Document G90Dn7GJYb7bwp0NZOpZZJZ7

74 CHAPTER 6 I960 Guide AUitv^ <H*rv"d Uni'^ * Aske'w P Bmb, and W. B. Shelley: 1T upper limits of environmental heat and humidity tolerated m? worMnS environments (The Journal g,Industrial Hygiene and Toxicology, Vol. 27, March 1945, p. asBV>CR^".?i*S' M B.) PerfcAer, and Carl Cutberiet: ""Vi. RasaaHca Rd-obt No. U8a--Local coolin* of workers in hot industry (ASHVE Tusnbachoms, VoL 47, 1941, p 403) "FwJ- od C. P. Ya*loo: ASHVE BeuLbch Bn- fobv no. 673--Determination of the comfort zone (ASHVE TH^aAcnM^Vol. 29, 1923, p. 361). F. CHoughten id CP Xf^ou:i^HVK^fs^CH Beron No. 691--Cooling effect on human beings produced by various air velocities (ASHVE mMuillEer*.<AaSSHSV^ETMRes3e0a1rIc9h24aReppos1t93N>o-c. 7-1p7--Effective"tdemWDeraatere wi^ ciotemgaSHVE Transactions, Vol. 31,1925, pllS)' "d W* E* Mmer- A&VE rT0rr^% w'Hec1t1av"e-'(teAmSpHeVraEturTeWfoarapcenrosnonss, HOI V r92^ P ii5) G P ,ylo". w H. Carrier, Dr. E. V S.0^ten* j"d 7 KWalker: How to n the ef- "0!"^^ Ch"" <ASHVE Ts"s' E .Ci,"teilN,u: Adams. C. K. Bellamy, G. D. Fife, *. P. Heckel, Dr. W. J. McConnell, F C McIntosh A R NTnvSJ^S- `aic- T*8ker; ASHVE ts^wzTwl.`Ur "p,iiti0^ (ASHVE rronf V,,lIS;P?^, ^^na for comfort (ASHVE W J)' S' Horten, Cart Gutberlet, B. W N^noj^Sli^v 3; Tomiamon: ASHVE Bkmch Repost ," ,,,,,.0*~S"3ck apenenoes of 375 workers after entering and SleaviingrcWooled aTnd-<u&r cio7nld> it.i?on.eGd hocfkficmeasn(;ATSHIVoE,,uyT^ranb"aEc. Telaer, R. W. Keeton, F. K. Hick, and M. K. Fahnestock 'Phvs- lologic adjustments of human beings to sudden chamrp in in gronment (ASHVE Transactions, Vol. 53, 1947, p. 327) N Ghckmao Tohru Inooye, B. W. Keeton, Ml), I. W. Cal!m,` MJ-'-' flick, MD. and M. K. Fahnestock* ASHVF R*. patients to suddra changes in environment (AbHVE Transactions, Vol. 55,1949, p. 27). F. K. Hick, MD, Tohni Inouye R W. Keeton, MD, N. Clickman, and M K Fahnestock: ASHVE Research Report No. 1447--Physiological adjustments of clothed human beings to sudden change ^ en_ hot * Utcr comfortable conditions 1952; P-189)- Tohni Inouye, . K. Hick, MD., R. W, Keeton, MJD, J. Losch, and N Ghcfanan: ASHVtf Research Repost No. 1463--A comparison of pbyaologmal adjustments of clothed women and men to sudden changes m environment (ASHVE Transactions, Vol. 59, WS3. p. 35). Tohru Inouye, F. K. Hick, MD, R. W. Keeton, KAK B?n"teia* MD.: ASHVE Research RsroS wo. 1508--Physiological responses to sudden changes in atmosphenc environment--Studies of normal subjects, obese, hypermy7<3!X "d 3b1y^oUiyroid patienta (ASHVE TaaKBAorioiis, Vhl. G,r.iS-B- G"*P. C. Tasker, and Cart Gutberlet. ASHVE Research Report No. 1055--Coolin* re quirements for summer comfort air conditioning (ASHVE Transactions, Vol. 43, 1937, p. 145). nJjii?* Konzo> M. K. Fahnestock, and E. L. nW ` A?I5B Rskab,ch Report No. 1012-Study of sum- the research residence for the summer of 1834 awv??- Mcnr- VLf 1935, p. 207). C. P. Yaglou: ASHVE Research Report.No. 1319-A method of imprSSg S3 1SroV|vJfn^k"e "d (ASHVE TaANSAcnoNS, Vol. w`nM7'Inouye, F. K. Hick, MD, S. E. Telaer, ujSlpffl?' Etonr M-D.: ASHVE Research Report No. ?'S^7r^ct re^uy.e humidity on heat loss of men exposed Vol 59 ^^ ^ % "d 72 F (ASHVE TransSS, 'p* f29)* M. K. Fahnestock and J. E. Werden: En- W5^th43"d PK,Ple En*. RKeS;^!?teMWvK-^f*g",'1<ind W.E. Miller: ASHVE ^hihf^a,.^SP,n'jNo'^P_VEffecUve temperature for persons ^L 3J,19KTi`13l5r*`n8 " m *" (ASHVE TBansacnonB, ,,'A- P, ^*P. A C. Burton, end H. C. Oasett: A practical WStem of unite for the description of the heat erchange of man with his environment (Science, Vol. 94,1941, p. 428). C. P. Yaglou: Thermal insulation of dothin* (ASHVE Transactions, Vol. 54,1948, p.291). ^ ffifHVP Pbiiip Drinker,-and K. D. Blackfan: AppUadltlomng premature nurjeries in hospiSds (ASHVE Transactions, VoL 36, 1930, p. 383). CHAPTER 7 AIR CONTAMINANTS Clossificcifion of Air Contaminants; Sizes of Airborne Partides; Air Pollution by Smoke, Ash, ond Cinder*,* Smoke Abatement and Air Pollution Control; Odor Nuisance, Odors and Odor Control, Odor Removal; Industrial Air Contaminants, Flammable Gases and Vapors; Combustible Oust*; Atmospheric Pollen,} Airborne Bacteria; Radioactive Air Contaminants HE normal constituents of the earth's atmosphere are Fumes are solid particles commonly formed by the conden Toxygen, nitrogen, carbon dioxide, water vapor, argon, sation of vapors from normally solid materials such as molten small or negligible amounts of other inert gases, hydrogen,metals. Metallic fumes generally occur as the oxides in air variable traces of ozone, and small quantities of microscopic because of the highly reactive nature of finely divided matter. and submicroscopic solid matter, sometimes called permanent Fumes may also be formed by sublimation, distillation, cal atmospheric impurities. From the viewpoint of the air-con cination, or chemical reaction, whenever such processes cre ditioning engineer, all other airborne substances may be ate airborne particles predominantly below the I micron size. termed contaminants. This term is applied preferably, how Fumes permitted to age tend to flocculate into clumps or ag ever, to undesirable or chance impurities, since the occasion gregates of larger size, thereby facilitating removal from air. may arise for adding to the air controlled amounts of solid or. Smokes are the extremely small solid particles produced gaseous diluents for the prevention of explosions; germicidal by incomplete combustion of organic substances such as' to vapors or mists (aerosols) for bacteria control; masking bacco, wood, coal, oil, tar, and other carbonaceous materials. substances for odor control; or a substitute for one of the The term smoke is commonly applied to the mixture of solid, normal gases, as, for example, when helium is used to replace liquid, and gaseous products of combustion, although the nitrogen in atmospheres for compressed air workers or divers. technical literature prefers to distinguish between such com Since control of the chemical quality of air is one of the ponents as soot or carbon particles, fly-ash, cinders, tarry functions of complete air conditioning, some Knowledge of the matter, unburned gases, and gaseous combustion products. composition, concentration, and properties of air contami The finest particulate constituents are much less than 1 mi nants under various circumstances is essential to the air con cron in size, often in the range of 0.1 to 0.3 micron. ditioning engineer. Air contaminants arise from the normal processes of. wear, Mists and Fogs erosion, windstorm, sea-spray evaporation, thermal disinte gration, earthquake, volcanic eruption, combustion, manu facturing, transportation, agriculture, and the biochemical Or biological processes of life. They are classified at various times as organic and inorganic, visible or invisible, microscopic or macroscopic, particulate or gaseous, toxic or harmless, bene ficial or destructive. The following classification is based chiefly upon the origin or method of formation of air con taminants. Mists are very small airborne droplets of materials that are ordinarily liquid at normal temperatures and pressures. They may be formed by atomizing, spraying, splashing, mixing, violent chemical reaction, electrolytic evolution of gas from a liquid, or escape of a dissolved gas upon release of pressure. Very small droplets expelled or atomized into the air by sneezing constitute mists containing micro-organisms that become air contaminants. Fogs are limited by some classifications to airborne drop CLASSIFICATION OF AIR CONTAMINANTS Air contaminants may be classified in the following groups: (1) dust, fumes, and smokes which are solid particulate con taminants, (2) mists and fogs which are liquid particulate contaminants, and (3) vapors and gases which are nonpar ticulate contaminants. lets formed by condensation from the vapor state. This arbi trary distinction between mist and fog is of minor impor tance, as both terms are used to indicate the particulate state of airborne liquids (occasionally termed aerosols). Fog nos-. zles are so named because of their ability to produce extra fine droplets as compared to the mist from ordinary spray devices. The highly volatile nature of some liquids quickly Dust, Fumes, ond Smokes reduces their airborne droplets from the mist to the fog ' range, and eventually to the vapor phase until the air be-y^ Dusts are solid particles projected into the air by natural forces, such as wind, volcanic eruption, or earthquake, and by mechanical processes, such as crushing, grinding, milling, drilling, demolition, shovelling, conveying, screening, bagging, comes saturated with that liquid. Many droplets in fogs or clouds are microscopic and submicroscopic in size, and may be conceived as the transition state between the larger mists and the vapors. and sweeping. Some of these forces produce dust from larger masses,-while others simply disperse materials that are al Vapors and Gases ready pulverized. Generally, particles are not called dust un Vapors and Gases are nonparticulate air contaminants. less they are smaller than about 100 microns. Dusts may be of Vapors are the gaseous phase of substances that are either mineral type, such as rock, ore, metal, sand; vegetable, such liquid or solid in their commonly known state, examples be as grain, flour, wood, cotton, pollen; or animal, such as wool, ing gasoline, kerosine, benzene, carbon tetrachloride, mercury, hair, silk, feathers, leather. iodine, camphor. Vapors may be changed to the solid or 75