Health hazard evaluation report: HETA-2002-0157-2887, City of Cleveland Heights, Cleveland Heights, Ohio.
In March 2002 the National Institute for Occupational Safety and Health (NIOSH) received a confidential request for a health hazard evaluation (HHE) from employees at the Dominic Tomaro Public Works Garage Complex in Cleveland Heights, Ohio. Several workers were concerned with a variety of possible hazards, including asbestos (specifically in the municipal waste transfer station), diesel exhaust in the city garage, and inoperable exhaust fans. Immediately after an opening conference on April 30, 2002, a walk-through of the Transfer Station and City Garage was conducted. On May 1, bulk and area air monitoring was conducted for asbestos, carbon monoxide (CO), and diesel exhaust. Eight bulk samples of insulation were collected from the Transfer Station and analyzed for asbestos. All of the samples contained more that 1% asbestos, with two bulk samples of damaged (friable) pipe insulation containing between 20% to 50% asbestos. The U.S. Environmental Protection Agency (EPA) considers any substance containing greater than 1% asbestos to be asbestos-containing material (ACM). The CO concentrations measured in the City Garage during the morning period (coinciding with the highest level of worker activity) averaged 4 parts per million (ppm), with the highest peak CO exposure at 73 ppm. These results were well below the NIOSH recommended exposure limit for CO of 35 ppm for an 8-hour time-weighted average (TWA) exposure and the NIOSH ceiling limit of 200 ppm. Diesel exhaust concentrations (measured as elemental carbon, EC) ranged from trace amounts (between 0.19 to 0.94 micrograms per cubic meter, g/m3) to 1.1 g/m3, well below the proposed American Conference of Governmental Industrial Hygienists' Threshold Limit Value of 20 g/m3 for diesel exhaust for up to an 8-hour TWA exposure. This NIOSH investigation found that a potential health hazard existed from the ACM in the insulation on walls, beams and piping in the Transfer Station. NIOSH, along with the EPA, does not consider removal of ACM as necessarily the best course of action, since improper removal can create a dangerous situation where none previously existed. Instead, an operations and maintenance (O&M) program for managing asbestos in place should be developed. The major program elements should include notification, surveillance, controls, work practices, record keeping, worker protection, and training. Although concentrations of CO and diesel exhaust in the City Garage were below applicable occupational exposure limits on the day of this evaluation, the general dilution ventilation should be increased (by replacing non-functioning wall exhaust fans) and the time that vehicles are allowed to idle in garage should be reduced.