Document GmJdK2qN1RaEqmNkXy84meQM7

LEAD INDUSTRIES ASSOCIATION. INC. It* MAOIION AVINUI HIW TOA*. N. V. 10017 IMMOM -- COM MC A i >j i * yobruary 8, 1$66 Tot All Hra6*r of tho UA-WJG Load Boalth aod 8afoty CcMolttoo Attacbo4 1 a copy cf a papar writton at our rcjJMt by Dr. Halay an} dl*ro4 to bo pubU*bo4 to tbo AMI Archly of terlronarotal E** 1 til. X vouli bo scat l=ter*st*4 to barlo* ycur r*ctlciOt coxwnto, aod criticImm of tbo wort. Tou vlU rcsMbtr that Hiiitl pooplo at our roeoot Ccoalttoo aaotlof unccrl lot*root to im'c ^ tM papor. Tory truly youra, varunt attacOaoot Coo 0. fovlor L*_ t o u>yfwT. r; fc. I r-. *- t K i S' V L. V: ;5 laboratory of uel*w Hr-llclo* od **4ltloo Biology Doportooct of *los*rlc ul ucU*r Qblvtrolty of CollforuU School of Mrdicln*, loo Aa*lM TM *rtlU vi ut>(>orV4 by Cctr*ct At{0k-1) 0121*12 botwooo iM AVuolo toorgy Cc m>L**1o o u i) U>* Iktwilty of CollforoU* **5*fc N 384.01 ! o ' ' ') i Recently a. gaoebaelat hM augg*ted that tba people of tha Ifcltad State a art being nibjacted to chroole load insult from Industrial aoureoa with tha raault that there ara functional ahtfta In higher nervous activity, (l) So alao stated that tha lead lavela In tha literature should ba aat soldo, nil dost not tail aanaa to tha tekiealoglst so It la taecmaanry to nawhnta tha past and current use of load la tha Uhltad States) tha aouroas of tha load entering tha bvman body) tha artahollan of load including load balaac* of tha body) tha nnnaar In which bona seeker* (such aa lead, streetUrn, ate.) are discriminated against by physiological mechanise* and last, but by no asaaa least, tha overall toxicology of load. C5Z3 OF LEU) ficanlnatlon of tha total uses of lead for tha periods of 1925 to 1929, 1952 to 1956 and tha yvare i960 to 196b Inclusive reveals only a alight Increase In cocjisptloa of lead In tha Obi ted State, (fig. 1). Such appllcatlooa aa manualtloo, bearing betels, solder, casting natal, weights and ballast and so forth have seen alight fluctuation and, la acot cases, actual decrease la total yearly usage of lead, figure 1 show* tha actual decrease la tha uaa of lead pigment* and building raterials, l.e., lead pipe. These changes have baaa brought about by tha development of substitutes such aa tltaolia plgmeota and copper or galvaolied aa veil aa plastic pipe*, by far tha greatest Increases la tha usee of lead have occurred In storage batteries and lead alkyl gaeollao anti-knock compounds. Thus, although large ameutrt* of lead ecotlnua to ba used, those applications, l.e., paints and plumbing, vhlcb vara Involved la Inadvertent toxicity In tha past have been alaost ellainated at tha present time. Decreases In tha use of lead*ccetalnlng Insecticide* have alao occurred aa a raault of tha introduction of tha chlorinated hydrocarbons and pfcoephat* Insecticides, lead InsectlcIdea utilised la 1933 vere 6000 abort tome, In 19<v* ware 25,957 abort tone and In 1959 so low that definite figures ware not given (2). Krn-Kxxx wo Aixna In view of tha Increase In usage of lead alkyls and their indictment aa a general causa of chroole lead Insult to tha general populatico (1) It la now necessary to axaailoa tha overall picture In sore detail, figure 1 show* tha Increase In lead alkyl usage for tha years 1JC5 to Yft* inclusive and this reflects tha increase In application of tha automobile aa tha principal Mans of treneportatlcn In the thltad Plate*. The prime qua*11 co la not tha Increased burntng of lead alkyl* by tha internal ecabustlcm angina with tha eubaaijuent release of lead compound* Into the air but th* type of compound* released, the area of r*lease, me particle ail* and solubility of these ecspounde and thatr overall availability to the public, ttlrscbler at al (3) bav* shown that tetraethyl lead daccatpoae* Into fb Cl-*r, fdffl^Cl*2IVCl'fr, f-Wti.Cl'rbCl-fr, ?XWkCl*fbCl*fr, JV**, IbO'PbCl **/> and In tha praeeoe* at phoeptata addltlva* jn>.(r>0^)2>n>Cl<fr. Bovaver, tf-, diatrlbutloo of th* various cexpounds depend* an both th* automobile and It* method of operation. I j ' ' -'^v^V-^X "Z s LIA11734;'- ,/ , V '- V; . Jf '.-=,. ' - v' ' ^ ' 2* 2- A nlrtur* composed of the amcclua-lead-halide complexes ppe*n predominantly under city driving conditions; whereas lb-Cl-Br appears at full-throttle accelerations. Moreover, the forcer complex** ere soet often famed la duel* exheuet syetea* which operate et lower temperature*. Comparison of clean vereue dirty exheuet systece lndlcetee that the forcer ealte 20 per cent of the lead burned while the letter emits up to 60 per cent. Severe eerrlce tende to clean the exhauet system. The range of particle else* eaitted range fran 0.01 microti to eeveral llllaetere In dlaaeter with thoee smaller then 1 micron, although more numerous, accounting for coly 5 per cent of the eaitted lead. City-type driving reeulta la the ealeelco of 27 per cent of the lead ae particles 5 alcruce and larger while acceleration lncreeeee this ealeeloo to 39 per cent. The particle else distribution and composition are Independent of the aaou&t of lead alkyl la the gasoline. The Inorganic ccapouade under discussion are relatively Insoluble and the aasoolis-lead-hallde to unstable that even the water la the exhaust ^ses can cause It to decompose to aore of the Inorganic lead compounds. It Is wtll known that the larger particles, above 5 ale rocs, have a tendency to settle rapidly and thoee that are Inhaled are trapped In the external narea. Particles la the lower site ranges are reaoved by two aerhenlanet ectrspeent la the brcocheolar mucous secretion as a result of centrifugal action produced when the air etreaa reaches the various brcocheolar bifurcations and direct precipitation oo the suctxis eecretlcos. In both case* ciliary actloo reaovea the parllclea froa the lungs mad allows then to be expectorated or swallowed and excreted via the gastro-lntestInal tract. The particles below 1 alcroo can reach the depths of the alveoli aad be absorbed directly or phagocytlred by the tissue tacrophagee. In either 6 event the total amount absorbed via the lungs Is only a snail proportion of the dally lead Intake ecapared to that absorbed froa food aad water. ?:ss 3 root LEAP OCWTTTfT la discussing autoochtle exhauet. It becomes quite apparent that the lead compound* released are rather Insoluble and thus can only be saell contributors to the lead content of the body. Only 0.03 eg of the dally lead intake cones via air-borne taterial; whereas food and llpild Intake contribute 0.3 ag to the total lead Intake of 0.33 * (*). Kefcoe (5) has shown that alaoet every food stuff and beverage eootalne sees lead ae a natural constituent of Its total mineral composition. This le not surprising because noet soils In this country contain between 15 and 20 ppm of lead which Is taken up by plants and transferred to anlaale eventually ending up In the hiaao food chain. Sinliar conditions apply to the water supply there yea the ring and leaching of rocks add lead to the water supply. Lead ae lb** le constantly released froa the earth's cruet ae a result of decay of the uranlua series of nuclides. Mayneord et al (6) have shown that this alpha saltier Is takso up by grasses and other plants Which are eaten as forage by animal* which In turn becaste part of the human food chain. IIlll (7) has shewn that the laad-210 which escapee Into the ataoephsre le returned to earth with rain and alls to the natural radio activity In the fond chain. Aurtcet and Otevart (9) found that the Mean residence tin of 1**4-210 In the atneaphre le about b ve*ks, sufficiently long enough for nixing to cocur but short compared to this nuclide'* half-life of 21.W years. Veter supplies also contain laad-210 as a result of rain or from leaching of the earth'* cruet by river watsr (9). Tbs total amount of l*ad-21Q is snail compared to stable lead but the** nuclide measurement* again point to the dally food and liquid cunsxsptlen a* the noet Important sources cf lead Intake by the biman. Ketoe ()) has pointed cut that, although **5at *3- lead coctaaioatlcn of food tad drIni can occur during harvesting tad processing, It la reaarkable that such coctaalnatloo la of auch t lew ordar ta to contribute cry llttla to the or*rail latd Intake. letd excretion follow* t definite pattern with facet containing 0-3 ag par day tad urlaa containing 0.03 ng par day* Thus the average individual la la latd balance tod not accuxulatlng excess latd to add to bit total body burden. Changing snvlrocaeotel condition* can change both the Intake tad axcratlco pattern but the body adjuate to Maintain ltt norasl latd balance. Distribution of lead In tbt body reTrail t low order of concentration of tbt slaaent la tbt toft tissue* other than tba liver with 0.0b to 0.2& ng/ 100 E* tad tba kidney vlth 0.01} to 0.16 Mg/ 100 The large*t latd depot la tba body la la tba akaletce where tba taount varies vlth different types of boot, being 0.21 to 1.11 &/ 100 ga In flat beat and O.67 to 3-59 */ 100 ga la long booa (5). Recent etudlee of 1}0 caeet by Tipton tad Cook (10) pointed out that there ym t vide variation la the latd content of til body tissues but the values obtained were la agreeasnt vltb those Keboe et el (11) reported 2} yatre earlier. Slallar result* have bees obtained by Puaba-vB et al (12) for bone tasplea obtained la the loe Angelas area. They found no correlation between lead concentration and tint of residence In the area tad no correlation between concentration and age In the 175 case* analyzed. Caparison of their reeulte and those obtained by others la given la Table 1. It eta be eeea that there baa bees little ebaaga la bone latd concentration over a period of 31 years wdien the uae of lead alkyls baa above eucb a large Increase (see figure 1). Thus, again the unavailability of the lead compounds la eutccct Ira exhaust la apparent, furthenaore. Boltrasa (l-l8) has shown that lead-210 froa the food-chain also appears la tba buaan skeleton as veil ae the soft tissues. LEAD TME5P0KT MO KgfAJOUSH After absorption Mostly via the gastro-Iciest leal tract, lead le carried to various tissues by the blood. The distribution of lead In the blood atreeua baa been shown by Keboe (5) to bet plasse, 0.001} ag/lOO c*l erythrocytes, O.C8b a*/ 100 pa or a total of 0.087 ag/lOO pa for whole blood. Recently the Lhlted States Public Health Service conducted a survey of blood and urinary lead aaoeg groupe of Individuals In Cincinnati, Los Angeles and (hiladelpfcla. {1?) Mean blood levels veret Cincinnati, 0.08) to 0.08} ag/lOCpsi Lee Angela#, 0.019 to 0.C81 ag/lOOpe ant Ihlladslfhle, 0.01) to 0.086 ag/100 pi. Urinary lead values veret 0.CC4 to 0.088 ag/Lj 0.0^ to 0.081 ag/L and O.C80 to 0.03) n*/L respectively. These data served to confirm those obtained earlier by Kehoe (}) Experimental Ingestion of lead at a ccnetaot level of 0.) ag per day`produced d o detectable elevation of blood lead in A20 days. After H years of Ingestion of 1 eg of lead dally the blood lead reached 0.0-4 ng/lCO ps. When the dally does was raised to 2 eg for.2 year# the blood value was 0.06} tg/100 pi and when Ingested l*d was increased to ) Mg dally for b es'Ei the blood level reached 0.0} eg/100 pa. Experimental Inhalation of air containing 0.1} Mg of lead/H* for J7.} hours per v*ak for ICO weeks Increased the blood level to O.b) ag/100 pa. Obviously both sxper taenia 1 lngastlon and Inhalation Increase blood lead levels but there was also a conccnlttaot locreaee in urinary lead amounting to 0.0)b to 0.U g/L after lcg*stlon to 0.71* ag/L after Inhalation. Hers agatQ the body vas adjusting to Increased lead Intake by Increasing lead acretloo via the kidney (20). There Is also Increased lead In the feces, the principal route of excretion, and this partially txplalna vby ttts vlth a controlled experiment it la wry difficult to Increase the body burden of load. . Another neohaniae exist* for decreasing the aaouat of lead la traoalt, namely, deposition la bone. HacDooald et al (20) have shown that both lead and stroetlua are bound to bens by adsorption or Ionic exchange at the surface* of bone salt crystal* or combined vlth the sulfate la the organic aatrlx. Sons seeking elements such as lead and strootlia are also discrim inated against by the kidney. lew Donald st al (21) have ahown that 'dien both calclua and stroctlun are available for skeletal retention, the kidney preferentially excretes the latter. LEAD mraxicmcw In the previous dlscussloo the various means whereby lead enters and exits from the body have been covered. In so Instance bas frank lead Intoxication been discovered la the thousands at cases discussed. This 1* probably, as bas been shown, due to lead balance la which excretion has kept up vlth Ingestion. When this balance breaks down, three ferae of lead Intoxication caa result) primary lntaxicatloo, characterised by Intestinal tract dysfunction, loss of appetite, constipation, colic and general aalalse aad weaknessj secondary Intoxication, characterlrsd by vsakaesa sad k m atrophy or even paralysis of the foreara extensor nueclssj finally, the lead encephalopathy frrT-sently seen la Infant* and children. In all three Instance* changes la besmtcpoleel* vlth basophilic stippling of the erythrocytes and reticulocytes are seen. The a*la esuses of lead poisoning In the population are Industrial exposure, burning of battery eases, eating of lead based paint, lngeettoo of lead Insectlclies, etc. Dangerous sxpeeure to lead give blood lead values ringing from 0.C7 to 0.2 a*/100 go and urinary values ranging from 0.06 to O.k atg/L. flealng (23) bas pointed out that the application of good Industrial hygiene practices has prevented any cases of lead Intoxication la the nanufacturlcg of lead alkyls in the last 30 years. Similar exemplary records have been compiled tor the other segments of the lead industry. Zveo cases of Inadvertent poisoning by lead have been reduced to very lov figure*, but no one caa guarantee absolute prevention of acute lead Intoxication la the population. Bowever, the dsvelopMQt of chelation therapy has prevented lethality and decreased the possible damaging effects of lead. Chronic lead Intoxication fras lnhalatioo of the breakdown products of lead alkyls has not been demonstrated In the 2)00 Individuals covered In the trl-cities survey coodss'ted by the Or. 1 led states Public Health Harries during the period Jun* 1961 through Kay l'/-? (19). Thus, again it becomes apparent that td cause lther acute or chruolo Intoxication the taxlo ag-nt must be In a fora that eon be readily absorbed and transported to Its target organs. Tbl* ha* not been demonstrated for ths decotpoeltlc* products of lead alkyl*. PUWT V It ha* been shown that the population of the United States 1* la lsod balance and the old cause# of acuta and chroolo lead Intoxication have bees reduced to very low level* by change* la technology. There 1* no such entity WMMJt -'.WiUJSS wsaaijwsesnqpfwv -5 - a* Mtural XmS body burden* becaus* tha population ha* been iipoJ to apyroxiaitely th* sane aaount at 1**1 In the eolld and lltpild copponent* at the diet tine* very early In tlae. The earth'* cruet contain* the lead which eventually enter* the body via the food chain and It ha* been shown. that, although people have been exposed to Increased concentration* of lead, caapeunda, these are cot available end the body burden ha* not Increased over the last 30 years. TABU 1 l e a d ccwcarmriog pt bo b* Klcrocraa* per Ores of Ash Tear 1933 1954 1957 flat Bon* 50-55 *eea -- 1941 196k 32 Long Bon* 55 ?6-5*> 69 Calvarltf* -- -- 74 * 65 r -- 7* M 63 r Bib -- 25-65 39 M 33 r -- 75 * eo r Pefereoc* 13 lk 15 5 12 M - Mala i 1 f > renal* * *- . 0 N Vv';i'w^'V' 'its* Wl? 1. ritUnod) C. C., Contt*lat*d tad Dtturtl l*td *nrirco**nt* of mb . Arch. Environ. H**lth U, 3W-360 (1965). 2. C*lltv*y,H. V., Load) A att*rial* rurv*y, Infcrnatlcc Circular 8063, Burttvi of Kin**, 0. 8. D*pt. of th* Interior, 1962, pp. 119-129* 5,'.. s-- 3. Blrtchltr, D. A., Ollbtrt, L. F., Itab, 7. V. tod Bltbylakl, L. K., Partlculat* laad coopouada la autoeotlr* xhtut {u, lad. Bag. Ch**. A2, UJ1-UU2 (1957). k. Xtbo*, ft. A., Benatl Mtkbolln of l*d, Arch. Environ H**lth, 8, 232-235, (196V). 5. Kaho*, R. A., Th* MtahollM of laad In eta la b**lth tod dlt*tM. J. ftcy. In*t. Pub. Bttlth By*- 2k, 81-97 (l96l). 6. >fcyr*ord, V. T., Turcar, 8. C. tad ftadlty, J. K., Alfiaa activity of c*rt*la botanical eat*rial*, Batura 187, 206-211 (1960). 7. Bill, C. ft., Iaad-210 tod Polonlv-210 In pul, JUturt I&f. 211-212, (I960). 8. Burt00, V. M. tad Stmart, B. 0., U** of toog-llvtd Datura! radio activity at to atao*jb*rte trac*r, Batura 160, 58^*59 (i960). 9. ft*=a, K.K. tod Ooldbtrt, B. D., Lead-210 la Dtlural vatara, Gotaoc* }*' *;<S it* 96-99 (l?6l). 10. Tiptoe, I. B. tad Cook. M. J., Trtc# #la*ot* la huona tlatu*. Part IX Adult ubjact* frot th United Stat**, Bttlth fhyile*, , 103-1^5 (1963). 11. K*ho, ft. A., Choltk, 2. tad Story, ft. V., A *pactroch**lcal ttody of th* aonatl rang** of ccoc*otratloa of cartala tract a*tala la biological BtUrltlt, J. Sutr. 12, 579-592 (19*0). 12. Butbtua, ft. B., Butt, B. X., Olleour, T. C. tad 1>1X>1o , 8. L., ftolatlon of tlr pollutlco to trtc* natal* la beat, Arch. Environ. Baaltb 10, 227-232 (1965). 13. Echo*, ft. A., thaataa, 7. tad Choltk, J., L*ad absorption tad *M ration la relation to dlagbo*l* of load poisoning. J. laduatr. Bn.'-15. 320-339 (1933). It, Tuapaatt, 0. L. rtralnat loo tad dUtrtbuttcn of lttd la hutta tl*u* tad iionU, Th* Aa*l/*t 01, 330-339 (1956). ;r fS* V- !-VjX- 5 -- ;*> 15. B*nd*r*ce, D. A. tad logit*, J. A., lttd coot*at of hoe* la obfontn Bright' dl**t**, Au*t, Aan. Md. L l.5-15k (1957). f r ygjgpyyfgj-wiigB..i2 * l j j j p .u mj m h. ^u. ^w a j m*** ?iTwu^iiimTwu"ir -Sit 91A Holtuaan. R. 8., Hea*ur*a*nt of th* natural coott of B*D (R> ) nd Raf (Po^10) In hioan boo* -- Eatlaatc* of vhol*-bo4y bur4*n*. B**1U fty*lc* 2 365-^ (1963). 17. Boltown, B. B., lb* *ourc of unsupported Po^IteP) la tUiu, BMltfe Phy*lc* 10, 763-76A (1964). 18. Holtn*n, H. B., 2UVb (FbJ)) la Inhabitant* of * C*rlbb*a Island, Sealtfc Jbyslcs 11, >*77-AflO (19&5). ' > 19. Surrey of L**d la tbs Ataosjbsr* of ttrs* Urban Ccmualtlss, RiS Publ. Bo. 999 AP-12, J. 1965, 9* PJ>. .t 20. Eebov, B. A., MatsbolU* of lead undar abooraal conditions, Arch, finrlroe. i Baalth 8, 235-2*3 (196*). 21. KwDcnald, I. 8., Busbaus, R. I., EalrlUa, f., Baxter*, B. C., 8p*ln, f. nod Bound*, D. I., Mtcbanlsa* In skslrtal accunulstloa of loo*. Arch. Blocbsa. Blophy. liS-126 (1953). 22. HscDonald, B. S., 807**, P. *nd Lorlck, P. C., Dtscrlxlnatloa of c*lclu and itrootlua by tbs kidaty. A*r J. Rgrttol. 168. 131*136 (l957) 23. rUoir*, A. J., Industrial hjrgWoa and **410*1 control procedure*. Arch Esrlron. Esaltfc, 6, 266-2J0 (196A). 1 J a;-'.., -v~ > - mjmjfjf. '^vvwiiw."