Document 0JQd4w91QXMkX6Eb6y0y499jb

r,13 m3 ;> t- j nn fJT3ic? totoJ. of broke 1 inincj^ in u*sg is '1.'~2000QQ'-X~ = 200,000 Tons. - The quantity worn off these linings per year follows from the assumptions made in c. 1 50' as 200,000 x ^ x 200,000 Tons/yr. This wear dust contains 1% asbestos, hence emission is aSVfifi * life - ^ns/yr. Allowing for the fact .that 20% is not emitted, the total emission is thus } 2000 6 80 100 " 1600 6 = 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 on urban air. However, there "has been a considerable ampunt 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 3 `3 lead emission at 0.01 pg/m in Thule, Alaska and 2.5 pg/m in New York City. Next to busy highways a level in excess of 50 jig/m may well be possible.' In the light of this data the value of 2 pg/m^ for average urban air conditions, suggested by GM , seems eminently reasonable. Considering that 1.25 x 10 tons of lead ?re emitted in total from automobiles then the following factor is used. Avg> Cone, asbestos in^city air from automobiles Quantity of 2-uq/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 iq city areas, then we get thfit: t, III HtSLARCH INSTITUTC 68 SPNY 006108