborers and electricians in the two states. The goal was to characterize the prevalence of blood lead concentrations by construction trade and to identify risk factors for lead exposure among these workers.

"It's been known for some time that lead is a significant health problem in the construction industry," Reynolds said. "Our study is one of the few to look at the whole population of workers from these trade groups, not just the workers who we already knew were having problems with lead exposures."

Among all the construction workers involved in the study, the researchers found an average blood lead level of 4.7 micrograms of lead per deciliter (dL) of blood. This is only slightly higher than the U.S. national average of 3 micrograms per dL. However, differences were found between certain trade groups. Blood lead levels among laborers (an average of 7.6 micrograms per dL) and painters (an average of 5.9 micrograms per dL) were highest, while levels among electricians (an average of 2.4 micrograms per dL) were lowest.

"The findings were in line with what we expected," Reynolds said. "Several of these trades involve projects that put workers at greater risk. Laborers, for example, reported performing duties such as median cutting, blow-off of lead-containing dust from exposed beams and cleanup during renovation of bridges. Each of these activities would increase their risk of exposure."

The researchers found that elevated blood lead levels were associated with the type of work performed, especially bridge renovation, residential remodeling and activities that included welding, cutting or rivet busting.

Information about potential risk factors outside the workplace also was collected. More than 325 of the study subjects reported owning homes built before 1980 and having done remodeling which included paint removal, plumbing and soldering or welding. Hobbies with a potential for lead exposure -- such as stained glass, riflery/shooting and casting or smelting lead -- also were identified as important risk factors.

Despite the workers having a higher potential for exposure, Reynolds and his colleagues found that the blood lead levels of workers doing lead abatement projects were among the lowest in the study. These workers knew what the risks were and how to protect themselves, Reynolds said. This suggests that training, implementation of engineering controls and proper use of protective equipment such as respirators are effective in controlling lead exposure, he said.

In 1993 the Occupational Safety and Health Administration (OSHA) reduced its standard for permissible airborne lead exposure in the construction industry. At the time, OSHA also released provisions that included requirements for employer-laundered work clothing, shower and change facilities, and employee training on the hazards of lead. These provisions are required only for workers with airborne lead exposures exceeding the OSHA standard. The researchers reported that these provisions are seldom met; in general, occupational health and safety practices in the construction industry remain poor.

Lead exposure among construction workers is still a problem, but it's preventable, Reynolds said.

"Prevention depends on education, awareness and training of workers, and controls within the workplace," he said. "Construction is a tough environment to control. It's not like an industrial setting, where everything is enclosed and easier to deal with. But there are some things that can be done to protect this workforce and, by extension, protect their families from secondary exposure."

One important intervention, he said, is to make lead exposure controls part of construction project specifications before contracts are bid.

The study results were published in the August 1999 issue of the American Journal of Industrial Medicine.

NOTE TO EDITORS: Stephen Reynolds, Ph.D., can be reached at (319) 335-4212.