February 15, 2013

Firing range lead exposure reduced with UW workplace health expertise

Environmental & Occupational Health

The speeding bullet isn’t the only danger to using guns. The inside core of the bullet is made of lead. When a gun is fired, lead dust and fumes are generated. That “smoke” in a smoking barrel can contain high concentrations of lead.

Researchers in the Department of Environmental and Occupational Health Sciences in the University of Washington School of Public Health have assisted gun ranges by evaluating their ventilation systems and testing their employees’ exposure to airborne lead levels.

Niels Noordhoek

Bullet shot from a revolver releases
smoke that contains lead.

The evaluations are part of the occupational health and safety consultations offered by the Field Research and Consultation Group to companies that request assistance. Consultants observe work practices, collect air and wipe samples, and make recommendations for controlling workplace exposures.

Firing ranges should have a well-designed and operating ventilation system, said Martin Cohen, director of the Field Research and Consultation Group and senior lecturer in environmental and occupational health Sciences. The ventilation system should capture and remove airborne lead to prevent deposits on surfaces. It also reduces exposures to lead, for those workers at the range, the public, and people in occupations that require gun practice and training as part of their jobs—namely, police officers and military personnel.

But designing and installing an effective ventilation system that works well in a firing range can be tricky.

Explained Cohen. “Usually the space is fairly tight. There are practical considerations for where you can put a duct system and it needs to be designed and operated properly.”

It’s also expensive, added Gerry Croteau, a research industrial hygienist with the Field Research and Consultation Group. He has evaluated ventilation systems  and monitored worker airborne lead exposures at several gun ranges.

If a workers’ eight-hour average airborne lead levels exceeds  the “action level” of 0.03 milligrams per cubic meter, the facility is required to comply with stringent regulations involving respiratory protection, ventilation controls, housekeeping and practices to keep the worker from leaving the facility with lead on their clothes or body. These regulations were promulgated by the federal Occupational Safety and Health Administration. In our state the regulations are enforced by—the Division of Occupational Safety and Health (part of the Department of Labor and Industries)..

Gun range employees typically don’t spend a lot of time on the actual firing range, with the exception of range cleaning and maintenance activities

Every day or two, the bullet casings and target remnants need to be cleaned off the range floor. Some ranges use soil or sand berms behind the target to stop the bullets. These also must be periodically cleaned.

Cohen said that the methods that the employer and workers use to clean and maintain the range are crucial to protecting the workers from lead exposure. If workers sweep, fine lead dust particles can become airborne and produce a respiratory exposure hazard.

“One best practice is to use a vacuum with a HEPA filter. It can keep the dust from becoming airborne during cleaning,” said Cohen. HEPA is an acronym for High-Efficiency Particulate Air.

Workers should wear a Tyvek suit, gloves, and a respirator while cleaning. Tyvek is a Dupont trademark for its protective, non-woven fabric. Regulations stipulate that work shoes and clothing are not allowed to be worn outside the facility  as lead laden clothing can potentially contaminate the home environment.

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