Document dQamyzVBJxopOb4bRdN7QK980

Calculation The total weight of brake linings in use is 10Q'02o6oQ X= 200,000 Tons. The quantity worn off these linings per year follows from the assumptions made in c. as 200,000 x | x = 200^000 Tons/yr> This wear dust contains 1% asbestos, hence emission is 200, QQP x _L_ = 2000 Tons/ 6 X 100 6 /y Allowing for the fact that 20% is not emitted, the total emission is thus 2000 80 6 x 100 pp = 270 Tons/yr. Effect on the Atmosphere There are no facts relating directly to asbestos on which one may judge.the effect of these emissions oh urban air. However, there has been a considerable amount of study done on the diffusion of other materials from automobiles, particularly lead and carbon monoxide. At a recent ACS Symposium in Minneapolis evidence was presented which placed the level for 33 lead emission at 0.01 (.ig/m in Thule, Alaska and 2.5 jig/m in New York City. Next to busy highways a level in excess, of 3 50 |ig/m may well be possible. In the light of this data the 3 value of 2 ;.g/m for average urban air conditions, suggested 4 by GM , seems eminently reasonable. Considering that 1.25 x 10^ tons of lead are emitted in total from automobiles then the following factor is used. Avg. Cone, asbestos in city air from automobiles Quantity of 3 2 iiq/m city air asbestos emitted x 1.25 x 10"* tons Pb from cars Applying this figure to the present case and assuming that 200 tons are emitted in city areas, then we get that: IIT RESEARCH INSTITUTE 68