Document rBBX4g23gp3mdzaKq4g7xmENG

TABLE 7 Analyses of Particulates in Atmospheres of Nonurban Areas (Average values in ag./m1) Vicinity of Acetone-soluble Mn Pb Sn Fe V Cu Be Ti As F- S04-- NO,* Tolal load Boonsboro 8.7 0.00 0.1 <0.01 3.7 0.003 Nil 0.0001 0.26 0.01 -- 0.3 68 Salt Lake City 6.2 0.04 0.1 <0.01 4.1 Nil 0.28 <0.0001 Nil 0.03 -- <0.01 -- 55 Atlanta 9.3 0.11 0.9 <0.01 2.7 0.004 0.01 0.0002 0.13 0.01 Nil 0.5 -- 71 Cincinnati 9.0 0.07 0.4 0.01 2.4 <0.001 0.19 0.0001 0.01 <0.01 0.26 . 1.9 6.7 45 TABLE 8 Relationship between Averages of Total Particulates and Organic Fractioriv. Large cities Los Angeles Philadelphia Detroit Chicago New York Intermediate cities Cincinnati Kansas City Portland Atlanta Houston San Francisco M'Iinneapolis.. Washington "Atypical" cities Anchorage Charleston --FoVPWbrtb--^----Nonurban areas Boonsboro, Md; Salt Lake City Atlanta Cincinnati Portland Average total load (Mg./m.) 265 188 344 280 244 176 146 143 137 129 104 120 130 308 288 -MO- 68 55 71 45 86 432 Average acetone-solubles (ag./m.*) Per pi aceionA.C. 57.3 30.0 50.9 45.8 37.7 31.4 18.4 32.1 24.2 18.5 .19_4_ 15.8 27.3 21.4 25.4 -T471- 8.7 6.2 9.3 9.0 12.6 AIR POLLUTION 433 a. air-cleaning devices rtK^g'l^effective and positive method of controlling air pollutants is at the proper air-cleaning devices. This method of control is adequately ? ,4"iii'CAhl__a_p_ TteVr IX . s-'i B. DILUTION or dispersion of the pollutants prior to reaching the ground * y$$$jfcStaokB has been the subject of extensive study for many, years. developed a theory on dispersion by assigning an expression '^'^l^yir.ogriate dimensional form to the correlation coefficient of Sir Geoffrey TC^STaJigjical theory of turbulence. Shortly thereafter Bosanquet and in the Faraday Society Reports a theoretical equation .based *u??im,i:[oiis studies of smoke from stacks of different heights, which in subiollows: The peak concentration of an effluent reaching the . ground ^ir.ck;occurs about 10 stack lengths from the base; and varies inversely -i^JS^ULi-L'Cjf.of- the stack height. This means that the ground concentration from i^PiJtSstack would be approximately 17 times that of a 600-foot stack. After t'liq. concentration falls off until after some 50 stack lengths it varies iiniw-ite square of the distance from the source. Kfei- ni miilCirmperature of the gases being emitted also has considerable influence ,iqu|d.-concentrations. The investigation of Hill, Thomas, and Abersold87 SIS?SfB?$arl.y) ,the effect of stack gas temperature on ground concentrations, n^ju.nyids.of low wind speed, the effluent rising from a stack continues to "li^idScncounters air of equal density. Then it disperses laterally in all ;^lie. height that the effluent will reach will depend on its temperature SiliaWlBced out of the stack at great velocity. It is estimated that each degree rise in stack temperature is the equivalent of 21/2 feet of added " mrfiV^has pointed out that there is a great advantage, in giving the.plumes KsMuossible cross section, since this will minimize/losses of their buoyancy ^injounding air and so raise the height to which they will eventually rise. . o_b!jec.1t1iv..e. s-1h___o__uuld 1b__e_ 1,1_t__h__e__r__etfo___r_e_ x, -to--gXeXtI_t_h___e__m__ :_ax~s/h1iUg.h into the -Vibftabjg.mean8 of a very few tall, wide chimneys, and-a .certaineamount .osiitfi, ~.......... ............... ............................ IC?/Buftbn, A theory of eddy diffusion in the atmosphere, Proc. Roy. Soc. (.London). .m . S^mue.t ahd J. L. Pearson, The spread of smoke and gases, from chimneys, - --------------------------- d-fog--a-generai-di6ous3i&nT-7/rarig^gora3di/-iSon^32._ 'IfUijiljl, S. Thomas, and J. H. Abersold, Effectiveness of high stacksin overcoming oncentrations of gases at ground level, Ind. Hyg. Foundation Amor., Proc. of tifietiing, November, 1944. * 'Si'fP'r Plumes from tall chimneys, Weather, 10, 106-109 (1955). r-'.