Document eQN6j4GqX2xzxpLyrepv389m

the bay areas and "0.12 to 1.18 fibers/cc in the Relining Department. In contrast, general area samples collected in 1977 at this facility indicated the following range of concentrations; Office - 096 to 1.68 fibers/cc; Garage (east side) - 0.26 to 1.72 fibers/cc; Garage (west side) - 0.24 to 1.71 fibers/cc. It is readily noted that these con centrations are higher than those of the general area sample results found at the auto brake service shops. The areas of highest exposure concentrations at the tmck brake service shop appear to be in the vicinity of the rivet, punch, And pad grinding operations. The rivet operator's TWA concentrations were 3.41 fibers/cc (1976) and 4.47 fibers/cc (1977), while that of the punch operator was 0.68 fiber/cc (1976) and 7.52 fiber/cc (1977). Metal Analyses Trace metal analyses were performed on airborne samples collected during the 1977 survey at Facility E (Table 8) and at Facility G (Table 9). Samples were analyzed for trace amounts of the following metals: lead, iron, zinc,'chromium, nickel, cobalt, copper, manganese, and aluminum. As noted in Tables 8 and 9 most of the metals were either non-detectable or found in trace amounts. Fiber Characterization Samples selected for transmission electron microscopy (TEM) were sized by length and diameter and fiber concentrations (fibers/cc) determined for total fibers and fibers > 5 ym in length. These concentrations were 9- -