Health hazard evaluation report: HETA-99-0068-2784, United States Postal Service, Mail Processing and Distribution Center, Orlando, Florida.
In January 1999, the National Institute for Occupational Safety and Health (NIOSH) received a health hazard evaluation (HHE) request from employees of the United States Postal Service, Orlando to conduct an HHE at the Orlando Mail Processing and Distribution Center (OMPDC), Orlando, Florida. Employees requested an evaluation of worker exposure to paper dust, exhaust from trucks, and low oxygen levels, and an evaluation of the heating, ventilating, and air conditioning (HVAC) systems. The primary process/task associated with paper dust exposures is machine mail sorting and the cleaning of machines by blowing paper dust from the machines (termed "blowout"). In the request, the employees listed concerns regarding inhalation exposures and the indoor environment resulting in dry throat/eyes/nose, migraines, sinus headaches, asthma, bronchitis, and pneumonia. On March 16-18, 1999, NIOSH investigators performed a walkthrough survey of the worksite and met with an employee representative to discuss health issues related to worker exposure to paper dust, exhaust, and other concerns. Mail sorting machinery and HVAC systems were inspected, and records from the occupational safety and health program and from human resources were reviewed. Investigators performed quantitative area air sampling to determine inhalable dust concentrations, particle size distributions, and mite antigen concentrations. Of approximately 1093 manual clerks, small parcel and bundle sorters, flat sorting machine (FSM) clerks, optical character reader/bar code sorter (OCR/BCS) clerks, and mailhandlers, eight workers chose to participate in worker interviews with a NIOSH nurse and complete a questionnaire. The questionnaire was designed to elicit information about work history, and current upper and lower respiratory symptoms, systemic symptoms, work-relatedness of symptoms, smoking history, and past illnesses. A total of 21 area airborne particle size-selective samples and 30 area airborne inhalable particulate samples were collected and analyzed to characterize dust concentrations and particle size distributions. Six area airborne particulate samples were collected and analyzed for mite antigen. The exposure limit recommended by the American Conference of Governmental Industrial Hygienists (ACGIH) for inhalable particulates not otherwise classified (PNOC) was not exceeded. Engineering controls observed at the loading dock were considered effective in addressing the issue of exposure to vehicle exhaust. No oxygen-depleting conditions were observed at the plant, and symptoms of oxygen depletion were not evident. Overall, the HVAC systems were in good mechanical condition. In terms of assessing ventilation, there are no minimum outdoor air flow guidelines specifically for the light industrial environment.