Document qeGygw8X0ZRre9yapV82oXJM

Industrial Hygiene Digest May, j 3q'J atmospheric contamination below the maximum allowable, provided adequate uncontaminated make-up air is supplied. For plants utilising solvents with more than 3f. benzene content, local exhaust ventilation should be relied upon for tontr.ol of the .solvent vapors. Ventilation specifications have been included for .the control of solvent vapors resulting from the churning, saturating, and coating operations, -- Public Health Eng. Abets. COMMUNITY AIH HYGIENE 486 A Study of Air Pollution by Analysis of Particulate Material Collected from Air filtration Plants. II. Determination of Pplveyclic Aromatic Hydrocarbons in Total Air Solids. A- J. Lindsay and J. R. StanLixy. Intern. J. Air and Water Poll, b, 387-390 (Sept.-Oct. 1962). The polycyclic aromatic hydrocarbons, pyrene, fluoranthene, 1,2-benzpyrene, 3,4- benzpyrene, porylene, l, 2-benzperylene, anthanthrene have been determined in air solids col* looted at 3-week intervals throughput the year from an air filtration plant. The methods employ ed were extraction with cyclohexane followed by alumina column chromatography and ultraviolet spectrophotometry. The amounts varied in the well-known yearly cycle for combustion pollution. The yearly average figures expressed as percentage of the total air solids were 0. 012 for the 7 hydrocarbons and 0. 0014 for 3.4-benzpyrene and these were contained in soluble organic matter amounting to 4 5%. The. nature of this material is as yet unknown. In the large amount of almost entirely uhinvestigatcd material there may be quantities of other compounds with biologi cal activities. -- APCA Abets. 487 Problem* in Smoke Control Areas. P. D. Coates. Smokeless Air (London) 32, 260-263 (1962). One of the problems In smoke control areas is that the majority of spontaneous objec tions from individual house-holders who feel that other local forme of air pollution, such ae railway .smoke, diesel smoke, or industrial emissions should be taken care of before the domestic chimney. The Beaver Committee emphasized the importance of the domestic chimney ae a source of smoke. Use of coke has been recommended in black areas because the present production of premium fuels is not sufficient to meet the demand for open fire fuel. Education oi the public is needed to show (hat coke can given satisfactory results and there are ho supply difficulties. Thete are minor problems and difficulties In setting up smoke control areas. -- APCA Absts. 488 A New Wet Process for Precipitating Fine Dust. J. Fallingsr. Staub 22/ 270-273 (July 1, 1962). German. Dust-laden gas is drawn into a venturi; a water spray is directed axially against the contracting inlet of the venturi so that the water droplets strike the curved walls and bounce off into the throat. The velocity of the gas and dust particles exceeds that of the water droplets in the contracting inlet but is less in the slowly expanding outlet tube. Graphs are given for pres sure 'loss as a function of water flow but data on dust removal as a function of particle size are lacking. The system is in use in steel works using oxygen-lancing. -- Bull. Hyg. 489 Diesel Smoke and Its Causes. J, M. Dlckaon-Slmpton. Smokeless Air (London) 32, ,303-308 (1962). Black smoke occurs when carbon particles are suspended lathe exhaust from a diesel engine, and carbon results when there has been a shortage of oxygen in the combustion process. Exhaust usually classed as just-visible contains only 4 mg. of carbon per cubic foot oi gas. A < 26. 03121232