Determination of total suspended particulate matter and airborne fiber concentrations at three fibrous glass manufacturing facilities

Abstract

A total of 115 environmental and personal air samples were obtained in 3 fibrous glass manufacturing facilities to determine airborne concentrations of total suspended particulate matter (TSPM) and fibers within the plants. Fiber characteristics of length and diameter were evaluated by analyzing samples by phase contrast and electron microscopic techniques. TSPM concentrations ranged from 0.7 to 6.0 mg/m 3, <0.1 to 5.2 mg/m 3, and 0.2 to 6.8 mg/m 3, in plants A, B, and C, respectively. Airborne concentrations of fibers less than 5 μm length, determined by phase contrast microscopy of samples, ranged from none detected to 0.19 ± 0.05 fibers/cm 3 in Plant A; from 0.01 ± 0.01 to 1.34 ± 0.23 fibers/cm 3 in Plant B; and from none detected to 0.17 ± 0.06 fibers/cm 3 in Plant C. The concentrations of fibers greater than 5 μm length, also calculated from phase contrast microscopic analyses of samples from Plants A, B, and C, respectively, were: none detected to 0.15 ± 0.06 fibers/cm 3; none detected to 3.16 ± 0.36 fibers/cm 3; and none detected to 0.20 ± 0.06 fibers/cm 3. In only 10 of the 115 samples was it possible to detect, by electron microscopic techniques, the presence of fibers less than 1 μm in length. The 2 highest concentrations in the latter category were 1.16 ± 0.82 and 8.9 ± 2.6 fibers/cm 3. The total number of fibers in a filter sample and the sample weight, expressed as milligrams, were not clearly related in any single plant or when data from all plants were pooled. These results suggest that fiber content of the air cannot be reliably estimated from the weight of total suspended particulate matter in the air.