Document 4vzjzgLvX47gQJNdXjjEd1Mbx

LEAD INDUSTRIES ASSOCIATION, INC. 292 MAOISON AVENUE NEW YORK- N; Y. 10017 COPE 2>2 OR 1-4020 January 18, 1968 SUBJECT: "FACTS ABOUT LEAD AND THE ATMOSPHERE To Members of the Lead Industries Association, Inc.: Please find enclosed a copy of LIA's latest bulletin "Facts About Lead And The Atmosphere" referred to in our letter of January 8, 1968. Publication and distribution of this bulletin is one pnase of LIA's efforts to refute tne many claims made m the technical journals and the lay press that lead m the ambient air is reaching dangerous levels, a conclusion that is entirely without foundation as attested to by the factual data contained in the Bulletin. Various authorities including the U.S. Public Health Service are the source of the data contained. Of particular significance and included in LIA's Bulletin is a report published in 1967 based on findings of the World Health Organisation (WHO) of the United Nations. They stated that "the lead levels reported in the blood of the New Guinea aborigines are of particular interest in that these natives, living in the hills of New Guinea, away from industrialization and motorization, showed blood lead levels higher ir. range than urban and rural Californians. The mean figure of 22 micrograms per 100 milliliters of blood was higher than that of samples from 13 other localities, including California, Ohio and New Yorfc City, Mean levels from England. Yugoslavia and Finland are slightly higher than the New Guinea mean." It is hoped that members will use this Bulletin to advantage by personally distributing it to those people or agencies in their locality involved in air pollution control and more spe cifically those involved in setting ambient air standards for lea< Extra copies for this purpose are available upon request. 1S11098 Sincerely yours. f "Facts About Lead -Loo* danad tnhe Atmosphere" with L0*t David M. Borcina Secretary, Treasurer /' Contents Introduction Lead: An Essential Metal Measurements m Man Society Creates Wastes How the Body Handles Inhaled Lead Atmospheric Lead Measurements: Recent.Reaearch Findings Expanded Research Program References Tfitr coio* at this ea\<* daptlewtn thm at t$m4t--d ekromatt ytilaw p**t$ ia4 rrtiy* whan far tragi* martung mmd atkar rnfarp appUemttotu. Introduction / Industry and government, together with medical and research science, are today joining in a new massive effort to learn more about the myriad substances in the air around us and what they mean to our health and well being. Lead is one of those many substances. This* basic element is present m th air in extremely small quantities, us ually in the form of inorganic salts. All studies conducted by government, university.; or other research groups have shown that the levels of lead in the general or ambient air are low and do not constitute a health hazard. Nevertheless, certain pertinent ques tions; have been raised and studied. How much lead is in the air? How do the concentrations vary from place to place; and time to tune? Where does it come from? Does it contribute to '`smog!' formation? How fcuch lead does man breathe in? What happens to this? What proportion of lead in the geoerai environrocnt comes from the: air? What pan comes from li quids? From foods? What does re search science know about effects of lead on man? What effect does lead, in the air or elsewhere; have on man? What researches are now being con ducted? These and other questions will ibe discussed in this booklet. From existing research data and other information, it will be seen that lead in the air does not pose a problem for the public under present conditions or m the foreseeable future Yet care ful attention is being given and will continue to be given to all aspects of lead m the environment, mcludiof air-borne lead. The Lead Industries Association is constantly seeking to develop, assem ble and disseminate factual informa tion on the many aspects of lead and its uses in society today and to pro vide guidance on proper safeguards to be exercised. This booklet on "Lead and the Atmosphere" is one m a series being issued by the Lead In dustries Association. Readers are re ferred to the booklet. "Facts About Lead and Industrial Hygiene," fora discussion of the control of leal*in occupational exposures. * An Essential Metal Lead is everywhere. In the soil, tn the air. in the sea. It is in the bodies of city dwellers and in the bodies of natives deep in New Guinea's wilds, one of the most remote areas in the world, thousands of miles from modern civilization. Lead is the bask ingredient in the solder that binds together our elec tronic miracles and ts the sheath that protects our intercontinental com munication system. It is the barrier that confines dangerous x-rays and atook radiation. It is sound-proofing for buildings and ships and jet plana. It is the major component in the bat teries that start our can and it is in the gasoline that ruins our can. It is an essential metal that d too com monly taken for granted by the pubIk. Because lead is widely and essentially used in modern civiliza tion. there has been scientific interest in watching trends of lead in the en vironment and in people. Several re- PNYC00006569 cent studies, both in the United cades ... If there has been any drink, with a much smaller percent States and tn other countries, h*ve change, it would appear that at age coming from the air. Studies ha^e confirmed that lead m the general at* present man is exposed on the shown, however, that the actual quan mOsphere is at extremely low aver* whole to less lead in his environ tity of lead absorbed trom the normal age levels, about one-hundredth of ment than he was 20 years ago . . . atmosphere is so small as to be w- the concentrations sate for workers There is however no cause for lu.ally -undeteciableiand constitutes no in lead industries. These studies also complacency . . . " f3) hazard. checked, lead levels in pebp'le from, several population groups and found no indication of increasing body bur dens ot lead in the general public. Some Pertinent Observations These studies will be discussed m greater detail in later sections, but the following observations ar parti cularly pertinent; From the American Medical Associ ation's Committee on Occupational Toxicology i i 966): Recognized Facts Aboet Lead Lead' in the ambient air would be of little interest arid of no consequence if it were not for several recognized facts: People in general normally have small amounts of lead in their bod ies and each dav they take in and excrete tiny amounts of lead they get from food, beverage and air. The body is in "lead balance" un less an individual is subjected to an The question therefore is not whether there is lead in the environment or in the air or m people. The questions are whether the le3d thatjs present ^ of any significance to the health or welfare of people, and whether there is any likelihood that an increase tn lead exposure is possible and poten tially harmful. Fortunately, much authentic data exist O deal with these questions, and more research is in progress ip in crease our present knowledge, i "The Committee feels obliged to point out that as a result of yean of unusually high exposure for a con tinued period of time. (4) careful clinical study tn workers Over-exposure to lead can result in the lead industry significant, m lead intoxication, or plumbum, subtle, and unrecognized or un a condition which is becoming in recognizable' changes are not oc creasingly rare, mainly because of curring in the general population the protective measures m iead- as a result of us exposure to en vironmental lead. In fact, this vast produting-and-using industries, where over-exposure is most likely Measurements clinical evidence, evaluated by a great; number of climcallv trained to occur: Other than infrequent occupational exposure, cases of in Man scientists.; suggests that the general lead intoxication are rare and are Only in the past few decades has it public is not now, nor in the ten* considered accidental (Cases of been possible to obtain sound m* mediate future, facing a lead haz childhood lead intoxication occur formation about lead in man and 1 ard." (I) chiefly i among;; children in slum about lead in the environment. This d 4. T 5 From the U.S. Public Health Service publication. "Survey of Lead m the Atmosphere of Three Urban Com munities 'll 965): areas who sometimes eat leaded pamc chips from: old buiidinpThis type of abnormal situation does notInvolve) air-bornei lead and is being brought under control by is because of the development of the sensitive techniques of measurement and identification that are required to establish reliable information Armed with the necessary technology, "Data from (air samplings! show two courses of action: Non-leaded medical and research investigators are no consistent trend in the eoncen- paints are standard for building able to determine how much lead an trations.of lend in the atmosphere of the three cities during the past interiors, and urban renewal and rehabilitation programs are becom average man takes m. how much he excretes, how much he retains m 5 sears . . . (Blood lead levels) are ing more widespread.) his bones and various organs, how well within the presently accepted much is m his blood and his urine. 1 range of 1lead levels for humans and are not significant in terms of a threarof (he occurrence of lead intoxication within the groups.'4 <21 Lead particles, in varying sizes and quantities, can get into the air from various sources, including natural soil disturbances, the; burning of certain fuels, burning of waste materials containing lead, some These latter two measurements--m blood and urine--are the critical in dicators because it has been shown that an increase of lead in the blood .or urine signals an increased intake From the World Health Organization lead-using industries; and the com* of lead in the body from some i (1965): bustton of automobile gasoline. abnormal exposure. Industrial ex VI "There has been no increase in lead, The majority of lead* in the daily in perience has shown that a massive in crease in intake is required to eiev ate contamination in the last two de take of man comes from food and blood levels significantly, because the PNYC00006570 body retains little of the lead taken m. It has also been found that re moval of an individual from such exposures will bring his blood level back to a normal range. <5i As a re sult of increasing knowledge concern ing the erfccts of lead, and the use of proper controls in industry, there has been a marked decrease in the inci dence of industrial lead intoxications over the past 50 years: Data from Many Studies Careful studies oyer a long period have | produced the following facts pertitienf tO further dtscussibn of lead m thfe air;:,::(ia. 8): The normal person takes in. ex cretes and retains some of practi cally everv known element in his eating; drinking and breathing. American adults take in an average or about 330 micrograms of lead daily and excrete this same amount through normal body functions: thus the bodv remains in what is callHi:;Jleiiiid 'baianq?.^' There .is .no increase in leadj ih fHe 'ndrmll body with age. Most of the lead intake comes from food and drink: a very small per centage from air. Lead entenng the body from the air ranges from about 15 to 9Q micrograms per day. depending upon a number of factors, includ ing^occupation; place of residence and itype of lead in the air. Amount of lead in! blood of the average person will range from a low of about 10 to a high of about 50 micrograjne- of lend in 100 grams of blood, Most lead intoxication casta stud ied show a range from 150 to 800 microgrtim of lead per 100 grama of blood, and the lowest blood lead level associated: with illness has been, put at 80 mtcroframs, for either adults or children-Thii lat ter figure is usually taken as an indication (hat lead levels are get ting too high. An increase in lead found: in the urine is also an indication of greater intake of lead, indicating need for further checking, usually of the blood levels. The above facts have relevance in connection with studies which have measured the amount of lead in the atmosphere of American cities and in the blood of a number of selected population groups. Society Creates Wastes Since the beginning of time, both nature and man have sent gases and dusts into the air. which retains a remarkable facility for disposing of or dispersing them---mostof the time, in most places. But this ancient prob lem has acquired a new intensity be cause of mans constant crowding into city areas, his demand for the products of modem industry, and his society's creating more wastes than it is now prepared to dispose of readily. Because man creates wastes in almost everything he does, the complexities of dealing with the problems of air. water, and solid waste pollution are being increasingly recognized: Efforts to control and reduce man made contributions to air pollution in the United States are beginning to show results, according to data from the U. S. Department of Health. Edu cation and Welfares National Air Sampling Network (NASN). which checks the air in some 200 stations located in different parts of the country. The latest reported figures show that there was a slight, though sigmAcam, decrease in the average levels of particulates m the air measured from 1957 through 1963. (6)i Also listed are some of the things found among the suspended particulates, including such rpctals as arsenic.'chromium. copper, iron. lead, manganese, nickel, tin. uranium. vanadium, and rmc. Of lead, the NASN report said: ''At most locations less than 1 ^ of the particu late matter is lead." This indicates the relative quantitative role of lead m the overall air pollution picture. It has been demonstrated that lead has no role m the formation of photo chemical smog, which is one of the undesirable manifestations of air pol lution. (7) Neither NASN nor any other data show any general increase m atmo spheric lead m recent years. Currently, there is much interest in; the fact that about 99 percent of the gasoline used in automobiles in this country con tains varying amounts of lead anti knock compounds. When combustion engines, operate on leaded gaso&ne. some of the lead is exhausted into the air. Cars, of course, are not the eniv source: Others..are: Lead-using in dustrial processes; burning of waste materials containing lead; lead smelt ing and refining; ;and burning ot fos sil fuels. Alsol some natural sources contribute to lead in the air. <8> Modem GasotinesNeed Lead The use of lead is highly important to the efficient and economic production and consumption of the high octane fuels required by modern engines. Lead conserves the amount of crude petroleum required to' make the gasolines which assure smooth per* formtnee of automotive engines and improve i mileage:; Despite continued research and i the i itesting of manv other substances, no other material has been found m' effective. Lead anti-knock compounds were first added! to automotive gasoline in 1923 as a climax to a long and in tensive search! for ways to make a more efficient fuel that would elimin ate harmful ienguw knocki The public health aspects of the use of leaded gasolineiwcre investigated: and a.com mittee appointed by the U S Surgeon .General reported in 1926 that no hazard to the public health was mdicated from the use of leaded gaso line. (9) a similar committee m England' reported essentially the same in 1930; (10) PNYC000G6571 i 4 As a result of technological and eco nomic developments m the automo tive and petroleum industries, it was proposed in 195S that the maximum amount of lead anti-knock additives used per gallon of gasoline be in creased from three milliliters (about a teaspoonfuli per gallon to four mill iliters. The then L.S. Surgeon General named a committee to study the ques tion; and iri 1959 this committee con curred in the increase, fit l However.; the maximum is used in oniy.a small amoiint of ait gasOlines. and the aver age amount of lead in L'.S. gasoline in 196 7 is around 2:5 milliliters per gallon. What happens to the lead in the auto-^ mobile's gasoline depends largely on the drwtng pattern and speeds fol*! lowed, and the condition and design1 of the cars engine and exhaust sys tem, ft2) During sombutiion of guolini in the automobile engine, the lead anti knock compounds change to inor ganic salts, part of which are discharged ip the exhaust; Ip addition exceedingly small amounts of these lead aikayl compounds in organic form mav reach the atmosphere through'ithe escape of |j fuel vapors. St ill more are displaced from the tank during refueling, but these amounts arc so small they almost defy meas urement in the air. (2) / ZJ- i \ How the Body l_. * ' Handles inhaled Lead Studies to determine (he size and chemical composition of lead in the atmosphere have shown that a con siderable percentage of the lead ex hausted by automobiles settles quickly to the ground and is carried off by water or sweepings. Since most of these particles are non-soluble, those which go into water settle down rap idly and do not become waterborne, while others become part of the soil. Air disturbances, caused by winds, storms or autos, may stir up some of these panicles from tune to time. The finer particles become part of the part? iculate macter in the ambient air. and are the ones to which people are most likely to be exposed. fiJ. 14. U) However, man's breathing defense mechanisms prevent the majority of dust particles, whether carrying lead or not. from reaching or remaining m the lungs. Small dust particles (below 0.5 mi crons in; size: I micron equals 1 /1000 of a millimeter and is invisible) tend to remain suspended m the respired air and many are exhaled. Larger particles are filtered out in the nose. Approximately 90 percent of particles having an average size of IQ microns or Itrgcr tri removed in the nml tur passages. (16) Still lOther particles are cleaned out by the respiratory system's network of cilia--fine, hair-like structures which constantly sweep out the trachea (windpipe) and bronchi (air tubes) leading to the lungs. Any particles (including lead) that do reach the small air sacs ib the lungs are partially removed by scavenger cells called phagocytes. These engulf the panicles and carry them to a mov ing mucous layer by which they are moved upward by the cilia to the mouth. The quantity of lead inhaled ranges from less than 15 to 90 nncrograms per day (no doubt being closer to the lower figure, according to a long-time! researcher m the field) (8) Of that lead inhaled from the air. about 45 percent is exhaled immed ately The! lung clearance defense mechanisms carry another 45 percent of the total inhaled to the gastrointestinal tract for eventual elimination The remain ing 10 percent is absorbed into the blood, according to data derived from a lung dynamics task group of the In ternational Commission for'Radiation Protection. (23) Thus, in considering the effect of lead in the air on man. the amountof lead found in the air has to be weighed agamst the amount that a man may actually breathe m. retain and absorb This is very much less than ihe amounts m the air. ------ --- T"r Atmospheric Lead Measurements Measurements of atmospheric lead in cities during the past 20 years have shown low levels on the 'aver age and no definite trend upward or downward. In considering figures on lead in the ambient air. it should be noted that the present accepted safe level for in dustrial exposure to lead m air is 200 micrograms of lead per cubic meter of air measured over an eight-hour day. i.e., when the air of workrooms contains regularly not more than 200 micrograms of inorganic; lead per cubic meter of air. as measured by prescribed methods, cases of lead in toxication do not occur. (25) In Cincinnati. Ohio, reliable measure ments of lead in the air in different parrs of die city have been made since 1946. These measurements showed a downward trend in the mam residential and baste basin areas from 1946 to 1954. Since then they have stayed relatively steady:at below two micrograms of lead per cubic meter of air, Lead concentrations in the com mercial area: also show a downtrend from about four to two micrograms per cubic meter of air from 1955 to 1962. Reasons given for this decline since [946 are the diminishing uses of solid 'fuel, better collection and removal of the dusts and smoke from indus trial operations, better enforcement of smoke-abatement laws, and changes in traffic flow and land use in the metropolitan area. (17) PNYC00006572 This decline took place during a period when there wu about a two* fold increase in the amount of motor fuel used in the Cincinnati (Hamilton County) area and a nearly doubling in the number of can. During 19J4-55 an examination of lead-m-air data from .4 U.S. cities was made with the following ob servations: (17) In cities up to 2.0Q0.000 population, relatively low lead concentrations from 1.5 to % micrograms per cubic meter of air were found. In oues over 2,000.000 population, the ranges, of lead concentrations and the average amounts of lead ran higher, with Los Angeles at an aver* age (;medtan)|l^f' five micrograms per cubic meter the1 highest. The Three Cldcs Survey A detailed report on an extensive pro gram of lead-in-air measurements in three major cities was published by the Public Health Service m 1965. (2) The cities were Los Angeles. Cincin nati and I Philadelphia, and the report is commonly,iknown as the "Three Cities Survey/* The lead measurements were made from 3.400 samples collected from the atmosphere regularly1 over, the course of a year '(from iune 1961 through May 19621 from 20 different sues in the three cities. The findings were summarized in the report as follows: ' (. The annual average concentration of lead m the atnoapbere.ranged from about 2 micnsgraiM per cubic meter of air rn thedoirasown end industrial area of CinciMMtf, to about 1 in the outlying areas of that city. The values in corresponding areas in Philadelphia ranged from 3 to 1. and in Los An geles from 3 to 2. "2. The average concentration of lead in all of the samples obtained in each ctry was 1.4 micrograms per cubtc meter in Cincinnati. 1.6 in Philadel phia. and 2.5: in Los Angeles, j. The: highest concentrations of lead were found in the air during autumn and winter. The highest seasonal con centrations of lead at any station was 2.4 micrograms per cubic meter in Cincinnati. 3.8 in Philadelphia, and 4.1 in lej Angela, `4. The highest monthly concentra tion af any sue was 3.1 micrograms per cubic meter in Cincinnati (Octo ber). 4.4 m Philadelphia (October), and 6.4 in Los Angeles (December). "5. The highest concentration of lead in any one sample was 6.4 micrograms per cubic meter in Cincinnati. 7.6 in Philadelphia, and 11.4 in Los Angeles. "6. The mean concentration of lead found in heavy traffic ranged from about 14 micrograms per cubic: meter on Cincinnati streets through approxi mately 25 on Los Angeles Freeways, to 44 in a vehicular tunnel." (Ed. note: This particular finding refers not to the regular monitoring work of the Three Cities survey but to special Judies, using mobile samplers, in or near heavy traffic streams n Cin cinnati and Los Angeles, and to meas urements from another study done: in Boston:) "7. The average concent of lead in par ticulate matter for all samples was 1.7 percentin Cincinnati, l.j-in Philadel phia. and 2 3m Los Angeles, "S. Atmospheric lead concentrations varied dunng the day, hipest concen trations; occurred in die early morning. "The concentrations iof lead found in the atmosphere in this study were con sistent with those obtained during the same period by the National Air Sam pling Network (NASN) of the Public Health Service. Data from the NASN show no consistent trend in the con centrations of lead in the atmospheres of the threevcities during the past 5 yeamDataiiObtsinedhy the Kettering Laboratory vindicate; that in Cincinnati the trend has been downward since 1946." Though these data showed no trends in accumulation of lead in the air or of lead levels Jithat would affect the health of the public exposed to the air. it is `Significants that the report mdi- cates that such studies should be con tinued. saying that the results ''have established a baseline for future inves tigations of these types." The study itself wai prompted by i recommendation of the Surgeon Gen eral's committee, previously referred to. which in 1959 concurred in the in crease in the maximum lead content of gasoline. This committee recom mended that the Public Health Serv ice, in cooperation with industries, carry out : "...Studies to provide more defini tive data on levels and trends of at mospheric lead contamination in se lected urban areas and of the body burden of lead in selected population groups." (11) .. , Recent Research Findings In accordance with the latter part of this recommendation from the Sur geon General's 1959 committee, the Three Cities Survey in Los Angeles. Cincinnati and Philadelphia involved analyses of blood of approximately 2.300 persons and the urine of neatly 1.700 males within the same groups. (2) The persons examined were selected from groups such as policemen on traffic beats, service station and garage workers, commuters to and from sub urbs as well as non-commuters, and some persons with chronic illnesses. The results of this study showed many gradations in lead levels but no exces sive levels of lead in the blood or urine of those examined. Among the findings reported were: No relationship was found between blood lead levels and age. In a group of selected chronic dis- PNVCG0006573 ease patients afflicted with respira tory. kidney or bone conditions neither the range of values nor the mean iead concentrations in the blood or urine differed from the general population. These data showed neither unusually high nor low levels of lead in any of these diseased groups. Out of 'ifre-2*342 people studied, only f 1 showed blood lead levels equal to or higher than 60 micro grams per 100 grams of blood, and these It were from groups which probably1 had an occupational ex posure to lead - garage mechanics; traffle policemen, aircraft workers, etc. '*A few values in excess of 0.06 160 microgramsV are to be expected in a large sample of individuals rep resenting: a variety of exposures to leadi" the. report ojbserved. (A sub sequent follow-up on 7 of the 11 who could be rechecked showed char the lead iilevels on second mea surement had fallen into the normal range.) that special studies on this question "would be desirable.** Differences m the lead levels in the blood among the various groups in cluded in the Three Cities Survey are indicated in the tabulation below: Mean Blood Lead Levels lOf Selected Subnet Groupt in 'Three Cutes Surrey) 'In nucraframs per /OO jramj of bloody Lead in .Vo., Blood City and Suitea Group Subnets <**> Lead in So Stood City end Subnet Group Subnett 'Meant Lot Angeles: ClaHand Aircraft Employe** - .*? -^..PoBcemeti*^*: male female 2Si-.. \ I5_ * ; g?' * 17 smoteflr*:.-noo-smetW* 107 25 11 23 Policemen Pasadena dry* ~ "* IJFirwniilf0 ~ ** -- Urine" lead levels fell within the fairly narrow range that is defined as "normal.v The mean blood lead levels re-ported ranged from 11 mu iper IQQ grams a__ suburban non-smokarif-Tr*?' dclpltta:|to 38 microfi garage mechanics ihCti (checked previously in 1 is important to recognite differences betweetuUM highest of the ttveiy large, presently accepted resign at teed levels for humane and art net sig nificant.in term of a threat of the occurrence o lead intoxication within the groups/* the Public Health Service report laid. The-mean i concentration of blood lead in smokers was slightly higher thamthat of non-smoke/s. Leadi levels in blood of women ran shghtly"i lower than for males and the difference was "remarkably con sistent." No explanation for this was noted and the report suggests .. . .mife * 4^ : **. ------------ S $ '2* <0j Its- 1ST..- Other Smdks on Lead '*'TOO-grams of blood and mean urine . Jfcyeb of 27 ihtctogTBhs per liter of The Three Cities Survey findings were urine. (ltF_ _ consistent with other simitar, though, leu ambitious, studies in-the Urn Ifcl96fl, a study of 970 Americans in States as well as in other parts of the suc^Egpc^jeiiaid one rural area gave world. . - *1T,li-..! e these -fad&gsf .the mean for urban 20 micrograms of Vlaadi^thfryaifltpof blood as com- in 1943 a study of .188 Mexican end- * paced td *4 atfaugriim for the rural United States subjects showed me**-' blood samples. (19) Pertinent find blood levels of 30 micrograms per ings &em this study are summarized PNYC0C00657A Blood Lead Levels In fHu-rote-runit re' I1'" C'-amf at btoodt CVv Vo Sample! Wean New- Orleans 130 -i -i' Range 5.50 Dallas Denver Chicago 1.2S Id.' 3-54 131 19 7-5G: 97 20 5-60 New York i 12 20 4-53 Cincinnati Rural 137 20 3-51 102 14 1-35 An earlier study in Switzerland is of relevance because it included mea surements at two periods, one just after the introduction of lead antiknock additives into Swiss commer cial gasoline, the other about six yean later. 1201 The results: Swiss Study: Blood Lead Levtfe Averife Values Uicrofrwnt <uft per 100 framj of blood !9*4-19SO 19S3W93A u* pfoeit ug ptopi* Medical students 14 19 13 27 i No abnormal lead exposure) Oarage personnel 23 40 22 31 Thus, there was no change in lead con centrations m the blood during the tint six yean toUcwmg the introduc tion of leaded ggsolinc in Switzerland. < The slight ilurtUiie shown in the fig ures is not signdfam.) if? World Surety FMftjt The World Health Organization of the United Nations more recently sponsored an international task force study ot blood and urine measure ments collected from 16 nations of the world. The findings (published July 1967). averaged by country, showed average lead content in blood l rom a low of 7 micrograms per I (X)' milliliters of blood among urban Pe ruvians to a high of ZH micrograms lor urban dwellers in Finland. Aver age levels by residence, including urban and rural, reported in micrograms of lead per 100 milliliters Of blood, were: Finland 26: Yugoslavia 24. United Kingdom 23 : New Guinea 22: New York City 21: Czechoslo vakia, Egypt and Japan 20: Chile and California 17: Ohio 16: Israel and Holland 15:,Argemma 14; Italy 13: Poland 12: Sweden 10: and Peru 7. The aggregate average was 17. (21) According to Drs. Goldwater and Hoover of Columbia University, who reported the results of the WHO sur vey.: these and ocher recent investiga tions of "the lead concent m human blood do not differ greatly from those shown by older investigations during the past three decades.*' The Columbia scientists said that "the lead levels reported in the blood of the New Guinea aborigines are of partic ular interest rn that these natives, liv ing in the hills of New Guinea, away from; industrialization! and motoriza tion. showed blood'lead levels higher in range than urban and rural Califor nians: The mean figure of 22 micro grams per 100 milliliters or blood wan higher; than that of samples from 13 other localities including California Ohio and New YorkiGity. Mean levels from England. Yugoslavia and Fin land are slightly higher than the New Guinea mean:r* More detailed information from the doctor serving the New Guinea area revealed that (he environment is com pletely non-industrial jnd free of gas oline fumes 'Cooking is done m uten sils made of unfinished bamboo cubes. Other domestic utensils are mide mostly of wood These observations serve to illustrate the difficulties m assuming a simple relationship be tween residence and body blood lead levels." Fromi these studies and ocher exist ing data: 'it is shown that the quanti ties of lead detected in the atmosphere are well below concentrations that would present health concern to the public, 'are not increasing in general. and' are not elevating the body bur dens of the general public. In a recent review ot research on sources of lead entering the bodv. the ability of the body to achieve load balance, and the overall toxicology ot lead; a leading toxicologist m Cali fornia summarized as follows- i 22 j "It has been shown that the popula tion of the United States is m lead balance and the old causes of acute and chronic lead intoxication haw been, reduced to very low levels hv changes in technology. Lead bodv burdens of the population have been rnaima;iried at the Same ilevel for the past 30 yean regardless of the ract that there has been k 2.5-fold mfrease in the use of leaded gasoline: The bulk of the body burden of lead has been obtained via the food chain and not by inhalation from the environ ment. Although lead is present m the ambient iir. only a small percentage of the inhaled lead is in the correct particle size for pulmonary retention and1. rfjefr that. fraction contributes only an extremely small., amount to the body lead burden. Body detense mechanisms '.n-iakeilit'Highly unl.tkeK that environmental lead could induce chronic lead insult in the .population Greatly' increased exposure to lead slcj^lyl^plTeastt, the body burden but only en countered! nn the environment!. The supposed chronic intoxication from environmental contamination is j myth, hl&lpiifacit:'* -a Expanded Research Program Intensive medical studies carried out over a long period of time have estab lished sound criteria for determining safe levels of lead as found m the Jiet m industrial atmospheres and m man > system. According to known medical PNYC00006575 evidence, compiled from a variety of research tn the laboratory and on ani mal* and human beings, present levels of lead in the general environment do not present j public health problem. There remain questions about, lead in relation to human beings chat; should be investigated- The lead industry, which has long promoted apd sup ported such research, is expanding its efforts to study these questions. Re search studies into health aspects are included in the program ot the Inter national Lead Zinc Research Organi zation, Inc, ULZROb with which the Lead Industries Association is affili ated. ILZRO is now stepping up its efforts concerning investigations into lead and human health. One research project of immediacy and pertinence is seeking to determine the smallest amount of lead in air w hich man breathes that would have an effect on 't^ei^sitbleaccumulatjon. ot lead in the blood. Problem of Ambient Air Standards The pertinence of such research re lates to efforts by some air pollution control authorities to set ambient air standards: for certain substances which, in excess in the atmosphere, are considered pollutants. Setting such standards for lead at this time calls tor guesswork, when what is needed is solid information based on scien tific research. As has been said, in in dustrial exposures, the accepted safe level for a working lifetime: is 200 micrograine pet icutric meter of air in the workroom based on an eight-hour day. week. Obviously, this would no* necessarily apjrfy to air; which people ana breathing 24 hours a day. seve* days a week. Nor is it scientifically acceptable merely to as sume that since a full 161-hour week is roughly four times1 a 40-hour week, then there would be logic in setting the full-timelevelatabeutone-fourxh. or 50 micrograms per cubic meter of air, FulHime exposure compared with exposure and withdrawal fromi expo sure poses different problems in elim ination of lead!' Testa with Homes Subjects Kettering Laboratory at the Uni versity of Cincinnati is carrying on experiments with human subjects that involve nearly full-time exposure to atmospheres with known jead concen trations; The object is to determine what concentration of lead in the air a person breathes may start an up turn im measurable lead In the per sons blood. From this work, spon sored in parr by the U.S. Public Health Service, it is hoped that a reasonable yardstick can be developed for setting ambient air standards for lead, where desired, as is being done for many other substances found m the air. The fact that , there tt no scientific basis now for setting any such figure is conceded by the state of California which has been studying the situation for some yean and has not as yet found any acceptable method for de termining a lead/air standard, al-: though standards have been set for a, number of other substances emitted into the air from various tsources. During 1967. however, two states did adopt a figure for lead in the ambient air. despite admitted tack of founda tion, for these figures. The state of Pennsylvania set a 'tentative * limit of five: micrograms: per cubic meter of air averaged over a 30-day penod. Al though thts figure was said to be derived from preliminary data devel oped b> Dr Robert Kehoe of Ketter ing Laboratory. Dr Kehoe personally appeared before the Pennsylvania DepanmentofHealthheinngstodb* puce the application of hi* data in this way and to testify that research in its present stage showed' the figure to be too low. He added that anv figure calculated on present data "is not necessarily or even probably cor rect." (23) The state: of, Montana later adopted this same standard, upon recommen dation of the U.S. Public Health Serv ice. even though the PHS spokesman gave no scientific reason for this figure and told the: State Board of Health that: 'Information of the effects ot lead m rhe atmosphere is indeed sparse . As far as we are a*are. mere are no cases ot clinical lead poison ing that can be attributed to expo sure to lead tn the ambient atmos phere. the levels present,.*,- round m most places, are thought to be safe, although there are some places where exposures are subiect to con siderable question Allowing tor wtjde variability among individual persons, and a wide variability or exposures, and injecting a, nipdeSi factor ot safety, we teef that 5 micrograms per cubic meter or lead for monthly average ot exposure is probably safe." But nowhere did this spokeman give any data or backing tor this figure as against any other valucTwhether higher or tower. The human exposure studies which are, continuing at Kettering Labora tory are expected to shed; more sci entific '.ilijjiu on this complex subject when the experiments are completed. The question of whether the relati veiy small amounts of lead taken in by the average adult from air would have an effect on those particularly susceptible to disease has been at least partially answered by the Three Cities Survey in us study of patients with diseases affecting liver, kidney, lung pt bone. These patients showed no unusual blood lead accumulations. Stwdy of TEL Workers Another question that has been raised concerns exposure of long duration to relatively1 low levels of lead, such as might' occur in persons exposed to coming High levels of air pollution An analysis of the health records or penons occupationally exposed co lead for many yean does not indicate a correlation between such exposure and any ihealth problem. The results of one such thorough anal ysis w m reported at the October !9fi6 meeting of the Industrial Hygiene Foundation. (24) This was the study of employees in the tetraethyl lead (TEL) production facilities of a ma jor producing company. The TEL PNYC000C6576 group was suitable for this analysis because m addition to their normal exposure to lead, they were subject to some further exposure on their jobs: also, health data existed for the work* ers over their entire period of em ployment. The study covered 1,120 men: 348 currently working in the TEL area who had been there it* months or more; 348 men who had not had occupat ional lead exposure and who served ai contro(s; ind 424 men who had for*; meriy worked m the TEL area for at least six months or more tn the past. The fine two groups were matched according to race, age, and length of service with the company. Measure* ment of lead in urine excretions for TEL workers was almost double that of controls, showing a significant dif* ference in lead1 absorption between the exposed andiunexposed groups. Company medical records of the workers, were reviewedi for informa tion on ithe following items: history of important chronic rdisease; height and weight, blood pressures, hemo globin : determinations, white blood cell counts, apdi; electrocardiographic abKo'^rtiatii For the most common chronic dis eases. the TEL workers and prior TEL workers both showed lower preva' tence than that of the controls, the study/ound. The> summary of the findings said that thoughi.iiTEL1production'workers had an ; average unitary (cad exemioa: more than doubk-that of the general population, "nmradvant effect oci healthof this degreeof lead expocure was detected." - * Research WFieiide Answer*: The need for continuing research wu a consensus of the Public Health Serv ice symposium on environmental lead contamination held in December 1963 m Washington. A panel report noted that no ..explicit evidence -was pre sented: that suggested present lead bur dens were associated with any major contnbuoon to disease in the popula tion The report said the possibility References l.j-'H-i;- could not be excluded that present lead intakes might, in undetected fash ion, be related to certain ailments. The ! I. Committee on Occupational Toxico- panel recommended epidemiological l logy of Council on Occupations and laboratory studies to find but I Health. American Medical Associa- more about: possible effects of present \ non. Comment. Archives of Environ or higher lead levels oo man. Other recommendations included: More accurate definition of the effec I I | tive absorption of lead by inhalation: development of techniques for better assessment of body burden of lead, mental Health. 12:273. February 1966. 2."U.S; Public Health Service. Survey of Lead la the Atmosphere of Three L'r* baa Communities. PHS Publication No. 999-AP-12. January 1965. and "the biological mobility of lead in its several biological compartments, and continued, intensified studies on the relative contribution to the bios phere of lead from geological and 3. World .Health Organization. No In crease ia Lead Contamination Found by WHO Investigation, press release WHO 36, December 15. 1965. technological sources." 4. Kehoe. Robert A. The Harbea Lec- With these recommendations; the lead industry is in accord. It also expects that the research that it is sponsoring both alone and in participation with tm, 1964--Tbe Metabolism ff Lead laMaata Health tad Dbeaae. ournal of the Royal Institute of Public Health and Hygiene, 1961. other groups, or the work being done 5. Kehoe. i Robert A. Metabolism of by other organizations, will help pro Lend!:' Under Abnormal Conditions. vide answers to the questions that Archives of Environmental Health have been raised: 8:235-243. February 1964. The lead industry foe many yean has supported scientific studies: of all as pects of the use of lead. New and ex panded programs are continuing through the International Lead Zinc Research Organization. These include plani to participate in a major study similar to the Three Cities Survey pre viously described, but on an exptndedi: basis. Other projects will utilize new techniques, such as isotopic ratios, for measuring sources of lead in the en vironment. and will open up new av enues'or keening up with nfor-ation about mans use of lead especially about lead in the;'atmosphere. 6. U.S. Public Health Service. Air PolJatioaMeasaremeats of'the National Air Sampling Network--Analy s*s of Suspended Particulates, 1963: Robert A. Taft'Sanitarv Engineering Center. Cincinnati: Ohio, 7. Morris*. F.V.. Bolze. Calvin and Goodwm: John T. Jr. Smog Chamber Sredbes :o Unleaded versus Leaded FaelKiiiiii Industrial and Engineering Chemistry 50:673. April 1958. 8. U.S. Public Health Service. Symposlum da EariroaaMntai Lead Con tamination' (December 13-15. 1965) Public.. Health Service Publication No. 1440, March 1966. 9. U S. Public Health Service. The L ie of Tetraethyl Lead la Gasoline: Its Retedaa'iiilto^iPitbNc! Health. Public Health''! Bulletin No. 163. 1926. U). Final Report of (he Departmental CtMUhlN mi Ethyl Petrol. H<\ Maicsty't^Stationery; Office. London. 1930. IQ PNYC00006577 LI. U.S. Public Health Service. Pebtic Health Aspects of increasing Tetra ethyl Lead Content in Motor FoeL Public Health Service Publication No. 712. 1959. 21. Goldwater. Leonard J. and Hoover. A. Walter. Aa International Study of "NormaT Levels of Lead la Blood and Urine. Archives of Environ mental Health 15:60-63. July 1967. 12. Hirschler. O.A.. Gilbert. L.F.. Lamb. F.W., and Niebyl&ku L. Particulate Lead Compounds in Automobile Ex haust Ga*. Industrial Engineering Chemistry 49:1131-114.2. 1957. 22. * Haley. Thomas J, Chronic Lead In toxication from Environmental Con tamination: Myth or Fact? Archives of Environmental Health, Vol. 12. June 1966. IJ.* Robinson. E. and Ludwig. F.L. S4xe DbtrilNidoa of Atmospheric Lttd Aerosols. Stanford Research Institute. MenJo Park. Cal., 3b pp.. April 1964. 2J.'Kchoe^ Robert A. Testimony at Hear ing of Pen--ylvaaia Depart--eat of Health. Harrisburg. January 19. 1967. 14. Cannon. H.L. and Bowles* J.M. Con tamination of VtftOdoe by Tetra ethyl Lead. : Science 137:765-766, 1962. 15.,a Robinson. E.. Ludwig. F.L.. De Vries. and Hopkins. T.E/ Var* iatfcoa of Af--oapheric Lead Con* ceatratioa and Type With Particle Size. Stanford Research : Institute, Menlo Park. Cal.. 80 pp., November 19631. . 24. Stopps, Gordon J.. Maxfield. Mary E.. McLaughlin. Martha, and Pell. Sidney. Lead Re*earth: Cormt Med* I--I Develop--eata. Presented at 3lu annual meeting of Indiatrial Hygiene Foundation, Pittsburgh, Pa., October (8-19, 1966 25. American Conference of Govern ment Industrial 'Hygienists. 1014 Broadway, Cincinnati, O. 43202. Threshold U-fc Values for 1947. (6. Hatch. T.F. and Gross. P. Psbaoury Deposition and Retention of Inhaled Aerosols. Academic Press, New York. 1964. 17. Cholak. J.. Schafer. L.J.. and Ster ling, T.O. The Lead Coate-- of the At--oephere. Journal of the Air Pol lution Control Association 11(6): 281-288. June 1961. 18. Cholak* I and Bambach, K. Me-- re--et of M--rial Lead rip-- by Analyses of Blood and Exert-- ef Wocfc--ea, Journal of Industrial Hy giene and Tcxicotofi.25:47-54, 1943. 19. * Hofreuterv OJ& Catoocv EJ^ K*fr> nin.R.G., ad' XEauru^ C. The PiMk HteMI %dBcski ef At--aepherte f --4rA--hh-- of Environmental Health 3:564-574,1961. 20. Report of the Swim Leaded GahoHae C--ahdM to the Federal Conad ou Its Activities Daring the Petted 1947*1940. Mitteilungea aus dem Gebtetc ; der Lebcnsmiueluntenuchung und Hygiene (Bern) 52(3):13S244: 1961. Other References "Lead Industries Association. Inc.. New York City. Facta Abo-- Lead and fad--trtal Hygkae. 1965. Task Group , on Lung Dynamics for Committee IL Health Physics 12(21:173-208, 1966. Ncwsholme* A. The S--ry ef Modem Preventive Medftdse. The Williams and Wilkira Company, 1929. Afc PaBadoa. World Health Organi zation ii Monograph Sen-- No. 46, Columbia University Press, New York, 1961. "Schroeder. H. A. and Balassa. J. J. Abnormal Trace Met* te M-- Lead. Journal of Chronic Diseases (St. Louis) l4<4):408-425. October 1961. Bagchi. K.N., Ganguly, H.D.. and Sudor, J.N. Lead hi Food, Indian Journal of Medical Research 29:441* 450. 1940. Warren. H.V. and Deiavault. Observations oa the Biogeocb* try of Lead in Canada. Transac of the Royal Society of Canada 520. I960. Warren. H.V. Trace Elements Epidemiology. Journal of the Co of General Practitioners 6:5171963. `Ziegfeld. R.L. Importance tad I of Lead. Archives- of Envrronme Health 8:202-212. February 1' Damn. W.K. and Haffty. J. Oc react of Minor Elements In Wa U.S;- Geological Survey, Circi 445,1961. Kehoe. Robert A. Normal Metal tarn of Lead. Archives of Envir mental Health 8:232-335. Febru 1964. j Nusbaum. R.E., Butt. E.M. and C mour. T.C. Trace Metal Studies Boat hi Relationship to Air Pol Cant Exposure. Archives of Envm mental Health 10:227.232. Febru; 1965. Lane;; R. Health Control la fnorgst Lead Indatfrtes. Archives of Envirc mental Health 8:243*250. Februa 1964. CaJaodra, J. C. Lead la the Enri oa--eat. Presented at 38th annu meeting of The Lead Industries A sociatmn, Inc.. Sc. Louis. Mo.. Marc 31-April 1. 1966. Patterson. C.C. Coe--fnated aa Natural Lead Eavtroa--eats of Mai Archives of Environmental Healt 11:344: i September 1965. Kehoe:! Robert A.. Thamann. Free enck and Cholak. J. Oa the Nor--i Aheorptioa and Excrvtioa of Le-- L Lend Absorption a*d Excretion l Pi Unlit.re Life. Journal of Industrn Hygiene 15.257-272. 1933. *A vailablt from The Lead Industrie. Association* Inc. PNYC00006578