Document nk83rdKKn0647y4N7mjNVJ71m

\uj) Lead In The Atmosphere In Association with Certain Industrial^Operations. /Operations of ^interest, located in the San Francisco and Los Angeles \antiknock compound containing tetramethyllead. areas, incXud`ed'rt'Se'"blending of gasoline with^the filling of tank trucks with such gasoline at refinery loading racks, the filling of barrels with gasoline, the testing of the gasoline by various methods (distillations etc) in refinery laboratories, and the dispensing of the gasoline at filling stations. The environmental conditions associated with these operations, with respect to the concentration of lead in the atmosphere to which workmen might be exposed, are being investigated systematically in a program of sampling and analysis. - r~ , v > I:.." y /C*' Th^rg~trej-ng--two--, one in each area, -'<r two sets of'. operations a'*=e--bein@--subjected-4o investigation. In addition, twenty-one gasoline service stations were included, ten in the San Francisco area,and eleven in the Los Angeles area. These stations were selected on the basis of the large quantities of gasoline dispeneed and their geographic distribution within the two cities. In order to ctotfecjjtniBe >the impact, if any, of the use of . f: v-.'y,!/ </< Y,y /?;. . / t-*l/ tetramethylledd upon the/gener^L-nv4-romnen&--^nfl metropolitan areas, <**>' -<v i-t-a*---!-'.: jf : .p'u.jy' c. ^ S' . / V / .......... ... oteaerva=t4^3trs are^being made of the concentrations of particulate lead 2- - 5T* Sr\tA YUUIa / *$yuu selected -as be^agC^pepreseiita-tive of general conditions -of- the -approximate centers of the downtown commercial areas of each city. Procedure* The same sampling equipment and procedures for collecting the samples are being used in the environs of the two cities, all tests being .t K-- conducted by technical personnel of the two major suppliers of tetramethyllead> AM) .,, .hP V f, . ^'<*Z*is**4-*!**' V ' Vc.: <,,/cjt.,.c_ suppliers^jy^responsible for carrying out the sampling program i j -* ' in a \* ingle areatj S3 ^ I, *?.:; *<>>* */ .If L-- Us>Cr* 7*-=- ^ i C f" % < .4' ^ &css%P. {Jtu-f ~CX j Organic lead is being determined by means of ^ >,* < f. specially designed equipment furnished by one of the suppliers. In initial tests, four ct-V cubic feet of air -were drawn through the collecting equipment at the rate of 0.5 cubic <e$t per minute. However, as a result of an investigation of the chemical properties of vaporized tetramethyllead^it was found advisable to cju reduce the rate of sampling to 0.25 e^M^r'and" to use two iodine scrubbers in series. The lead retained in each scrubber is being determined directly . -- /- in the field, and the sum of the two values is being recorded astheT/organic lead H*ess% per cubic foot of air. The rate <f sampling at the service stations is the same as that used in the other test areas/except that the total volume of air sampled 3 is 8 cubic feet. Before air enters the iodine scrubbers, it passes through a millipore filter, which removes the particulate lead from i the air. The concentration^ of organic lead determined directly in the r j ` j- 'UC/ -XZi&Htif w?y to field, while the millipore filters are shipped to) Cincinnati for the analysis of their content of inorganic lead. The^^Sonc'entration! of tSe particulate lead compounds in the K'J, atmosphere wwi: Jgms commercial centers of Los Angeles and San Francisco are being determined by the analysis of material collected on glass-fiber filter webs p4e?ed- in Staplex high volume samplers. The material from about id[>t<s hum-i 2000 j^"63Tair is being removed from the air by each filter during each /f 24 hours of sampling. The filter webs are being shipped to Cincinnati for analysis. The following frequencies of sampling are being employed: Xv- - \------------------------------ 1. Blending plants and loading racks are visited every other week. 2. Other samples in refineries ^rom^labora;tories and barrel filling operations) are being collected as ll* (Xc Jl ','C opportunities present themselves in connection with fVwSet/ if ^operations. These samples are being analyzed only for their content of organic lead. K 000" 091 4 yXw i < 3. Each filling station is being visited^jtwo times per month. The&f; samples are analyzed for their content of both inorganic and organic lead compounds. SSojVjsMawidgy f- ;>J ,-i 4{ particulate material fronilthe general atmosphere are being collected every other day and are being analyzed for their content of inorganic lead, [ u-d-t r ' '/ '} > >* ... 'j ` . 2 ./Us/ezJ tJ ."V r ` nUviV-e'f '"'.'o " ''w.'-a/. ,ik.i mU-t- j The fi-Tvdingis--in.-this report, derive from &&& Jsbumse samples collected up to February 2, 1961 in San Francisco, and up to February 9, 1961 in Los Angeles. Tables 1 and 2 give the mean concentrations and the frequencies of occurrence of certain ranges of concentration of lead in the air at the various locations in the refineries of the two areas. In Tables 3, 4 and 5 are summarized the results of the analysis of samples collected at the filling stations in San Francisco, Los Angeles and Bakersfield. The levels of concentration of lead in the atmosphere in commercial centers in the two cities are compared in Table 6. --BreeflHKJiTr -- --------T-- , -Ia-Lhe.-jLo.ilowing^dlffcussA^a^-^nd all of the tables except Table 6, the concentration of lead is expressed in micrograms of lead per KE* 0007532 5 -j & -; &*&#*'*<**4j ' ! ^ *'-; cubic foot of air. he tln-ershol-d limi.iT:of k*J &- ~%k- v>t"ir*C,J .>V/iA*S*-r< o/5 '^00-iniorogT^nns-nTf^e^^cubic meter of air, ''' t. iad.ustrial_prac-ta.-&e^ it is necessary to multiply .ibi-s~-vaiue by 35.3j the number of cubic feet in a cubic meter of air. As may be seen from the data in Tables 1 and 2, the highest ^ flevels of concentration of organic lead sesfs- present in the air when the i,L 'Mt-rc hi. domes of the tank carsjlBBiF'Tirst opened for connection to the lines leading r_ - to the-weigh*tank. ;"A much higher average level of concentration at this location was reached in San Francisco than in the same location in the Los Angeles area. i, The concentrations fluctuatefconsiderably, depending upon the /' ____ ' condition of the valve connections(and on hcsfcssoon, air sampling is started. /x SH;_.is-~b-Meved--thA$ the higher average concentration of lead in the air at the dome of tank cars in the blending area of the San Francisco refinery .. ; X .-8$2* due to the fact that wiy sampling was.c-?s'fca'r'tred as the dome was being opened ,f 't2 ' -vr ; ' and ^connections were being made , t-o~fehTMweigh. In Los Angeles s j .... * 0*5 , .0<v* +* * sampling was started tonly after connections to the`weigh-tank had been made. The two sets of concentration are representative, therefore, of two different i } _ ,,. - .* m.r.u.-'- . periods of}'exposure at the dome of the car. The peak, concentration of 35 micrograms per cubic foot, equivalent to 1235.5 micrograms per cubic meter of KH 000 7093 CO CD CD 6 air, was obtained in association with a leak in the dome of the tank car containing the antiknock compound. The actual exposure of the operator under thes> }>'.#.:t<4-tS-..jfu.it.}---" circumstances is negligible, since he approved canister respirator Ma4u.Jj,i,uih.a.t-=H m&r- / r> h ,: .m ' /, C-a-i Other operations in the process of^b+ending^ do not^teftS^geaefaHji ..'. V t.i "- ` ^jb^-eotrt^minql'te the air within the building ; v-' ? f.t-'-J O'r- -:o wi-glwfcak-) O'r-dn--thO' .... , - v-. '--A ' -- - , ,->/.. .... outside air of the area immediately adjacent to thfe blending,a ivavsEthedtes^i, air outside of the blending building in the San Francisco area contained dead a^-dtrgirer"T'eV'el than that within the building at the weigh "tank j i.fc&e&fT''' The reason for this was not iinfltt?dirat^el-y apparent but it may have been due to the direction of air current,-together with the location of the tank car or the position of the vent, during the unloading operation. The levels of fch concentration of lead in the air at the loading racks were generally in good agreement in the two areas. Average concentrations on top of the trucks were 0.64 and 0.85 micrograms per cubic foot, respectively, at the San Francisco and Los Angeles sites. At the Los Angeles operations, the average concentration at ground level was slightly higher than that at the top of the truck. The reason for this is not -ejttxxniy-- 4- - 5!a> tctjaaj-. ' cia<j^But it is not necessarily remarkable. Trace quantities of lead were 7 found at ground level at the loading rack in the San Francisco area. /-C Sir "Imis'-tyeen sampled during the filling of barrels with ....................................../ ' ' ^i,,x - ! gasoline containing tetramethyllead on only three occasions.; Organic /> lead could not be detected in the air during any of these periods. Twenty samples collected in the chemical laboratory were also negative. A trace of organic lead was present in the air of the inspection laboratory ! ;HL> > . r the wharf (locally designated as the "long" wharf) in--chmon-dr:--* - Small quantities of lead are~heing found in the air at filling stations. In the San Francisco area, the total lead averaged 0.26 micrograms per cubic foot (9.2 microgram/M3). Of the total, lead, 43 peijcent^or 0.11 microgram per cubic foot (3.9 microgram/M3)^was inorganic, and 0.15 microgram per cubic foot (5.3 microgram/M3), or 57 per cent, was inorganic in nature. In the Los Angeles area the total lead in the air at the filling stations averaged 0.132 microgram per cubic foot (4.7 /5s.microgram, The inorganic lead constituted 64 per cent of the total lead present (0.085 mlcrogram/Jj equivalent to 3.0 micrograms per cubic meter of air. The organic lead averaged 36 per cent of the total, being 0.045 microgram per cubic foot, or 1.6 microgram per cubic meter.of air. '% At one station in Bakersfield, where 19 samples have been KE 0007393 8 ,,C< collected to date, the average total lai concentration ^was 0.28 microgram per cubic foot of air^, equivalent to 7.9 micrograms per cubic meter. Inorganic lead averaged 70 per cent of the total, or 5.5 microgram per cubic meter. The higher average concentration of organic lead in the air filling stations in San Francisco as compared to those in Los Angeles, is due tot difference^ '*"t! In Los Angeles,^air is being sampled near the fueling islands, but not in the immediate vicinity of the gasoline pumps. In San Francisco, the intake of the sampler wars. located at '-``M approximately the same level as the f=fcSE3233r opening the fuel tanks of ii'Jdu the carf^'and'"about twoTeet from the opening, -a \ . f) -in--th-e--ease^o-f j San Francisco A t-heref-oise,, as,* 7',+r * "ty 'fefe^ira?7tmft~eevTCT^ t i, t iTl; , the pxpogiirp -*-q ^k an airftTi^Trtr--M^lTt-~be--^ub^o<^od^;iX he remained, a.t_^S-UCh-,a.-jJoLnt-.dnr.i na -the. *fuiFa. <s u a Xx >;j /. if "20 ***- /v ! ............... l... ' " "'"r -- entAxe-.-pe'rLod'-'o..-f-ugling. ^ In Los-Angel p^r'-thp i Rye1 g = >;- t<x <? j- fi-'ifAjxf vj' <L^ufHntJ i.^Z: daJSJ ** *$ 4 take--inti3,,ia.CCount....athe-g--dtrties pel-formed by tne--atrtendant. '*%&--two-- f yCaj ;A~<. ~-J 'A '**- -j uV<*f ( ft.**-? *<$* *v* sets of data.* supplement each other in tlrTt*l,,(wtee--4j.r,p.'Brirrt: certain variable possibilities for exposure to vaporized tetramethyllead at service stations. s'TKr3^^ The average concentration of inorganic lead in the air KH* r\ r\ /- n n UUu < o 6 the V *3 fi ^ -i * / ^oaae^e*^ 9 >MW Los Angeles (5.3 raicrogram/M3) is approximately three times as great as that in the air of the oemmcrri-aJ-eeiTtttr (1.9 o microgram/M*3) ^"14 San Francisco. The average .Vr r . tie.- fr>]jj3.ri. .iHj ft Ccw.t 4,,- the present investigation ase.^,.i^f.eivala4rjpwte<att--<ompaCie<i with the averager 33 -vaiTRs of 5.2 microgram/M and 2.4 micrograms/M ) found in Los Angeles and San F.rancisco^respectively^ in 1954 by Chambers and associates (Chambers, L.A., Foter, M.J., and Cholak, J. A Comparison of Particulate Loadings in the Atmospheres of Certain American Cities). Proc. 3rd Natil. Air Poll. Syrap., Pasadena, Cal., April 18-20, 1955; 24-32). Additional information dealing with the impact of the increased use of motor fuels on community air pollution nay be gained by comparing the average concentration of Ot 5.3 microgram/M , as observed in the present investigation,-.with that of / 6.75 micrograms/M^, as found in August to November of 1954 in Los Angeles, KET (Cholak, J., Schafer, L.J., Yeager, D.W. and Kehoe, R.A., Chap. 8, "The CO Nature of the Suspended Matter, Report #9, An Aeroraetric Survey of the Los O Angeles Basin Aug.'- Nov., 1954, N.A. Renzetti, Editor, Air Pollution Foundation 1955). The Our2:^n't^l^ed-s-~o*f-<&n-3en-t^crtrions' are,>a-f interest ia-tha-t----/ S 'y I --is contrary to predictions based on sinapiie calculations from contemplated increases in the numbers of motor vehicle and in fuel consumption, which have 10 been given nationwide puclicity. The results of the current investigation while limited to a single central station in each city, appear lu demonstrate "-fch-e- axa-s^>-oa~ofUa~&rnrrsepends -to that obooi tfud Til XTflgTHlht'li,1'' f-1 if? " H- V. ^ ^ f **<-*:*+*> * & rttrtnr--FfrH-n--r--HrT-fT-rl in iwAnqjirai.ta..from / / ---/ m *? * .* **4***.. y ^ *e-***U*# M. Usl****-**- lf)rfG thrmif-hi - lff-& dZZ*+&u y , ffiTf 9 *^ that the t remL.jn~ t hvr,treftg?ciifairCTgrr^^J6MT'^^ r ?> Several factors were responsible forVfefeAs^J;reneh--inellmertillijas b...h...c......f.e...u..M....c...t.e.ti'gf _j;.. { " f f, ': j t" ;i > ft . *.*. '4K^ of expressways, the expansion of populations into the outlying area, and the opening up of the basin of the city, all of these tending to increase the dilution of contaminants. (Cholak, J., Schafer, J.L. and Sterling, T.D., The Lead Content of the Atmosphere. To be published in Journal of the Air Pollution Control Association.) 89\j u O < o CZ3 crr^