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Final Report FOOD CHAIN AND HEALTH IMPLICATIONS OF AIRBORNE LEAD By John R. Goldsmith, M.D. Epidemiological Studies Laboratory State Department of Health September, 1974 This report was submitted in fulfillment of Contract Number ARB - 012, Project Number 7-Q83~l, of the California Air Resources Board. N27630 TABLE OF CONTENTS List of Tables ..... .. , . . . . . . .... . Acknowledgements ............ ................... Conclusions* . * * . * * *, ,, . . . . * . * . Recommendations. ................. Body of Report . . * ........ .. . . . . 4 5 6 8 9 I. Introduction and Narrative History ...... 9 II. Concurrent Research Activity and Its Relevance 12 A. International Symposium on Environmental Health Aspects of Lead, Amsterdam. B. Occupational Health Study in Smelter Employees C. "Seven City Study" 0. Manuscript on Vegetation Monitoring E. El Paso Smelter Study III. Laboratory Methodology . . . . . . . . . . * .15 A. Analytical Methods B. Inter!aboratory Comparisons IV. Choice of Communities for Study. . . . . . .. . . ..19 V. Sampling and Collection of Human Specimens ... . . .21 A. Adults B. Children VI. Population Sampling Results. . . .......... 24 A. Raw Data B. Analysis and Interpretation VII. Environmental Sampling Results ..... . .... . 28 A. Raw Data 1. Food 2. Air Monitoring 3. Avena Sampling 2- DUP040008515 FOOD CHAIN AND HEALTH IMPLICATIONS OF AIRBORNE LEAD Air Resources Board Project: 7-083-1 September 30, 1973 Abstract In January 1970, lead poisoning among horses In the Carquinez Strait Area led to questions as to whether lead In air might be affecting human food supplies in that area or elsewhere in California. This added further urgency to the Department's interest in seeing whether sensitive methods could be applied to distinguishing blood lead levels in population samples of California adults and children. Air samples and food samples reflecting usual local purchase and con sumption habits were obtained in five areas; one an isolated mountain community and two paired communities each in the San Francisco Bay Area (Martinez and Crockett) and in Los Angeles (Manhattan Beach and Burbank). In addition, blood and urine samples from adults and children were ob tained and analyzed for lead or for metabolic evidence of lead exposure. The first hypothesis tested was that there Was a relationship between ingestion of lead by humans -through food chain mechanisms and blood lead levels. The second hypothesis tested was that there was ah important association between airborne lead levels, and lead levels in blood or evidence of impairment of biochemical processes through the effect on delta-amino-1evilinic acid dehydratase. Supplemental support permitted further studies of the factors influencing lead levels'in the blood of children in Los Angeles and in San Diego. We found no appreciable contribution of food lead levels to lead body burden as reflected by blood lead or other bin logical indices. We found blood lead among school, children In Burbank to be significantly higher than In Manhattan Beach, and blood lead among adults to be higher in Crockett than in Benicia. Air samples from Burbank also showed higher concentrations of lead than did those from Manhattan Beach. We did not find any evidence of high blood lead levels among children in San Diego who lived in older housing. We recommend further monitoring of lead in children in relation to atmospheric exposure and to other sources. We recommend further application of vegetation sampling (Avena) as an indicator of particulate metalic pollutant. -1\ DUP040008516 LIST OF TABLES 1. Household Semples and Successful Contacts 2, Summary of Laboratory Results, Specimens from Adults 3. Summary of Lab oratory Results, Specimens from Children 4. Comparison of Lead Concentrations i n Food by Area '(a) 5. Comparison of Lead Concentrations in Food by Area (b) 6. Comparis on of Lead Concentrations in Backyard Garden Produce by Area 7. Summary of Air Sampling Data 8. Blood Lead Concentration by Location and Sex, Six-Community Study of School Children, Southern California 9. San Diego County Study of School Children, Comparison of Mean Blood Lead Concentrations -4- DUP040008517 prr' r B. Analysis and Interpretation 1. Food Chain Hazards 2. Air Monitoring 3. Avena Sampling VIII. Strpplementary Studies of Children . . . , . . . . . 34 A. Six-Community Study in Los Angeles B. Housing in San Diego > IX. Appendix. ..................... 37 A. Raw Data-Environmental Sampling Results 1. Food-Lead Concentration a. Ordered by Food Code Within Area b. Ordered by Food Code Within Area Within Food type c. Ordered by Lead Values Within Area 2. Air Monitoring-Lead Concentration by Day a. Benicia and Crockett b. Burbank and Manhattan Beach 3. Concentration of Lead and Cadmium in Avena, Manhattan Beach B. Raw Data-Population Sampling Results C. Laboratory Methodology 1. AIHL Method No. 20 2. AIHL Method No. 41 3. AIHL Method No. 42 4. AIHL Report No, 37 v 5. AIHL Report No. 161 6. Prpic-Majic, D. ; P. K. Mueller; V.C, Lew; and S, Twiss: 6-Aminolevulinic Acid Dehydratase (ALAD) Stabil ity in Human Blood, Am. Ind. Hyg. Ass. J. 34:315-319. D. Manuscript: Thornton , S.A.; Stanley, R.L.; Twiss, S. ; Brandford, P.; Goldsmith, J.R.; and Mueller, P. K. : Vegetation Monitoring for Airborne Heavy Metal Pollu tion , Unpublished. U -3- DUP040008518 A ACKNOWLEDGEMENTS State Department ol' Public Health Environmental Epidemiology Unit: Margaret Deane, Biostatistician Monroe Garnett, Research Assistant Sydney Thornton, Plant Pathologist Madeline Thresh, Survey Interviewer Air and Industrial Hygiene Laboratory: Peter Mueller, Ph.D., Chief Robert Graul, Assistant Chief Hezekiah Moore, Spectroscopist SuzAnne Twiss, Statistician Danica Prpic-MaJic, Research Specialist Jordan Kyono, Chemist Virginia Lew, Chemist Dan Uchimoto, Chemist Sandra Kerns, Chemist Sylvia Hope, Research Assistant Gregory Markowski, Research Technician Tuberculosis and Respiratory Disease Association of Los Angeles County: Stanley Rokaw, M.D. Edward Ot oupalik San Diego County Health Department: Donald Ramras, M.D. v Raymond Redmond, R.S. Ella Louise Gilmore, P .H.N. Staff, students, and parent volunteers of the participating schools in Manhattan Beach, Burbank, Benicia, Crockett, Lan caster , Oceanside, Long Beach, R.iverside, Culver City, and Azusa. Community participants in Alpine County, Benicia, Crockett, Manhattan Beach, Burbank, and San Diego. DUP040008519 In general, biochemical teats and urinary lead, where available, support these contrasts. In Alpine County, the blood lead values in adults are as low as any populations included (within measurement error), but are not much lower than urban samples, as was also the case in our study there in 1960. While our laboratory testa of high volume filters agree with samples split with the Kettering Laboratory, our blood lead values are significantly lower (Figure I). -7 DUP040008520 ........ --BF--- CONCLUSIONS The conclusions are based on Tables 1, 2, and 3, appended. Raw data for environmental, food, and biological reactions were submitted earlier, A, Food Chain Aspects Food intake as determined by dietary history in each of the five communities was sampled by purchase from local grocery stores and by "backyard'' garden samples. The highest lead value was in carrot greens (not usually a human food), followed by other leafy vegetables; the highest value in meat was in veal kidney (probably not used in quantity). No important differences by area occurred. Canned milk has enough lead (even When diluted 1:1) so that it could contribute an excessive amount to infant ingestion. We find no evidence that in areas polluted by lead sufficient to poison horses. human inges tion of lead through food chain mechanisms la a public health problem, B, Health Hazards When men and women in Benicia and Crockett arc compared with respect to blood lead, the Crockett populations have significantly higher values. The sources may have been via food in the past or it may. r reflect respiratory exposure^ It was not due to occupational expo sure, for occupationally exposed individuals were not Included, ^~TiTe~le've 1 s observed were not in the range likely to be clinically ; \ Important,/' No significant differences "in blood lead in children xfrom"Benicia and Crockett were noted. Significant differences in blood lead from both male and female children Were observed between Burbank and Manhattan Beach. Burbank boys have mean blood lead slightly greater than 23 yg/100 g and girls greater than 20 Pg/100 g, both of which exceed the "acceptable biological limits" proposed for groups of children byZielhuis. It fhoirlcTbe^'noted that the California laboratory methods'may not be strictly comparable with those used in defining the .Zielhuis stand ards. Also, the California blood lead results are reported in yg/100 g. These should be multiplied by a conversion factor of about 1.05 to give results for comparison with the Zielhuis standards, which are expressed as yg/100 ml. Among preschool children in San Diego living in houses which are positive for lead paint, no exceptionally high blood lead levels were observed. The highest reported value was 31 yg/100 g. No relationship was found between blood lead levels and concentration of^lead in dirt from play areas. The limits for individual blood lead levels (>40 ng/100 g) were exceeded for tyo out of twenty maleft adults In Crockett. ------ f v_.. \ 6- - DUP040G08521 RECOMMENDATIONS. Studies of the association of childhood hyperactivity and probable lead exposure should be undertaken in Los Angeles* Further studies of children can give useful validation to the scanty data reported here. Results of studies of blood lead levels and biochemical indices, especially in children, are a useful guide to the magnitude of pollution and the need for control. Measurement of lead and other contaminants in vegetation samples provided a useful supplement to high-volume air monitoring. The results reported here In our opinion suffice to indicate the urgent adoption of policies on local, state, and rederal levels to meet as soon as possible the Air Quality Standard tor read. 8- - DUP040008522  "N, I, INTRODUCTION AND NARRATIVE HISTORY OF THE PROJECT The California State Health Department first focused on the Community exposures to lead in 1959, in connection with the first report on ambient air quality standards. At that time, the fundamental research of Professor Kehoe had provided guidelines which indicated that "absorption from all routes of 120 micrograms of lead a day might be harmful, while a total of 66 micrograms is presumably safe". Blood levels for lead appeared to give a sensitive indication of the poten tial toxicity. Based on data at that time available, it was indicated that the possible air pollution standard might be 6 micrograms per cubic meter. It was understood that community air pollution exposure should be allocated only a portion of the allowable body burden as estimated by absorption or excretion. At the same time, (1959), the industries using lead in motor fuel, were requesting the Surgeon General of the Public Health Service to evaluate a proposed increase in the maximum amount of lead in motor fuels from 3 milliliters per gallon of ethyl fluid to 4 milliliter per gallon. In the course of this evaluation, additional data came to light concerning the proportional retention in the body of lead of a particle size likely to occur in community air pollution. Accordingly, a number of health authorities undertook tovactively study the extent to which elevated levels of blood lead could be associated with the atmospheric exposure variations in different parts of the country. This resulted in the so called Three City Study (1965), which documented the substantial and persistent excess of lead in urban dwellers as opposed to blood samples taken from rural populations. The set of results from the Three City Study indicated that with increasing respiratory exposure, there tended to be Increasing blood levels which presumably reflected respiratory exposure and body burden increases. A number of requests for studying populations living near California freeways led to a study being undertaken in 1966"to determine whether people living near a freeway had a higher concentration of blood lead than that of people living at some distance. Samples of blood were taken from two groups of 50 persons each. The homes of the first group were adjacent to a heavily traveled freeway, and in the second, near the coast, in an area with substantially less atmospheric lead. There was found to be a consistently significant excess of blood lead among the populations living near the freeway, independent of age, sex or ethnic status. However, the values observed did not deviate markedly from the values found for other populations in the Los Angeles Basin. The significant finding was that the population living along the sea coast had lower values than other population groups. -9% DUP040.00.8.523 f/ In 1967, there became available experimental human exposure data that reflected the range of exposures similar to those occurring in community air pollution. Goldsmith and Hexter thereupon published a paper proposing that there existed a statistically significant increase in body burden of lead in male populations that was associated with increased respiratory exposure to lead. Following this, the Department set about the process of using such findings as a basis for air quality standards. In 1969, the Department proposed such standards in a seminar at the Air Pollution Control . Association. In 1970, standards were proposed by the Department to ^ the Air Resources Board. A standard of 1.5 micrograms per cubic meter, based on a 30 day average was recommended and after public hearings, was adopted. In the meanwhile, the federal air pollution research groups in collaboration with the American Petroleum Institute, and the International Lead-Zinc Research Organization was undertaking the so-called "Seven City" Study., the results of which have not been published though they have been widely quoted by industry representatives. Between 1967 and 1970, the Department repeatedly sought to obtain funds from the Federal Government to study the blood lead levels and biochem ical indices of California populations who, on the basis of previous work, were expected to have lead exposures of differing magnitude. The efforts to obtain research support were without avail. \> Between 1967 and 1969, the Department received contract support to evaluate air quality criteria and make recommendations to the Federal Government, and a portion of the work involved, the collection and organization of information about lead. The National Academy of Sciences-National Research Council, however, appointed a panel to consider lead in perspective and the further support of work toward air quality criteria by the Federal Government was held in abeyance. In January 1970, the Department of Public Health and the University of California School of Veterinary Medicine were asked to determine the cause of death of horses in pastures vin southern Solano County. Pre liminary work indicated the horses had died of lead poisoning and that other animals in the vicinity had elevated levels of lead in blood and hair samples and in tissues. Atmospheric sampling at the same time did not give evidence of unusually high exposures, though there were several large sources in the area which might have been contributing, including traffic over the Carquinez bridges, and the Selby smelter. Between March of 1970 and November of 1971, the State Health Department and the Air Resources Board, with the assistance of other agencies, carried out a study on lead contamination relative to horse deaths in southern Solano County. This study utilized a systematic sampling of lead levels in Avena fatua which was developed in the Department. This permitted the deter mination of gradients that fit the estimates of exposure and dissemination. It was based on analysis for two substances, lead and cadmium. 10\ DUP040008524 r In recognizing that the pastures in the Carquinez Strait area were widely contaminated with lead and cadmium and other metals, the stage was set for concern that other food sources were contaminated as well, and this became one basis for the proposal which led to the present research* In early 1971, the Department put forth a proposal to study both the food chain and health effects of air-borne lead* This proposal, was accepted and initiated on July 1, 1971. The continuation and completion of the work on vegetation sampling in relation to Benicia, Crockett and the Selby smelter, was carried On with support from the Air Resources Board during the period of study. The plant pathologist, Mrs". Thornton was able to assist us in ob taining vegetation samples, and backyard garden produce was obtained in as many places as possible. Initial community studies were carried out in Alpine County cooperatively with the Kettering Laboratory, which was supported by industry and by the Federal Government. Benicia and Crockett were studied in northern California, and Manhattan Beach and Burbank were studied in Southern California. While the work was underway, and without notifying us. Dr. Tepper made available the data from the blood samples in Alpine County, and they were used as evidence against proposed regulations of the Environmental Protection Agency. The lack of agreement between the Kettering Laboratory results and our results for blood lead is to be contrasted with the agreement between air samples obtalned by the Kettering Laboratory and analyzed both by their laboratory and ours. The organization and conduct of an international symposium on public health aspects of lead occurred at a time which has permitted the development of acceptable levels for tentative population exposure, and this is covered in Section II. At the end of the study period, it is still not possible for us to look forward with certainty to control of the emission of high amounts of lead from motor vehicle exhausts, which is necessary to meet the State's air quality standards. L- -11* DUP040008525 c L- II. CONCURRENT RESEARCH ACTIVITY AND ITS RELEVANCE A. International Symposium on Environmental Health Aspects of Lead, Amsterdam At this meeting jointly sponsored by the U.S. Environmental Protection Agency and the Council of European Communities, current research was presented and appraised. There were several highlights of the meeting. Biochemical indices''were found to be useful; ALAD was recommended as the most sensitive test and appropriate for estimating community exposures in a range capable of derangement of hemoglobin synthesis. However, the importance of such derangement to health has not yet been fully evaluated. ~ Dr. Zielhuis, from the Netherlands, proposed acceptable biological limits both for individuals and for groups, and for adults and for children. These included lead in blood (PbB), amino-levulinic acids in urine (ALAU), and amino-levulinic acid dehydratase (ALAD). These values are shown on the next page. Provided that groups are repre sentative and include at least 15 persons, and that the methods used are standardized, the participants accepted these as guidelines. In comparing the results of the California data with them, however, it should be noted that there is a conversion factor of about 5% between pg/lOOml (used in the Amsterdam recommendations) and ug/lOOg used in the California study. Also, the methods used may not be strictly comparable. Excerpt from: LEAD ABSORPTION AND PUBLIC HEALTH: AN APPRAISAL OF HAZARDS by R. Zielhuis International Symposium: Environmental Health Aspects of Lead, Amsterdam, October 2-6, 1972 Acceptable biological limits v Environmental standards have to take into account total daily uptake; this can be measured indirectly by biological monitoring of PbB, ALAD and ALAU. Particularly for more or less homogeneous groups one may conclude to acceptable biological limits, characterized by group averages and upper limits; for individuals one may present upper limits. These limits should not be regarded as fine lines discriminating innocent from nocuous environments; however, if these limits are exceeded, the possibility of undue acute effects and/or chronic sequelae increases. The data as established in population groups should always be interpreted by experts, and not by the lay public as such. Single values moderately exceeding upper limits in individuals should cause awareness and caution; the measurement should be repeated. Group data have a stronger signifi cance than individual data. -12- v- DUP040008526 reduced amounts of hemoglobin. The hypophospatemia was- "consistent with disturbed function of the proximal renal tubules and failure to reabsorb phosphate'1. It may reflect damage by cadmium or lead or a combination. Since it occurs in an area also covered in our study, this work provides a useful basis for reference. However, persons with occupational exposures were excluded from our studies. C. "Seven City Study" This study.generally confirms that urban women have higher blood lead levels than rural ones, and that smokers have higher values that nonsmokers, It suggests that with increasing urban lead levels, there is increasing lead storage, although the gradients do not appear to be as steep for women as for men. Inclusion of Los Alamos {elevation 7,300 feet) implies an expected high hematocrit, and the role of this factor is not appraised either in the draft report on the "Seven City Study" or in interpreting results from Alpine County. fecal lead measurements were made, partially to test the allegation that previously observed differences in blood lead were due to dietary differences. No data supporting this allegation were found. This is similar to our study's finding of no appreciable differences in lead intake in market^purchased foods in the several areas. (Environmental Protection Agency, "A Survey of Air and Population Lead Levels in Selected American Communities", EPA-R1-73-005, December 1972.) D. Manuscript on Vegetation Monitoring During the period of support, we completed a manuscript for publication entitled "Vegetation Monitoring for Airborne Heavy Metal Pollution" (appended). This proposes a supplemental monitoring system, one which has also been applied by Kalman and Graham at Stanford, who also are publishing supporting data from Palo Alto. E. ' Studies of Environmental and Population Exposures in the Vicinity of El Paso, Texas Smelter, The U.S. Public Health Service has been studying lead levels in individuals living near a smelter. According to a preliminary report, highest levels were found among children 1-4 years old living within 1 mile of the smelter (42.4% > 40 pg/100 ml). Air samples within 1 mile showed significantly high values (annual mean 8-10 u lead/ra^). A relationship between blood lead levels and concentration of lead in house dust is demonstrated by the finding that children within 1 mile who had levels < 40 pg/100 ml were exposed to 3,5 times amuch lead in dust as those with lower levels (6,447 ppm versus 2,067, p<0.0001). The revelance of this to our work is that it confirms the inadequacy of air sampling as a basis for health risk estimation in the vicinity of point sources. The population sampling data obtained in Benicia and Crockett do not 'indicate an exposure of the level of severity apparent in the preliminary data from El Paso, A preliminary report of the El Paso study is available from the Center for Disease Control, Atlanta, Georgia, An article is being submitted for publication in the New England Journal of Medicine. -14- DUP040008527 The following acceptable limits are suggested as guidelines: For adults individual upper limit group average ' unit PbB ALAU ALAD 540 <6 >20 525 pg Pb/100 ml < 3 mg/1 urin >30 procentual decrease from 100% Cat PbB *= 10 pg Pb/100 ml) For children individual upper limit group PbB ALAU ALAD <35 55 >30 <20 <3 >40 as above it tl The Environmental Protection Agency input to the meeting emphasized its concern about the contribution motor vehicle emissions were making to the exposure, uptake, and lead burden in children. There was no clear agreement as to the risk or contribution of air' pollution to lead toxicity in children. Professor Truhaut reported on a joint expert committee of the Food and Agricultural Organization/ World Health Organization concerning food additives, which evaluated toxicology of lead. They established in adults, based on the assumption of only 10% of ingested lead from food and water being absorbed, a provisional tolerable weekly intake of 3 mg. lead per person, equivalent to 0.05 mg/kg body weight. This is equivalent to 3000 x 10% = 300 micrograms per week or 42.8 micrograms of lead absorbed per day. The experts went on to say that "Any increase in the amount of lead derived from the drinking water or inhaled from the atmosphere must decrease the amount which can be tolerated in food. The contribution of lead in air is probably the one most accessible to action for reducing the total body burden of lead, especially where this fraction is large compared with that absorbed Itom food.'1 "' '--' This position supports the complementarity of food and air pollution as important routes in ingestion. B. Occupational Health Study in Smelter Employees At the Amsterdam meeting, Cooper, Tabershaw and Nelson reported follow-up studies of former employees of the Selby smelter. An unexpected finding was a depression of serum inorganic phosphorous in individuals with blood lead levels above 40 pg/lOOg of blood (i.e., those with little or no lead exposure were normal). Higher blood lead levels were associated with -13- % ov DUP040008528 - -V XIX LABORATORY METHODOLOGY A. Analytical Methods During this study several methods were adapted by the Air and Industrial Hygiene Laboratory for the analysis of lead in biological specimens, food-stuffs, and air. Blood specimens were also analyzed for amino levulinic acid dehydratase (ALAD) and urine specimens for aminolevulinic acid (ALA). A concurrent study was conducted to optimize blood sample storage conditions to assure the stability of the ALAD. 1. Lead in Blood, Foodstuffs and Air Blood samples were analyzed by two atomic absorption methods: the methyl isobutyl ketone extraction (IBK) method of Yeager, Cholak, and Henderson(f) and the Delves method(2,3). Samples collected early in the study were clotted and had to be analyzed by the MIBK method. Subsequent samples, thoroughly mixed with heparin in the field. Were analyzed by the more rapid Delves method. Therefore, a study was conducted by AIHL to determine the equivalency of the two methods, cf. AIHL Report 161, Appendix, The results demonstrated the Delves ratio method, when adjusted by the appropriate proportionality factor, to be equivalent to MIBK, the reference method. The MIBK method was used for the analysis of foodstuffs including market samples, garden vegetables, and hospital diets (AIHL Method No. 42, Appendix). Air samples collected on cellulose paper were analyzed by an atomic absorption method following acid digestion of the filters (AIHL Method No. 41, Appendix). ' " > 2. Aminolevulinic Acid Dehydratase (ALAD) in Blood a) Method Blood was analyzed for ALAD by the method of Bonsignore et al(^). The method is based on the formation of po rph obilino gen (PBG) from 5`"aminolevulinic acid under the influence of ALAD in blood. The resulting PBG reacts with p-dimethylamino-benzaldehyde to form a red color which is read spectrophotometrically at 553 nm. b) ALAD Stability Study Because of questions concerning stability of ALAD, only those blood samples collected in northern California were analyzed for ALAD. In a concurrent study it was established that blood specimens for ALAD determination should be analyzed within 10 hours after drawing the blood. The enzyme activity is best determined within 4 hours of drawing the blood. When the analysis cannot be done in this period, it is possible to* -15* DUP040008529 correct the results for the decrease in activity. The results from the stability study are described in a paper by Prpic-Majic, et al, Appendix. We adjusted ALAD results as described in the article. 3. S-Amlnolevulinic Acid (ALA) in Urine The method used is based on condensing ALA with acetylacetone to form a pyrrole which in turn reacts with p-dimethylamino-benzaldehyde to form a red color. The method was modified to permit the use of disposable ion-exchange columns. The method is des cribed in AIHL Method No. 20, Appendix. v Interlaboratory Comparis ons For blood and air samples obtained in Alpine County, samples were split between the AIHL and The Kettering Laboratory of the University of Cincinatti School of Medicine. For air samples, excellent agreement was observed. For blood samples, the Cincinatti readings were nearly always higher than Berkeley. (See Figure 1.) There is a correlation of 0.57 for males (N = 17) and 0.47 (N 19) for females. There is a peculiar distribution of values as well, suggesting a constant excess of about 5 pg/lOOg in Cincinatti, for values less than 15 ug Assuming that these differences are constant and that the true values lie between the Berkeley and Cincinatti results, Berkeley reports may underestimate lead in blood and Cincinatti may overestimate it. -16- \ DUP040008530 40 r~ 30 Figure I BLOOD LEAD CONCENTRATION ALPINE COUNTY SPECIMENS . INTERLABORATORY COMPARISON Males o Females r = 0.6098 rrl Si p s eJi 20 &* o 10 o o m o oo o 0*0 o oo 'I oo * 0I 10 20 30 40 Blood Lead in ng/lOOg Cincinnati Males Mean S.E. N r Berkeley (CSDPH) Cincinnati (Kettering) 15.65 v 1.475 17 0.573 20.65 1.043 Females Mean S.E. N r 11.42 1.044 19 0.465 36.16 0.866 Both Sexes Mean Cincinnati Mean Berkeley 1.362 -17- DUP040008531 REFERENCES 1* YEAGER DW, CHOLAK J, HENDERSON EW: Determination of lead in biological and related material by atomic absorption spectrophotometry. Env Sci Tech 5:10, p. 1020-1022, October 1971 2. DELVES HT: A micro-sampling method for 'the rapid determination of lead in blood by atomic-absorption spectrophotometry. Analyst 95, p. 431-438, May 1970 3. FERNANDEZ FJ, KAHN HL: The determination of lead in whole blood by atomic absorption spectrophotometry with the "Delves. Sampling Cup" technique. Atomic Absorption Newsletter 10:1, p. 1-5, January-February 1971 : ' 4. B0NSIGN0RE D, CALISSANO P, CARTESEGNA C: Simple method for the determi nation of ALAD in blood. Med Lavoro 56:199, 1965 -18- % r:>. DUP040008532 IV. CHOICE OF COMMUNITIES The choice of communities to be studied was motivated by the basic plan of the study, which was to obtain both environmental and health data from areas which would represent exposure of human populations to several different levels of lead in the ambient air. Benicia and Crockett were chosen to represent relatively high exposure in northern California, partly because of the relatively high exposure to lead suggested by the hiy.ii levels oti lead found in vegetation (Avena) sampled in the area, and partly as a result of the concern for the effects on human health of the exposure through the food chain which was believed to be a cause of the horse'deaths in the Benicia area. In early discussions of possible choices for an area of low exposure in California, Alpine County was suggested because it had previously been shown to yield relatively low levels of lead in blood and urine obtained from residents. However, it was proposed that a more urban coastal area might be more suitable in terms of selecting a population whose other characteristics (relevant to exposure to lead from other sources) would be more nearly comparable- to those of the Benicia-Crockett area. The Bodega Bay and Fort Bragg areas were proposed as candidates. However, it was subsequently learned that the Kettering laboratory was planning a study which would involve obtaining blood specimens from residents of Alpine County during a health fair and that ambient air sampling would also be carried out. It was therefore decided to enter into a cooperative arrangement to obtain blood, urine, and questionnaire data from participants in the health fair. The obvious choices of areas in southern California were an area near the coast to represent low exposure and an inland area to represent high ex posure; Again, areas were Sought which would yield populations whose exposure to lead from sources other than the ambient air would not be drastically different. Pasadena was tentatively selected as the high exposure area, but upon inspection, was rejected for the following reasons: 1) Much of the downtown area was being converted from older single-dwelling units to newer multiple dwelling units,' which 'suggested that relatively few residents would meet the minimum residence requirement of three years (discussed below) as well as that they might represent significant demographic differences from occupants of single dwelling units, 2) some residential areas near the downtown area were being demolished for freeway construction, 3) the southern area of the town (toward San Marino) represented an obviously high income level, 4) the northern end of town (Altadena) was at a higher elevation and would probably not have represented as high an exposure to air pollution. Burbank appeared to offer a more stable, typical area with high exposure to air pollution. Coastal areas in Santa Monica, Venice, and Playa del Rey were considered, but these either represented high income levels or beach areas with shoddy DUP040008533 housing which suggested low income levels and populations with unstable residence* Manhattan Beach was selected as a better possibility, but an area of the city slightly inland was selected as being somewhat more com parable to the Burbank area than that near the coast. ,-20- ' '3 DUP040008534 V. SAMPLING AND COLLECTION OF HUMAN SPECIMENS Adults Sampling in Burbank and Manhattan Beach was carried out in relatively homogeneous (as suggested by inspection of housing), compact areas several square miles in size. Households were counted and the sampling ratio was calculated to give the number of households needed for initial screening interviews in order to obtain approximately 50 eligible adults who Would satisfy the screening requirements and from whom blood and urine specimens could be obtained. Using the sampling ratio, a systematic sample of house holds was selected using a random start. Similar sampling methods were used in Crockett and Benicia, except that sampling was carried out in the entire community in each case, with the exception of a new area in Benicia In which length of residence was uni formly less than the required three years. It was necessary to augment the original samples in Benicia and Crockett in order to obtain an adequate number of subjects who passed the screening test and agreed to give blood and urine specimens. The screening questionnaire was completed by personal interview, and con sisted of several parts. The first page was used to determine whether the respondent was the appropriate person in the household to be solicited for the study, that is, an adult male or female, the sex having been randomly designated ahead of time. If an adult of the required sex was not living in the household, any adult living there was accepted as a candidate for the study. If the initial respondent was not the appropriate person, an appoint ment for later interview was made. The candidate was then questioned whether he had lived within the study area for less than three years, had worked in any one of several occupations designated as high risk for exposure to lead, or had ever been treated for lead poisoning. A positive answer to any of these three' questions immediately disqualified the candidate for inclusion in the study. If the candidate passed these screening questions, he was then asked questions concerning commuting habits, medical conditions, smoking, past or present employment in some occupations not considered high risk but with the possibility of enough exposure to lead so that it should be taken into account in evaluating the laboratory results, and a diet history to determine what foods were commonly eaten in the area and whether any individuals had diets which departed from these in such a way as to be significant in eval uating the laboratory results. A telephone number was obtained for each respondent who passed the screening questions and agreed to donate specimens. Appointments for donation of specimens were made several days before they were collected. In Benicia, collection of the specimens was done in a private physician's office under the specifications of the study, that is, using special leadfree needles, vacuatainers, and urine containers, and with proper handling, storage, and transport of the specimens to the State laboratory. In Crockett, a laboratory technologist visited the homes fo participants to obtain specimens. In both Benicia and Crockett, specimens were delivered to the laboratory and held -21- n DUP040008535 for a maximum of 12 hours before determination of ALAD was carried out, then both blood and urine specimens were frozen for subsequent determination of lead concentration and, in the case of urine, ALA determination. In Manhattan Beach and Burbank, no attempt was made to deliver the specimens to the laboratory within the time limit necessary for ALAD determination, but they were frozen for transport to the laboratory for subsequent determination of lead concentration and ALA analysis. In Alpine County, refrigerated specimens were transported to the laboratory during the night following the Health Fair. School Children Selection of school children for participation in the surveys was done through the school districts serving the areas covered by the survey of adults. The judgment of each district was followed as to which third grade classes would be most suitable for inclusion in the study based on probable cooperation of children, parents, and school personnel. Class rosters were supplied, and a systematic selection of panels of children for each area was made. Parents of these children were contacted directly by the study staff in Benicia and Crockett (by mail) and through the schools in Burbank and Manhattan Beach. In Benicia, appointments. Were made for specimens to be obtained in a pri vate physician's office; in Crockett, an evening clinic was held at the local community center; and in Burbank and Manhattan Beach, clinics were held at the schools with the participation of school personnel and parent volunteers. Blood and urine specimens were obtained in Benicia and Crockett, and ALAD determinations were carried out in addition to lead concentration and ALA determinations. Only blood specimens were obtained in Burbank and Manhattan Beach because of the difficulty that had been experienced in obtaining adequate urine specimens from children in northern California, and the blood specimens were not analyzed for ALAD because of the difficulty in delivering them to the Berkeley laboratories whthin the crucial time limit. Children were also screened for length of residence and previous treatment of lead poisoning. Table 1 shows the numbers of adult respondents originally contacted, the numbers who did not pass the screening criteria for various reasons, and the numbers of specimens finally obtained. The method of sampling adults from the general population was selected in the hope of obtaining broad representation of the area being studied and of obtaining samples unbiased with respect to relevant factors other than air pollution exposure, such as diet. However, because of the high rate of failure to meet the screening requirements, the high rate of refusal to give blood specimens, and the failure to keep clinic appointments, it Is doubtful whether a "better" sample was obtained than would have resulted from the less expensive method of using individual volunteers or volunteers from organized community groups. It is unlikely that significant bias would occur from such volunteers unless special conditions of water supply or diet were encountered, and these could be screened by questionnaire. > \t DUP040008536 Table 1 HOUSEHOLD SAMPLES AND SUCCESSFUL CONTACTS HOUSEHOLD SAMPLE Number of Housing Units Vacant housing units Unable to locate occupant Contacts made Refused interview Screening criter*ia not met Less than 3 yrs. residence Occupational exposure to lead Past lead poisoning Interviews completed No specimens collected Specimens collected BENICIA CROCKETT 194 160 84 90 177 156 13 17 75 38 55 26 20 12 00 89 , 101 37 50 52 51 MANHATTAN BEACH 205 1 10 194 23 41 24 17 0 130 89 41 BURBANK 201 5 31 165 25 24 19 5 0 116 73 43 -23- ^...- 01^040008537,^^ 1 VI, POPULATION SAMPLING RESULTS r A, Raw Data Laboratory results for Individuals who participated in the study are given in the Appendix. B, Analysis and Interpretation 1. Distributional Attributes The departure of the distributions of results for the various te$ts from normality does not appear to be marked enough to invalidate the use of normal theory in performing statistical tests of sig nificance* 2. Proportion Outside of Provisional Limits : Of the entire population sample, only two adults had blood, lead f3**"' concentrations greater than the acceptable"'Trid-jyldnal upper limit l l of 40 mk /100 ml recommended at the Amsterdam symposium. Both of jV' ; fhese were male residents of Crockett. No children had values above the recommended upper limit of 35 ug/100 ml of blood lead. | The concentrations reported by our laboratory as pg/100 g have been accepted as roughly equivalent to those proposed at Amsterdam as pg/100 ml. In fact, a better approximation to the Amsterdam units would result from multiplying the California values by a r' conversion factor of about 1.05. Methodological differences could also result in lack of comparability of our data with the Amsterdam . recommendations. Unfortunately, it is not possible to compare A1AD and d-ALA values from this study with the recommended standards proposed at the Amsterdam conference because they are reported in different units than ours , and the methods-used for both these determinations are not specified. However, the blood lead values as reported above are probably roughly comparable. 3. Comparisons by Area Comparison of mean values by area for blood lead, ALAD units, urine lead, and d-ALA are shown for adults and children respec tively in Tables 2 and 3. Significance tests were done for each of these measurements for the differences between Benicia and Crockett, and the differences between Burbank and Manhattan Beach. In adults, statistically significant differences between mean values in Benicia and Crockett were found for blood lead for both males and females (Crockett higher than Benicia), and for ALAD units for males (Benicia higher than Crockett). Differences between Burbank and Manhattan Beach were not significant among adults. In children, statistically significant differences for both males and females were found between mean blood lead levels in Burbank and Manhattan Beach. For both adults and children, ALAD unit determinations were done L only for Benicia and Crockett because of the critical timing of the -24- w DUP040008538 laboratory test. Urine lead and d-ALA determinations were not done in Burbank and Manhattan Beach because of the difficulty in obtaining adequate specimens from children and the problem of freezing and transporting specimens to the Berkeley laboratory. Comparisons Among Tests In terms of the presence or absence of statistical significance in mean area differences, the following can be said. a. Of the four area differences for which both blood ALAD units and blood lead concentrations were available, both, tests gave y the same results except for adult females. That is, both tests showed significant area differences between Benicia and Crockett among adult males, neither showed significant differences between Benicia and Crockett among children of either sex. Adult females showed a significant difference in blood lead only. b. Of the six area differences for which both urine lead concen trations and urine d-ALA measurements were available, both gave consistent results except for adult males in Benicia and Crockett, for whom only lead concentration differences were significant, and for adult females, for whom only d-ALA differences were significant. c. Comparisons of significance tests for blood and urine results also show some inconsistencies. For the groups in which significant area differences did occur for blood lead and ALAD units (Benicia and Crockett adults), significant area urine lead concentration differences occurred only among males, and significant d-ALA differences occurred only among females. Significant area urine differences did not occur in any groups not showing blood lead or ALAD differences. % " These results are shown in Tables 2 and 3. No evaluation has been done of the relationships between the results of the various tests in individuals. V -25- DUP040008539 Note: Signicance tests refer to differences between means for Benicia-Crockett and Burbank-M anhattan Beach. (N o) i H ert r* ,x3 *& 5 s O' <0 r- do o>- <o <<< 2Z Z os o- co --4 d IS CO --< o Cft 1ot-/4. u o .S Ou 3 ert. :j s jo c m o oo 04 <n OJ *-* o n in 64 in <-< -<t o cO *-* NO IN in 1-h CM --< m in r< q 001 T" T**4 oi cO 04 in oi <<< ,2Z2 VOO NcOo NO o ^ NT o i oi << < 22 Z <<< 222 -<r 64 Os. CM -O no q r~* *4 d co oco a-oj: 4 *-4 O rO<n ion* Tf Ol NO 1-4 --4 i--4 O 04 CO CO 64 - M r< c m --4 ^0 o0 co CO 04 04 O co d 04 O NO co q md in <o 04 nod 04 O NO 04 m is 001 0d4 co |S v) ov c *E. <<< zzz m oi in O --4 fN 04 6* 04 0-. qq no d o' oi o << < 22 Z >i~o4.T0j4" s o* # o-rf i0n4 d 04 d 04 ct--mt qo no d 04 Nf ON fS: S- r-4 tO oi q od 04 NO 04 i--i o odd 04 vO 04 *-4 o no d 04 0~ CO 04 odd oo o oo to > *4 < 2 < o se s euCQ- o oi -2 25 yy 3 ii-nK *5 D a -< < t2u : e ui 22w -o -1 i> C; 5 2 >*. co 2 ui Z 2 <n >4 < 1 Q 2 Vm c SW 22 id m 1-4 -c oo <g<g *S'c m n OV I* Im r ctf 1 VI S5 Vu ec U 4> O 'U 55 -Ort ra Q Ct ,o Z z< -26- DUP040008540 C rockett 13.80 1.53 100.50 11.36 3.13 0 .3 3 Note: Significance test refer to differences between means for Benicia--Crockett, and Burbank -Manhattan Beach. cn CM 1 <n v 3 H B <1 * BS s Jd cCTJ 9 J3 t. < 3 . n* in o o. O O' IN- rH t~- fN vq Or-H' oC-J' O of--f <z. <z Cz z<<z z< o 1--4 <z <z z< <z <z <z NO <<< Z.Z Z z< z< <z o cn cn o o1-4 dd .aO e o C S1 -c f} <u 2 e>i r-4 VO ^d 1--4 t--4 00 CO CO vO jd ccS CA OS w -oU. 3 CM r^* <n i-4 CM < 2 <u u Ow \A C* a cn ON cn oo CO Tf CM rr 1--4 nO & f> rd d 1--4 1-4 - 60 o o 00 N 00 > a < 2 JKQt ^<3u** >4 2c 3 < ~d Oo Z 2' Q < 3< o cn <0 cn NO 1--4 i--4 r--4 NQ 1--4 m cn c m CM O 1-4 CM cn o o <<< 222 <<< ZZZ <<< Z Z Z. <<< 2 2 -2 fH (NJ NO NO 00't<> 1--4 O' O CM in *ict t J- n o d *--4 i--* >V <z <z <z -4- r- c j cn; -4- c4 o' O CM C< CM OS CM d --4 <z <z <z --! CM <n o <x> o o cn "Mcn o o c> o CM ert- 4) 2 2 ui Z 2. "Sh 3 -a O C 4) o o i--4 24) 1* 2 41 W 2 cd < *4 c SZ- m. 2 2 co C>D V <y crOt eg d00 Crt a>a c<u +- -o t<U/D> c<t> -7Or3t >ctf a wO 2 < 2 -27- DUP040008541 VII. ENVIRONMENTAL SAMPLING RESULTS Raw Data 1. Food Chain Hazards Results of determination of lead concentration in a large variety of foodstuffs are given in the Appendix, These are in the form of three lists arranged in the following ways: y a. Ascending order of food code number within each area, to facilitate comparisons of specific foods. b. Ascending order of food code number within area within food type (vegetables, meat, fruit, fish, beverages, dairy products, ' bakery products, and miscellaneous). c. Descending order of lead concentration within area, regardless of food type. At the end of each list the hospital diet and backyard garden data are shown. 2. Air Monitoring Lists of the air monitoring data by day and location are appended. 3. Data for Lead Concentration in Avena Collected from Manhattan Beach Analysis and Interpretation * 1. Food fchain Hazards Food intake was sampled by purchasing common food items from local grocery stores and by obtaining samples of food grown in backyard gardens in each area. Results of interviews were used to determine whether diets differed appreciably in the different locations and to determine which grocery stores were used most frequently. Com parable items of food could not be obtained consistently in all areas because of differences in seasonal or local availability and problems of transportation and storage. Lead concentrations in some common food items obtained from most areas are shown in the summary tables (Tables 4 - 6), and no consistent area differences can be detected. When more than one sample was obtained from an area, values for each sample are shown. Considerable variation occurred between different food items as well as between different samples of the same food. The highest concentration of lead occurred in carrot greens from a backyard garden in Benicia (5.60 hg'/g) . Other vegetables with high values were chard, parsley, lettuce, mustard greens, and spinach, with concentrations ranging from 0,85 - 2,41 Mg/g. Other foods showing relatively high concentrations of lead were anchovies and anchovy paste, veal kidney, top round, tuna, and ham, with values ranging from 0.84 to 2.00 Mg/g. DUP040008S42 The Bureau of Radiological Health routinely collects samples of hospital diets for surveillance of background radiation,, Each sample consists of all food and beverages from a hospital tray as it is served to patients, including all liquids * Twenty*-four samples from throughout the State were analyzed for lead concen tration. The values were uniformly low and range from <53.01 Pg/g to 0,17, all but three of the values being less than 0.10, Individual values appear in the computer output of food lead levels. No evidence was found that a significant amount of lead would be Ingested through the food chain, nor were significant area differences detected. -29* % , DUP040008543 Tabic 4 COMPARISON OF LEAD CONCENTRATIONS IN FOOD BY AREA (pg/g for individual samples) FRUIT Apples Tomatoes Oranges VEGETABLES Lettuce Parsley Spinach Romaine Celery Eggplant Carrots Potatoes ALPINE .15 . .20 .02 .18 NA .05 .20 .32 .26 .04 .02 .31 .12 .02 ,04 BENICIA ,09 .09 .02 < ,01 .12 .08 NA .66 .88 .23 .09 ,40 NA .05 .05 .12 .10 .09 .13 CROCKETT < .01 <.01 .06 .08 .54 .24 .85 .08 V .00. .02 <-01 .02 BURBANK .08 .03 .03 .06 .04 ,07 ,06 .02 .04 .10 ,05 ,04 . .04 .26 . 1.25 .69 .35 .05 NA .03 .05 .05 .03 MANHATTAN BEACH .05 .05 .02 .05 .10 ,49 .42 .15 .12 .03 .17 .05 NA: Not available. -30- \ DUP04000B544 Tabic 5 COMPARISON OF LEAD CONCENTRATIONS IN FOOD BY AREA (Ug/g for individual samples) MEAT Ground Beef ALPINE BENICIA .16 < .03 Chicken .16 <.03 .42 .16 Bacon .30 .20 .06 .44 Ham .84 ' .13 .08 .32 Lamb Chops .10 .18 .16 <.03 Pork Chops .16 .27 .19 .38 <.03 DAIRY Butter .12 .45 .17 Milk <.01 .08 .03 .06 Eggs .02 .12 .04 Cottage Cheese NA .06 GRAIN PRODUCTS Bread .18 .83 .63 Margarine -- ~-- . . .. .52 NAs Not available. x2 ; Two samples each. .08 .13 CROCKETT .12 .10 ' .28 .22 .17 .15 .05 .06 .08 .08 NA NA BURBANK .08(x2) .09 (x2) .10 .03 .11 .08 .10 .09 .07 .05 .15 .10 .06 MANHATTAN BEACH .07 y ' .09 .24 .16 .25 .07 .05 .03 i07 .04 .13 .06 DUP040008545 Table 6 COMPARISON OF LEAD CONCENTRATIONS r IN BACKYARD GARDEN PRODUCE BY AREA (ptg/g for individual samples) Apples Carrots Zucchini Chard Lettuce Bell Peppers Tomatoes Cherry Tomatoes Figs Lemons Strawberries BENICIA AND CROCKETT NA .47 .16 .18 .19 .07 .05 < .04 .15 .29 2.41 NA .08 .03 .18 .05 <.09 .08 .01 .07 .06 ;12 NA .29 .09 .26 .21 .14 .47 BURBANK .24 .23 ,30 ,06 .02 .30 .70 .10 .04 ,04 .18 .09 .08 .08 ,06 NA NA: Not available. -32- MANHATTAN BEACH .07 .07 .02 .57 .42 .02 .02 .04 .03 .16 .06 .45 DUP040008546 Air Monitoring Table 7 shows a summary of the air monitoring data. High volume sampling stations were set up within each of the residential areas studied. The mean lead concentrations by quarter for Burbank are consistently higher than the comparable means for Manhattan Beach, but only the differences for the Second quarter of 1972 are statistically significant using a two-tailed t-test (p <0.05). The differences between means for Benicia and Crockett are not consistent in direction, and the only statistically signi ficant difference using a two-tailed t-test is for the third quarter of 1972 (p <0.1). The consistently higher mean values in Burbank when compared to Manhattan Beach suggest that these differences could be a factor in the higher blood lead concentrations found among Burbank children. This is supported by comparisons of the values for individual days, which also show a marked tendency for Burbank values to be higher than those reported from Manhattan Beach. Results of sign tests were significant at the 5% level for the first and second quarters (6 out of 6, and 9 out of 10 differences, respectively, showing higher values for Burbank than for Manhattan Beach) while a similar test for all three quarters combined was significant at the 1% level (31 out of 41 differences showing higher values for Burb ank). The significantly higher mean value in Crockett when compared to Benicia (second quarter, 1972) corresponds to the significantly higher blood lead means found among adults in Crockett. However, the relative lack of consistency in direction of differences for Individual days, as well as the uniformly low vaxuas, suggesfs ~the lack of a significant human effect, at least from Inhaled air. The possibility of air exposure to lead on soil and vegetation is a different problem. . ' J '' Avena Sampling ' Avena sampling in Benicia and Crockett and subsequent analysis for lead has been carried out and reported under a previous interagency agreement with ARB. It was planned that Avena be used in this study as a supplemental method of indicating exposure to airborne lead. However, Avena was not generally available in the Alpine County study area nor in the Burbank area. Several Avena samples were collected in the Manhattan Beach area. The results of these analyses are given in the Appendix. -33- DUP040008547 TABLE 7 Summary of Air Sampling Data Mg/m3 s Time Interval Burbank N Mean S.E. Fourth Quarter, 1971 10/8 -11/7 25 2.315 0,312 First Quarter, 1972 1/12 - 1/30 13 5,458 0.684 Second Quarter, 1972* 4/4 - 4&23 10 3.267 0.502 Manhattan Beach N Mean S.E. 25 1,979 0.253 13 3.658 0,569 10 1.868 0.432 Time Interval Benicia N Mean S.E. First Quarter, 1972 2/7 - 3/23 8 0,741 0.211 Second Quarter, 1972 3/30 - 6/29 9 0.211 0.052 Third Quarter, 1972** 7/5 - 9/27 14 0.195 0.018 Fourth Quarter, 1972 10/3 - 12/26 10 0.328 0.049 Crockett N Mean S.E. 8 0.598 0.140 11 0.317 0.088 15 0.303 0.033 10 0.250 0.040 * Difference between means significant at 57, level, two-tailed t-test. ** Difference between means significant at 1% level, two-tailed t-test. 34- DUP040008548 r f':; VIII, SUPPLEMENTARY STUDIES OF CHILDREN A. Six-Community Study in Los Angeles The six community study in Los Angeles was designed to compare the effects of air pollution on lung function and other indicators in communities representing high, moderate, and low exposure. Two communities were chosen to represent each exposure level. Results reported here are limited to blood lead concentrations in elementary school boys and girls, mostly 9-10 years old, and in male high school athletes (Table 8). In most cases, male-female differences among the elementary school children were slight, although males showed consistently higher concentrations than females. No consistent differences were observed between elementary school children and higi school students. The lowest mean concentrations of lead occurred in the two low pollution communities for both elementary and high school students, but the highest mean value in elementary school students occurred in an area of moderate pollution. Means from the two high pollution areas combined (Riverside and Azusa) and the two low pollution areas combined (Lancaster and Oceanside) were tested for each sex for statistically significant differences. Both high School and elementary school differences were significant at the 5% level. B. Housing in San Diego Population samples of preschool children were chosen in several areas of San Diego County representing pre-World War II housing containing lead-based paint. These included east San Diego, representing whites with non-spanish surnames and "other" than low economic status; south east .San Diego, representing low economic'status and a variety of ethnic backgrounds; National City, representing low economic status and with all but two Individuals in the sample having Spanish surnames; Pala, an Indian reservation; Escondido, with a sample consisting entirely of in dividuals with Spanish surnames; and Oceanside and Carlsbad represented by one child each. East San Diego, southeast San Diego, and National City were each repre sented by children who could be classified as living near traffic or away from traffic. Boundaries between "near" and "away from" traffic were set to coincide with divisions between city blocks. "Near" was within 380 fee of traffic; "away from" was between 380 and 700 feet, Differences be tween mean blood lead concentrations In the groups living near and away from traffic were tested separately for each of these three areas and for all three areas combined using a two-tailed t-test. The only statistically significant difference was for National City (p <0.05). These results, along with mean values for other areas, are shown in Table 9. There were no mean values or individual values that exceeded the suggested limits from the Amsterdam Symposium. -35- DUP040008549 9 Lead concentrations in soil ranged, from 45 ppm to 2256 ppm. A rank correlation test (Spearman's rho) was used to determine whether there existed a significant correlation between blood lead concentration and concentration of lead in soil from corresponding play areas, either within any of the study areas or for all areas combined. The results were not statistically significant at the 5% level. For all areas combined, a median test was done to determine whether significant differences in soil lead concentration occurred between samples collected from households near traffic compared with those away from traffic. These results, also, were hot statistically significant at the 5% level. % -36- DUP040008550 i r Tabic 8 BLOOD LEAD CONCENTRATION Qug/l 00 g) BY LOCATION AND SEX SIX-COMMUNITY STUDY OF SCHOOLCHILDREN SOUTHERN CALIFORNIA POPULATION Elementary School Male N Median Mean S.E. of Mean Female N Median Mean S.E. of Mean High School `Male N Median Mean S.E. of Mean HIGH POLLUTION Riverside Azusa MODERATE POLLUTION Long Beach Culver City LOW POLLUTION Lancaster Oceanside 27 ` 18 22 28 10 n.o 11.0 11.0 ' 14.0 8.0 12.1 12.6 11.4 14.6 . 9.2 0.6 0.7 0.6 0.8 i.o - 24 10.5 10.8 0.5 23 23 24 21 28 11.0 12.0 10.0 12.0 8.0 11.4 12.0 10.7 12.4 8.5 0.5 0.7 0.6 0.6 0.4 19 9.0 9.8 0.5 17 23 30' 19 20 11.0 14.0 12.0 13.0 9.0 12.1 14.6 12,6 14.0 9.0 1,0 0.6 0.5 0.6 0.5 26 9.5 10.1 0.6 Note: Differences between pooled means for the high and low pollution areas were statistically significant at the 1% level for both high school and elementary school differences. V- -37, r DUP040008551 TABLE 9 d iffe r e n c e between means s t a t is t ic a lly s ig n ific a n t (p < 0 .0 5 , tw o -ta ile d t - t e s t ) . -Of M a CD A oH O H* rt Oa A ss co M toCU so 6 H- rr C oA. H* rt rr O rr p* 3 to &> 0a So rb M CO Q rr O H* rt cn H* (0 fD 3 OQ O > H tPo os 3 mno> IO u? to *o Ui 4> o 4> o 1-* M - *-* *-* N> .JP* Ui Ln . to IO to ON so H * fO M o O' O vO O SO oo Ul bo to CO CO to >o M to Cn 4s> >o 00 ON h-* to H t- H* C-* to * Os Ul N> tO . to JN to * H* to M H* H* * SO O M :4> o 00 to M SO ON U> 55 rt IT o 0a5 rt a rt CO w J| 2! > a? &> S K HI a a rt Q 0 H3 na CO Hi rHti wo OTSQ. wOMO l-- to 4> 1 i U> CO to 00 --* M H-* CTv P* ON 1 i * .* O Ul 4> CO X- 1 t H* oo ,* co o 00 ON Ua vO u> CO 85 85 a 0a H 2! R> rt a a n a Hi Hi H* O CO w DUP040008552