Document N2agaanEGy9wrY6dGxydj09aQ

l~- 416 GEORGE D. CLAYTON 2. One zinc plant equipped with reduction furnaces, retort drying.'qji other operations compatible with zinc plants. fv 3. One sulfuric acid plant. -1 Other heavy industries in the nearby area, which .interested the^i'i tors, included: two steel companies and one by-product plant in MGrj steel and by-product plant in Clairton; a glass company in Charleroi; and company and a railroad in Elrama. y- . '] A study of the plant processes and analyses of the raw materia those industries led the investigators to analyze the atmosphere for theS constituents: ,J Total particulate matter Lead Cadmium Zinc Iron Chloride Fluoride Acid gases Hydrogen Arsine Arsenic Sulfur dioxide Total sulfur Carbon dioxide Carbon monoxid' Oxygen Oxides of nitro Stibine Manganese *! Iron caibonyl 1 The investigators concluded that: It seems reasonable to state that while no single substance was, rcspon* :lj[i October, 1948, episode, the syndrome could have been produced by a combination?!^ tion of the action of two or more of the contaminants. Sulfur dioxide and its^oxid] ucts, together with particulate matter, are considered significant contaminants?-!!^ significance of the other irritants as important adjuvants to the bioloyeaTefeetati finaHy-estimatEd"oirthB"bBsiST5f presehf'khowledgel ' - Information available on the toxicological effects of mixed irritant gasel<is<fn data on possible enhanced action due to adsorption of gases on particulate JitiS!tt1fi$ Further, available toxicological information pertains mainly to adults in relatively**! Hence, the lack of fundamental data on the physiologic effects of a mixtur|^o'ra particulate ^matter, over a period of time, is a severe handicap in evaluatih^dffl atmospheric pollutants on persons of all ages and in various stages of healtibv^r** Although sufficient data were not available to determine the eXStjm agent, sufficient environmental data were available to make tetfcfofmh tions which, if fulfilled, would prevent a recurrence of the disaster. Li jPozo Rica. The third much-publicized incident occurred . inf ill Mexico,4 on November 24, 1950, with a record of 22 persons^deadlSfe ''KbsprEalizST- ",11 'th6 history of the incident shows that the suj^ur|^^ (Girbotol unit) began.,operation on November 21, 1950. A fewls.dAj|I unit was in operation trouble developed, when the amine, spjutionpgj _Pfldly^pluggingLth'eigaSih`ePtd^he-pilot^ligKts^ortfio^nre^H;c!^B^^ appeared normal under the reduced rate of flow. jgi On November 24, 1950, at approximately 2:00 a.m., effortsL^eS `L. C. McCabe and G. D. Clayton, Air pollution by hydrogen sulfidefeimp Mexico, Arch. Ind. Hyg. and Occupational Medicine, 6, 199-213 (1952). n jkfi AIR POLLUTION 417 ggpffigSflMb. ate of flow of gas to the plant's rated capacity of 60 billion cubic ||H||p9ie desired rate of flow was reached at approximately 2:30 a.m. rvrrwn&tely, 4:00 a.m. difficulty was encountered, and the gas flow began E** Jug)v,the unit, with the probable result that unburned hydrogen sulfide Sthe atmosphere. g$uailable meteorological data indicate a pronounced low-altitude tem^inversion, a high concentration of haze and nuclei, and a very slight upfjiifat prevailing. w^^erniological study indicated that the time of onset of the incident inmh.^L'oO a.m., and the acute phase was ended about 5:10 a.m. The victims .SffihaVd-rini.a geographical area in direct proximity to the effluent stack of jjivl^foLupt; During this short period, the acute exposure to the atmospheric ^^^^^paediithe death of 22 people and the hospitalization of 320. oif-et, the symptoms and signs, as well as the pathological findings, are 'gntwlh hydrogen sulfide poisoning, and there were no findings that con- cilOT-his diagnosis. Therefore, it is to be concluded that the hydrogen hat^caused this morbidity and mortality came from the effluent stack of l^raiunit. ^^feEiuring the period December 5-8, 1952, the fourth and worst air- jjjdNas|er occurred. When these deaths were being recorded, the London erjeiicdd: periods of smog, culminating in one of much intensity. The onset J|||||pied by meteorological factors of low temperature inversion and ^?upl.e|^absence-of_wjnd-,oiL^LJn!m!ffient.,Jo_radip or balloon-sonde Bfflysde;.withm tvh--e f'o~go b-e-lt-. A-s-cents at Carding--ton, 50 mifes north of Magjjva^ijrasibility did not fall below 1,000 yards during tlie period, show ||ujn|iny.er8ion from groimd level up to heights between 500 and 1,000 aircraft landing at London Airport after, the fog had cleared 8S@ti&6fllBe)the height of the inversion at 200 to 300 feet, with a haze layer |jjM|ji|iieet. i;,,v jgM^^Kfirst air-pollution disaster where air sampling was conducted ^j^^P'nd after the episode. The data collected:1 showed the particulate :lJjainecL".*'by* -||m8 of stoatma1pl lwin-egoigw`htit-hperfilcteu*bricp* ampeetreranod*f arier-)p\ orratningg-e. d-ithefer--oti--dae.0ga.r3eo0en of to lmfeameter..oLair^with-.an-average of 0.50- forothe.-twGiyi'eek-period Iplihster.!: On the days when deaths were occurring, the values tygj^dmmn of 4.46 mg. per cubic meter of air, a ninefold increase fi^pwsrage- . ,*>.<>. .=. (dioxide ranged from. 0.09 to 0.33 p.p.m. with an average of 0,15, for pod precedteg^he-disasterr'During-the--period-wKen;H3eaths-wer-e- ^J^^^alues increased to a maximum of 1.33 p.p.m., which was also ^l,Efe|!ase over the average of the preceding days. jnl&eeks ending December 13 and December 20, 1952, at least 3,000., ^gred than would be expected. Although the increase was(present