Health hazard evaluation report: HETA-2004-0016-2971, Lehigh Portland Cement Company, Union Bridge, Maryland.
On October 8, 2003, the National Institute for Occupational Safety and Health (NIOSH) received a request from the management of Lehigh Portland Cement Company in Union Bridge, Maryland, to conduct an evaluation of employee exposure to airborne dust. This request was made to ensure safe work conditions for employees after the company moved into a new facility. The evaluation was conducted on April 13 and 14, 2004. Full-shift personal breathing air zone samples for total and respirable dusts were collected from 19 employees over a 2-day period. In addition to particulate weight, total dust samples were analyzed for metal content, and respirable dust samples were analyzed for silica content. Area air samples were collected in five locations throughout the facility. In addition, bulk samples representing various types of dusts present at the facility were analyzed for metal and silica content. Five of the nineteen total dust samples exceeded the Mine Safety and Health Administration Permissible Exposure Limit of 10 mg/m3. The respirable dust samples did not exceed any exposure limits. In the total dust samples, aluminum, calcium, manganese, magnesium, titanium, sodium, and iron were present in quantifiable amounts. None of these metals exceeded any recommended or regulatory standards. Silica (quartz and cristobalite) was not present in any of the personal air samples. NIOSH investigators have determined that a health hazard exists at this facility due to overexposure to dust. This report contains recommendations to reduce worker exposure to the dust. This includes use of respirators in dusty areas.