A longitudinal self-report diary study of SBS cases and controls identified from buildingwide surveys of 4 office buildings is described. Self-report diaries were distributed to a total of 214 workers in the 4 buildings, and complete returns were obtained for 123 workers (57% return rate). Climate conditions (CO, CO2, formaldehyde, respirable dust mass (PM3.5) and particulate counts (0.3 μm, 0.5 μm, 1 μm, 5 μm), settled dust, air temperature, %RH, illuminance) were measured at each workstation. Ergonomic factors (observed work posture, office type, desk paper coverage, desk clutter, computer, mouse, keyboard tray, age of chair, chair arms, and plants, were measured at each workstation. Results showed no differences in prevailing climate conditions measured at case/control workstations. However, case reports of symptoms and environment conditions generally were worse than those for controls, and these reports showed periodicity, peaking late each day. The differences between reports by cases and controls generally remained consistent throughout the duration of the study.
Effects of proper drilling control to reduce respirable dust during roof bolting operations
