Document mBGnBX4oGDd8j9dRnzLw5YpDb

426 GEORGE Du,. \C4LuAaYiTLUO1NT :!$ from 0.001 to over 0.40 p.p.m., depending on the city and the time o4j| Detroit 96 per cent of 18,000 V2-hour readings were less than 0.15 p.p$|F per cent of these were 0.05 p.p.m. or less. Average monthly values ofQSQ: were recorded during the summer months of. June and July. During,)|tfj months the average values reached a high of 0.11 p.p.m. in December-s#1 Another gas found in the community atmosphere is hydrogen sulSe, at ordinary temperatures has a specific gravity of 1.19 referred to airy||p very low concentrations, a powerful characteristic odor. The sources may be a wide variety of industrial processes, including refineries, seffl stallations, oil fields, and, in slight amounts, auto exhaust. Air hygi|| interested in hydrogen sulfide because of its effects on health, its odorousfcn istics, and its economic effects. The toxic effects are well known. In l| air pollution, it was identified as the atmospheric contaminant thairlcifi people and hospitalized 320 in Poza Rica, Mexico.4 . t?||| The economic effects of hydrogen sulfide are best illustrated byyj| coloration of lead-pigmented paints, the reported incidents of whiclna| numerous to mention. It should be stated, however, that these reported1''1'*5' tions occurred during times when the excess liberations of hydrogen sulff classified as accidents. During normal periods the hydrogen sulfide ne|f such concentrations. Moreover, it does not damage plants in low confinj; Zimmerman28 states that when 29 plant species were fumigated witf|l 40 p.pm., little or no injury occurred. ...Data-on_th.e_cQncentrations.of-hydrogen-8ulfide4n-vaTiou8-citieB|^ In general, however, except for accidents, or in the direct patb-fr6f| source, the concentrations range from 0.000 to.0.020 p.p.m. 'ri% Hydrogen fluoride, with respect to air pollution, is one of the nioSiK; halogen compounds. Hydrogen fluoride is liberated into the atmos^" many sources; however, the biggest problems to date are in areas nea plants and phosphate-fertilizer plants. The petroleum industry, iiitK? of high-octane gasoline, uses considerable amounts of anhydrcjul| fluoride. Tables 3 and 4 show the data reported by Largent on cohb|nj|| fluoride and hydrogen fluoride.28 Fluorides are also used, and are a source of air pollution, in th|^laji .J'MniQg-QLmatala,4.pickling_o-metalsrelectroplating-operatipns^|tlm^; ware, steel, manufacturing, and cement plants. Although-' coab'viifif*24'1'*'^! content, its''biirfiing results in the emission of fluorides. * "P. W. Zimmerman, "Effects on Plants of Impurities^ Associated with-Ait^".1, -of. :<Ae^/^iS^(l6Afffiofrg^erni!e"w^^Pofiuttonf-Me'Graw-Hflh~N5W-y5fJfr'lt P. 112977. E. J. Largent, "Effects of Air-borne Fluorides on Livestock," Pro.c'i.eed'.u'tliglfip.oijltffflflll Technical Conference on Air Pollution. McGraw-Hill, New York, 1952, ** A. E. "CroBsley, Fluorine in coal: IV. The industrial significance of fluorinehii c steam-raising, gas-making and brewing, J. Soc. Chem. Ind. (London), 63, 34,X1011).'.%i AIR POLLUTION 427 TABLE 3 gggjptst _ Concentrations of Fluoride in the Atmosphere gfiiij'Or'in the vicinity of certain factories as reported by several investigators) ^Location JiF jaUig.plant (inside) SminUjm plant (inside) ^jpnum plant (outside) jjUpiifte plant (outside) Concentrations of F in air mg./m.* p.p;m, as HF 16-497 0.04-3.77 0.03-0.22 0.02-3 18-547 0.05-3.43* 0.04-0.24 0.01-4.3* Observer Roholm Agate Agate Largent Sm.amount reported in the gaseous form was 2.79 p.p.m. "Xamount reported in the gaseous form was 0.029 p.p.m. jTC-... TABLE 4 !||||ent of Samples of Air Collected on a Farm Adjacent to a Rock Phosphate Factory ^October Fluoride in air expressed as HF Gaseous component (p.p.m.) ` Total, including dust (p.p.m) 0.012 0.024 0.012 0.024 Nil --0,029....... N_il 0.012 4.3 0.024 0.056 Nil ............ .0.0.40 Nil 0.173 Sent-,concentration, hydrogen fluoride is toxic to humans; however, luiag^tgsplants and livestock from gaseous and particulate fluorides has JjilgSiOTpattention. The gladiolus is one of the most-sensitive plants,-being ^jh^itinospheres having values of only 1 or 2 partg,:p.f, fluorine tp.a billion JjrVa^r^Thjliypstock, fluorosis results in irregularly worn-teeth, a-stiff-legged p^pr{nuMljonal state, and a reduction in the output of milk. rt,",'l`','rr'Shd.*fliever,25 using filter paper as the collecting medium, reported an ' `wSiioiicentration in Detroit of 0.12 pg. per cubic meter of air; using ^mfe|pih6r'yalue-w,as40j87..pg...pen,cuhimmfiteiLftLai5:tiE3l&concluded u^len these values probably could be accounted for by the gaseous tn. Nitrogen dioxide and its polymer, nitrqg^tetrpjfide, are meiiin&un&.atmosphere.Sqroe, of the sources of this .^tsvaie-.the'manu> and the nitratibh ftf MlUliotie anti utlw'oiFipuirratiiaialsr Iture of celluloid and certain types of film. It is also liberated awAamd P. M. Giever, "Report on 1951 Environmental Findings." March, ^l|fitf3ection, International Joint Commission, Technical Advisory Board oil ll 1 i. i; j