Abstract
The monitoring of the asbestos concentration in piled particulate matter on roads generated from the brake friction materials of automobiles has been studied. The concentration of dust produced by brake friction materials in automobiles was determined based on the concentration of phenolic resin in piled particulate matter; further, the concentration of asbestos was estimated from the concentration of the brake friction materials. Piled particulate matter on roads in Tokyo area was analyzed, and the concentration of asbestos released from brake friction materials during traffic was estimated. The asbestos concentrations in the dust of brake friction materials were 0.36-2.1, 0.20-3.0 and 1.5-3.1mg/g on national highway No. 246 and loop lines No. 7 and No. 8, respectively. The concentration of asbestos dust having a long-fiber shape was estimated to be several tens ppm or less.
