Health Hazard Evaluation Report, HETA-2000-0181-2841, Wire Rope Corporation of America, Sedalia, Missouri.
In March 2000, the National Institute for Occupational Safety and Health (NIOSH) received a confidential request from a group of employees to conduct a health hazard evaluation (HHE) at the Wire Rope Corporation of America (WRCA) in Sedalia, Missouri. The HHE request stated that some employees experienced symptoms of nose bleeds, eye irritation, and unspecified respiratory symptoms that were believed to be related to exposures to metal dust and asphalt fume at work. Employees were also concerned about hazardous noise levels, poor lighting, and lack of exhaust ventilation to control air contaminants. A site visit on June 14-16, 2000, included a walk-through inspection of the facility's processes and medical interviews. On June 28-29, 2001, personal breathing-zone (PBZ) and area air samples were collected for metal dust and asphalt fume. To measure asphalt fume, air samples were collected and analyzed for the total particulate, the benzene-soluble particulate fraction, and polycyclic aromatic compounds (PACs). Noise exposures and lighting levels were also measured. Six full-shift PBZ air samples showed exposures to metal dust that were less than 1 percent of the most stringent occupational exposure limit available. Six short-term air samples collected for asphalt fume (measured as total particulate) showed that utility workers' exposures ranged up to 3.2 milligrams per cubic meter (mg/m3), below the NIOSH 15-minute ceiling limit of 5 mg/m3. Air sampling for the benzene-soluble particulate fraction of asphalt showed a strander operator's time-weighed average (TWA) exposure as high as 0.8 mg/m3, a concentration which exceeded the American Conference of Governmental Industrial Hygienists' (ACGIH) time-adjusted Threshold Limit Value (TLV) of 0.25 mg/m3 for a 12-hour TWA concentration. Two utility workers' exposures of 0.3 mg/m3 and 0.4 mg/m3 also exceeded the 12-hour adjusted ACGIH TLV for benzene-soluble particulate. Although no occupational exposure limits are currently available for PACs as a group, area air sampling showed the most abundant subclass of PACs were those believed to be associated with irritative effects. A total of 15 workers were interviewed, including all three of the utility workers present during our site visit. The workers had complaints of headache, upper respiratory irritation, increases of allergy symptoms, cough, and dry eyes. The symptoms generally improve when the employees leave the work site. Interviewed employees noted that the majority of symptoms and complaints have decreased in frequency and severity following elimination of the scrap cutting and some descaling processes. Workers reported that current symptoms are frequently related to exposure to asphalt fume from the large lube holding tanks. The vast majority of workers at the WRCA are exposed to excessive noise levels; some up to 9 ½ times the allowable dose for a 12-hour work shift. All employees surveyed have noise exposures that require them to be included in a hearing conservation program. Illumination levels range from 8 to 76 foot-candles, which are generally less than the American National Standard Institute (ANSI) recommended range of 50 to 100 foot-candles for machining processes at WRCA. Workers who handle liquid asphalt are overexposed to asphalt fume (measured as benzene-soluble particulate). The majority of WRCA workers are exposed to excessive noise levels, and most areas of the plant are poorly illuminated. Interviewed workers complained of headache, upper respiratory irritation, increases of allergy symptoms, cough, and dry eyes. However, these employees have noticed a decrease in the frequency and severity of these symptoms and complaints since scrap cutting and some descaling processes have stopped. Workers also reported that current symptoms are frequently related to exposure to asphalt fume from the large lube holding tanks. Recommendations are offered to reduce exposures to asphalt fume and hazardous noise levels, and to improve lighting at work stations.
Hazards-Confirmed; Region-7; Respiratory-system-disorders; Respiratory-irritants; Pulmonary-system-disorders; Ears; Eye-disorders; Eye-irritants; Eyes; Eye-strain; Lighting; Lighting-systems; Particulate-dust; Particulates; Dusts; Metalworking; Metal-dusts; Asphalt-fumes; Aromatic-hydrocarbons; Polycyclic-aromatic-hydrocarbons