Document mqGQrM5Zyqxpr6E3nM8MKR9VZ

w FINAL REPORT Lead Paint Ingestion Study by Midwest Research Institute 425 Volker Boulevard Kansas City, Missouri 64110 Contract No. 62-W-62GC&NPC MRI Project No. 3729-B Under a Grant from: National Paint and Coatings Association, Inc. 1300 Rhode Island Avenue, N.W. Washington, D. C. 20003 n ca oo 012;: FINAL REPORT Lead Paint Ingestion Study Midwest Research Institute 425 Volker Boulevard Kansas City, Missouri 64110 MRI$ National Paint and Coatings Association, Inc. 1500 Rhode Island Avenue, N.W. Washington, D. C. 20005 ooo r\po Preface This report was prepared at Midwest Research Institute, 425 Volker Boulevard, Kansas City, Missouri 64110 under Contract No. 62-W-62GC & NPC. MRI Project No. 3729-B, "Lead Paint Ingestion Study." The Research was sponsored by the National Paint and Coatings Association, Inc., (NPCA ), 1500 Rhode Island A venue, N. W., Washington, D. C. 20005. Royal A. Brown, Technical Director, National Paint and Coatings Association, Inc., was the project monitor. The research was conducted in the Bio logical Sciences Division, under the direction of Dr. W. B. House from I December 1972 through 31 July 1973. Dr. Thomas R. Castles, Principal Pharmacologist, was the principal investigator, assisted by Dr. Jaime Sanyer, Associate Pathologist, and Mrs. Jane Hoch, Biology Research Assistant. Dr. James L. Spigarelli, Senior Chemist, supervised the lead analysis with the assistance of Mrs. Hope M. Miller, Assistant Chemist. Members of the National Paint and Coatings Association Industrial Metals Task Force prepared the paint chips and consulted with Drs. Castles, Sanyer, Spigarelli and House during the course of the study. The personnel of the NPCA Industrial Metals Task Force is as follows: Richard A. Moore The Shenvin- Williams Company'--Chairman Royal A. Brown The National Paint and Coatings Association, Inc. John P. Frawley Hercules, Inc. Charles M. Jackson Celanese Coatings <& Specialties Co. Joseph G. Kingston Glidden-Durkee Division of SCM Corporation Sidney Lauren Coatings Research Group, Inc. William W. Ringle Pratt & Lambert, Inc. Edwin E. Swain E. /. duPont de Nemours & Co., Inc. Jean P. Teas The Flood Company Domenic J. Tessari De Soto, Inc. Approved for: MIDWEST RESEARCH INSTITUTE W. B. House, Director Biological Sciences Division 25 February, 1974 Table of Contents Pag* I. Introduction ................................................................................ i II. Methods ...................................................................................... 1 A. Preparation of Paint Films Containing Different Concen trations of Lead............................................................ B. Preparation of Diets........................................................ C. Experimental Procedure................................................... D. Analyses............................................................................ E. Pathology.......................................................................... F. Statistical .......................................................................... I 1 1 2 3 4 III. Results ................................................... 4 A. Concentrations of Lead in Paint Films............................ B. Lead Analyses of Diets ContainingDifferent Paint Films C. Preliminary Feeding Studies........................................... D. Gross Observations, Feed Consumption and Body Weights E. Weekly and Total Lead Consumption........................... F. Hematology of Rats Fed Paint Films Containing Differ ent Concentrations of Lead......................................... G. Tissue and Fluid Chemistry of Rats Fed Paint Films Containing Different Concentrations of Lead............ H. Lead Content in Tissues of Rats Fed Paint Films Con taining Different Concentrations ofLead.................... I. Pathology of Rats Fed Paint Films Containing Different Concentrations of Lead................................................ 4 4 4 4 5 10 10 10 33 IV. Discussion..................................................................................... 38 V. Conclusion ................................................................................... 39 References ............................................................................................. 40 I. Introduction Few persons will disagree that the ingestion of old lead-based paint presents a potential health hazard to young children. As a result of reports by Kehoe,1 Chisholm,- and King,3 medical re searchers, paint manufacturers and legislators have recognized the seriousness of this problem and are acting to establish safe concentrations of lead in paint. To do this, they have voluminous reports on clinical observations and animal re search from which to draw. Unfortunately, most of this information is based upon the old white lead paints or soluble lead salts, which are not representative of the paint formulations on today's market. Some studies have been reported 4*5 which indicate that lead compounds are not as readily leached from modern paint films. Before safe concentrations of lead in paint can be intelligently established, we must evaluate the toxicity of the lead as it exists cur rently in modem paints. It was the purpose of this study to evaluate the toxicity in rats pro duced by different concentrations of modem paints containing lead octoate and lead chromate at varying concentrations compared to an old paint formulation containing white lead. The re sults are presented in the following pages. II. Methods A. Preparation of Paint Films Containing Different Concentrations of Lead Paint films without added lead and with added lead compounds in the form of lead octoate, lead chromate, or lead carbonate were supplied by members of the National Paint and Coatings Association. Paints which contained lead octoate, and lead chromate (medium yellow) were pre pared using a fiat aikyd paint formula based upon a Federal Specification TT-R-266D Type I Class B aikyd resin. A white lead in oil paint was prepared from a formula typical of this type paint as it was used in the 1920's. This con tained a high percentage of lead carbonate. The flat aikyd paint without added lead was used for control. The percent of lead in each sample was calculated on the basis of the nonvolatile ma terial. Dispersion was accomplished with a Cowles Dissolver and the pigment volume concentration was held at one level. The paints were placed in pans and allowed to air dry. This was followed by forced air drying at 120F to volatilize any remaining solvent. Paint films were ground and sieved, and chips ranging from 0.5 to 1.0 mm in size were used for this study. This chip size was selected on the basis of a preliminary rat feeding study which established that rats would selectively eat around larger sized chips but would eat chips in the selected size range. The concentrations of lead in the dif ferent paint films were determined independently by De Soto, Inc., The Sherwin-Williams Company and Midwest Research Institute, using Atomic Absorption Spectrophotometry. A sample of old lead-based paint col lected from walls of old dwellings was obtained from the U. S. Department of Commerce, Na tional Bureau of Standards, Washington, D.C. This paint was intended as an analytical standard and had been pulverized and sieved through 325 mesh screen (0.06-0.08 mm size) and contained 11.92% lead by weight as carbonate. This sample will be referred to as "NBS lead paint" in this report. B. Preparation of Diets Diets were prepared by mixing paint chips with Purina Rat Chow mash in the concentration of 0.1% (weight/weight). This was accomplished by first preparing a 10% concentrate (paint film/ feed, w/w) in a high-speed twin shell mixer. This concentrate was then added to the appropriate amount of Purina Rat Chow mash to give a final concentration of 0.1% (paint film/feed, w/w) and mixed for 10 minutes in a bulk mixer. Each diet was prepared three times during the experiment and samples of each of these preparations were assayed for lead content. C. Experimental Procedure Two hundred weanling (40-60 gm) Charles River rats (100 males and 100 female rats) were used for this study. Upon arrival rats were housed individually in air conditioned quarters in poly carbonate cages containing hardwood bedding and filter tops. After 5-7 days of equilibration, all rats were assigned one of the following diets: 1. Rat chow plus paint chips without added lead (control) 2. Rat chow plus paint chips containing 0.08% lead as lead octoate 1 3. Rat chow plus paint chips containing 0.33% lead as lead octoate 4. Rat chow plus paint chips containing 2.03% lead as lead octoate 3. Rat chow plus paint chips containing 0.42% lead as lead chromate 6. Rat chow plus paint chips containing 1.93% lead as lead chromate 7. Rat chow plus paint chips containing 12.43% lead as lead chromate 8. Rat chow plus paint chips containing 66.03% lead as lead carbonate 9. Rat chow plus NBS lead paint contain ing 11.92% lead as carbonate Twenty male and 20 female rats were assigned to the control diet, and 10 males and 10 female rats were assigned to each of the remaining diets. Each diet was fed in a 9-oz wide-mouth glass jar which was secured to the cage. Tap water was available ad libitum during the entire experiment. Feed consumption was measured twice each week and calculated on a daily basis. The animals were weighed once a week. All rats were observed twice or more each week for toxic signs. After 4, 8 and 13 weeks, a selected number of male and female rats from each group were placed in metabolism cages for the collection of 24-hr. urine samples. A portion of the col lected urine was used for urinalysis and the re mainder frozen for assay of delta-aminolevulinic acid and coproporphyrin. After urine collection each rat was anesthesized with ether, exsangui nated via the abdominal aorta and bone marrow smears were prepared. Blood samples were hep arinized, cooled and used immediately for hema tology and enzyme assays. Aliquots of the re maining blood were taken for protoporphyrin and lead assays. After urine and blood samples were obtained, each rat was necropsied and tissue taken for lead analysis or microscopic examina tion. D. Analyses 7. Lead analyses of paint chips and diets con taining paint chips: a. Paint film: Ten-miligram samples of paint chips containing no lead or 0.08% lead octoate were charred with 3 mi of con centrated nitric acid and dry-ashed at 300 C for 2 hr. The ash was dissolved in 1 ml of aqua regia, diluted to 5 ml 2 with distilled water and this final dilution measured for lead content by atomic ab sorption. All other paint chips (10 mg samples) were digested in 15 ml of a mixture of concentrated nitric acid and 37% perchlo ric acid (2:1, V/V), evaporated and the remaining perchloric acid solution diluted to 25 ml with distilled water. This final dilution was used for atomic absorption spectrophotometry. b. Diets: One-gram samples of feed were di gested in a mixture of concentrated nitric acid and 37% perchloric acid (2:1, V/V) and their final dilutions adjusted to make their lead concentrations within the de tection limits of the atomic absorption technique. 2. Analyses performed upon each rat: a. Hematology: (1) Hematocrit: Hematocrit was deter mined in capillary tubes using a microcapillary centrifuge (Interna tional Equipment Company, Model MB). (2) Hemoglobin: Hemoglobin was meas ured as cyanomethemoglobin.13 (3) Erythrocyte and leukocyte counts: Total erythrocyte and leukocyte were counted using a Coulter Electronic Particle Counter with 100-/4 aper ture.1* (4) Reticulocytes: Reticulocytes were counted by the methylene blue method using the Miller disc.* (5) Differential leukocyte counts: Wright's stain was used to stain the leukocytes for examination. (6) Erythrocyte osmotic fragility: Osmo tic fragility of erythrocytes was quan titatively determined by subjecting heparinized whole blood to sodium chloride solutions of different osmolarities.1 The concentration of sodium chloride which hemoiyzed 50% of the erythrocytes was obtained from a plot of percent hemolysis versus so dium chloride concentration. b. Body fluid and tissue chemistry: (1) Plasma protein electrophoretic patterns: Total plasma protein was de termined using the Hycel Biuret Re agent (Hycel, Inc., Houston, Texas). The quantity of each plasma protein was determined electrophoretically on cellulose acetate and expressed as a percentage of the total plasma pro tein. (2) Erythrocyte-cr-aminolevulinic acid dehydrase (ALAD): <r-Aminolevulinic acid dehydrase activity was deter mined by the method of Lichtman and Feldman.8 This procedure was started 30 min. after each blood sample was taken. (3) Erythrocyte protoporphyrin: Proto porphyrin in erythrocytes was meas ured by the method of Heller, et al* This analysis was performed the day after blood was withdrawn. (4) Urinary cr-aminolevulinic acid (ALA): Urinary cr-aminolevulinic acid was measured according to the Davis and Andelman 10 modification of Mauzerall's and Granick's Method.11 These analyses were performed in subdued light. (5) Urinary coproporphyrin: Urinary co proporphyrins were determined by the method of Schlenker and Kitchell.12 These analyses were per formed in subdued light. c. Urinalysis: (1) Urinary protein (albumin): Urinary protein was measured with "Uristix" reagents strips (Ames Company, Elk hart, Indiana). (2) Microscopic examination of urine: Urine samples were centrifuged, the residues resuspended, and examined microscopically for the presence of erythrocytes and leukocytes under high power field and for casts under low power field. d. Tissue lead: (1) Blood: One milliliter of blood was mixed with 1 mi of a mixture of 5% trichloroacetic acid: 37% perchloric acid (3:1 v/v). The sample was cen trifuged and the supernatant filtered through an AAWP 0.8/4 Millipore filter. The supemate was analyzed for lead with an atomic absorption spectrophotometer using standards prepared in control rat blood. (2) Other tissues: Bone, liver, kidney, and brain were digested in concen trated nitric acid, evaporated to dry ness and reconstituted to the lowest possible volume with 20% nitric acid. These solutions were analyzed for lead by atomic absorption spectro photometry. (3) Atomic absorption analysis: `Lead concentrations were measured using a Varian-Techtron AA-5 atomic ab sorption spectrophotometer. Sample solutions were aspirated into an airacetylene flame and the absorbence was measured at 283.3 nm. Back ground interference was determined with the use of a hydrogen continuum lamp at 283.3 nm and subtracted from the absorbence obtained at 283.3 nm with the Pb hollow cathode lamp. E. Pathology 1. Gross pathology: At necropsy, rats were ex amined for gross abnormalities, their livers, kid neys, spleens, hearts, gonads, thyroids, brains, and adrenals weighed, and the relative organ weights calculated. After weighing, a portion of the liver, kidney and brain were taken for microscopic examination and the rest of each organ was measured for lead content. A femur was removed to be used for the measurement of lead in bone. 2. Microscopic pathology: Bone marrow smears were prepared for myeloid/erythroid cell count. The following tissues were fixed in buffered neu tral 10% formalin: brain, liver, spleen, stomach, small intestine (duodenum, jejunum, ileum), colon, pancreas, kidneys, urinary bladder, adre nals, thymus, gonad, thyroid (with parathyroid attached), mesenteric salivary gland, lymph nodes, heart, lungs, diaphragm, skeletal muscle, and prostate or uterus. 3 V Tissues from ail 13-week rats fed the control, 2.05% lead octoate, 12.43% lead chro mate, 66.05% lead carbonate, and the 11.92% NBS lead paint diets were embedded in paraffin, section to a thickness of 6/*, stained with hema toxylin and eosin and examined for histopathology. F. Statistical Analyses Control and treatment values were compared sta tistically using Dunnett's multipie-comparison test with P<0:05 as the criteria of significance. III. Results A* Concentrations of Lead in Paint Chips The concentrations of lead in the paint chips sup plied by the Members of the National Paint and Coatings Association were analyzed for lead con tent by De Soto, Inc., The Sherwin-Williams Com pany, and Midwest Research Institute (MRI). The results of these analyses are shown in Table 1. The control paint which did not contain lead octoate or chromate was found to contain approx imately 0.01% lead. There was a reasonable agreement between the different analyses, so an average ppm of lead was computed and used for the actual lead concentration of each paint film. Lead concentrations of the lead paint obtained from the National Bureau of Standards were aver aged in a similar manner. B. Lead Analyses of Diets Containing Different Paint Films Table 2 shows the lead content of each diet. Purina Rat Chow mash was found to contain approximately 4^g/gm of lead (assuming 0.1 fig/ gm of lead was contributed by the control paint). The fig of lead/gm of feed which was attributable to each added paint film was reasonably close to its respective theoretical value. The average total fig of lead/gm of feed for each diet was used for the calculation of weekly and total lead consump tion for each rat. C. Preliminary Feeding Studies Before beginning this study, a pilot experiment was performed to see if the rats were consuming the lead paint chips along with their feed. Three rats each were placed on the control diet and the 66.05% lead carbonate diet. After 48 hr., their feces were collected and the lead content meas ured. Feces from rats on the control diet contained 11.5fig of lead/gm feces while feces from rats fed the 66.05% lead carbonate diet contained 3,683 fig Of lead/gm feces. Thus, rats did consume the paint film along with their feed. D. Gross Observations, Feed Consumptions and Body Weights During the entire study only two rats had remark able changes. One female rat on 2.05% lead octo- TABLE 1 Concentration of Lead in Paint Film Paint Film luewcwai ix n <%> Paint Companies <%> Control Paint Lead octoate Lead octoate Lead octoate Lead chromate Lead chromate Lead chromate Lead carbonate NBS lead paint 0 0.06 o.so 2.00 O.SO 2.00 15.00 64.12 -- 0.01 0.08 0.50 1.90 0.42 1.80 12.57 63.20 11.87* Measured by U.S. Department of Commerce. National Bureau of Standards, Washinfton. D.C Average of paint companies and MRI values. Average of Bureau of Standards and MRI values. MRI <%) <0.02 0.07 0.56 2.20 0.41 2.10 12.30 68.90 11.98 Averaft* <%) 0.01 0.08 0.53 2.05 0.42 1.95 12.43 66.05 11.92' 4 TABLE 2 Lead Analyses of Diets Containing Different Paint Films Diet Control paint plus rat chow Lead octoate (0.08%) plus rat chow Lead octoate (0.53%) plus rat chow Lead octoate (2.05%) plus rat chow Lead chromate (0.42%) plus rat chow Lead chromate (1.95%) plus rat chow Lead chromate (12.43%) plus rat chow Lead carbonate (66.05%) plus rat chow NBS lead paint (11.92%) plus rat chow Theoretical * 0.1 0.8 5.3 20.5 4.2 19.5 124.3 660.5 119.2 Theoretical concentration of lead in feed contributed by indicated paint film. Mean *% of lead/gm feed for number of samples shown in parenthesis. Mean m of lead from paint films/gm feed for number of samples shown in parenthesis. Total* 0*g/g) 4.1 (6) 5.2 (6) 12.0 (6) 27.2 (6) 11.0 (6) 23.5 (6) 140.2 (6) 516.0 (5) 124.0 (3) Measured Paint Lead4 (Mg/ga) i.i (6) 7.9 (6) 23.1 (6) 6.9 (6) 19.4 (6) 136.1 (6) 511.9 (5) 119.9 (3) ate developed an abcess on her left shoulder dur ing the ninth treatment week and one female on 66.0S% lead carbonate developed abcessed hind feet in the 10th week and chewed her toes off. The feed consumptions of male and female rats are shown in Figures 1 and 2, respec tively. Each bar represents the mean standard error of six to twenty rats. Except for the rats fed the diet containing 11.92% lead as NBS lead paint, ail groups consumed feed at the same rate as the control group throughout the entire experi ment. The reason the 11.92% NBS lead paint group ate significantly less initially, was that they were started a month after the other rats and were initially smaller. Since this group was con suming feed at the same rate as the control group by 4 weeks, we consider their initial food con sumption normal also (for their size). The body weight gains for each group of rats are shown in Figures 3 and 4. Each bar represents the mean standard error of six to twenty rats. As mentioned above, the rats on the 11.92% NBS lead paint diet were small initially but became similar to controls by either the 4th (females) or 8th week (males). Throughout the entire period the male rats in the other treatment groups gained weight at a normal rate. The female rats did show a change in body weights during the first 8 weeks of feeding which appears related to the concentration of lead octoate. After 4 weeks of feeding, rats in the 2.03% lead octoate group weighed significantly less than control. The pat tern was the same at 8 weeks. After 12 weeks their average body weights still exhibited the same pattern, but the 2.03% lead octoate group was not significantly different from control. This was due to fewer animals and a slight increase in variability. E. Weekly and Total Lead Consumption The weekly and total lead consumption during the experiment was calculated on the basis of the total lead/diet and amount of each diet eaten by each rat. These calculations are shown in Tables 3 and 4. During the 13th week period, the control group consumed approximately 103 ng (males) or 79/ug, (females) of Iead/day, while rats 5 (Xep/iu/<ifl) NOliXWnSNOD 033d < Control Feed Consumption o f Male Rats Fed Different Concentrations of Lead in Paint Chips TREATMENT WEEK o CO TREATMENT WEEK TJ 1l 1 16 6 uV o o HI I] i JU UJ 1111 -4 J -I -J # * a* S 9 S5 * I_____ I_____ I_____ I_____ L n n09 Xn 1____ L-.... J____ I____l O M OB i t t O (Xop/401/146) NOliawnSNOD 0334 7 tfttA fM IN f WUK III] 6 565 5 ?i 8 3 MM N I o' i s sr I I t i (*) IHOHMAOOI J. 8 # o 8 I--------------1------------- 1--------------- 1__________I__________I__________L a s i s? (uia) 1HOI3MAQOJ TREATMENT WEEK 9 eating 2.05% lead octoate, 12.43% lead chro mate, 66.05% lead carbonate, or 11.92% NBS lead paint consumed an average of 787 Mg (males) or 708 /ig (females); 3,591 Mg (males) or 2,689 Mg (females); 13,436 Mg (males) or 9,185 Mg (females); and 3,184 fig (males) or 2,363 Mg (females) of lead/day, respectively. Using the average body weights of rats surviving 13 days, the rats in the control, 2.05% lead octoate, 12.43% lead chromate, 66.05% lead carbonate and the 11.92% NBS lead paint groups consumed 288 Mg (males) or 335 Mg (females) of lead/kg/ day; 2,133 Mg (males) or 3,278 Mg (females) of lead/kg/day; 9,785 Mg (males) or 11,590 Mg (fe males) of lead/kg/day; 37,014 Mg (males) or 42,133 Mg (females) of lead/kg/day; and 9,888 Mg (males) or 10,364 Mg (females) of lead/kg/ day, respectively. F. Hematology of Rats Fed Paint Chips Con taining Different Concentrations of Lead The results of the hematology of rats fed paint films containing different concentrations of lead are shown in Tables 5-13. No differences were observed in the erythrocyte count, reticulocyte count, hematocrit, leukocyte count, differential leukocyte count, and the erythrocyte osmotic fra gility. At 13 weeks, the hematocrits of rats fed the NBS lead paint were significantly lower than control, while the hematocrits of the rats fed the other diets were normal. G. Tissue and Fluid Chemistry of Rats Fed Paint Chips Containing Different Concentrations of Lead Tables 14-22 show the tissue and fluid chemistry of rats fed paint chips containing different con centrations of lead. The serum proteins, erythro cyte protoporphyrin, urinary coproporphyrin, and urinary delta-aminolevulinic acid were not altered by any of the diets. The activity of the erythrocyte enzyme, delta-aminolevulinic add dehydrase (ALAD), in the control, lead octoate (0.08%, 0.53%, and 2.05%) and lead chromate (0.42%, 1.95%, and 12.43%) groups did not differ throughout the experiment (Table 23). ALAD activity was de pressed in rats fed 66.05% lead carbonate and 11.92% NBS lead paint. At 4 weeks (Table 21, 22) there was a depression of 56% and 59% in these two groups, respectively. At 8 weeks the ALAD activity was depressed 44% in the 66.05% lead carbonate group, but the ALAD activity in 10 the NBS lead paint group was not sigificantly different from control. At this time a sex differ ence was observed in both of these groups. The ALAD activity in the male rats remained de pressed at the 4-week levels while the ALAD ac tivities of the female rats returned to control levels. This sex difference may be linked to the fact that these female rats had matured and were probably beginning their menstrual cycles. By 13 weeks the sex difference had dis appeared and the ALAD activity in 66.05% lead carbonate group and the 11.92% NBS lead paint group were depressed 56% and 53%, repectively. Urinalysis of rats fed paint chips con taining different concentrations of lead are shown in Tables 24-32. No marked difference in urinary protein or sediment (erythrocyte, crystals, casts, etc.) were seen in the control, lead octoate, lead chromate and lead carbonate groups. In the NBS lead paint group 5 of 12 rats (42%) had a mod erate proteinuria compared with only 4 of 24 rats (17%) in the control group. Otherwise, the urin alysis of this group was similar to that of the con trol group. H. Lead Content in Tissues of Rats Fed Paint Chips Containing Different Concentrations of Lead Tables 33-37 show the lead content of blood, brain, liver, kidney, and bone from rats fed paint chips containing different concentrations of lead. All values for the lead concentrations in blood at 4 and 8 weeks, and 4 values in all but the NBS lead paint group at 13 weeks were omitted from Table 33 because it was discovered that these samples had been contaminated by their storage containers. The blood lead levels of rats fed paint chips containing lead octoate (0.08%, 0.53%, 2.05%) or lead chromate (0.42%, 1.95%) were no higher than control. In the rats fed paint chips containing 12.43% lead chromate or 66.05% lead carbonate, or the 11.92% NBS lead paint (lead carbonate) blood lead levels were found to be elevated significantly. At 4 weeks, tissue lead levels in brain, liver and kidney were below the detection limits of our assay (0.7 Mg per gm of tissue). The results were the same at 8 weeks with the exception of the NBS lead paint group. All four rats in this group showed detectable lead in their kidneys. V 'O II pm yo *% f"> 00 -W'O^ONNS CM > > nO MJ vO \ \JS . yfl =i "s''3 a'"' w 3 w i=3 ~ S ~ - M` *" *** a' a r a| C|''C!''3''2iea,SKS'5S,ft?lft = 1 *<N=*^-fr^s~ \0s.~^ ^r^r * s*. ia - rf of g 3 3 t 21 3" i ~ i/ w 3 ~ 8 ~ 1~ i w | ~ N m* (S ^P* N 3 CM O CM i g=iwa//s/5Ti/'a~aw (N s < iO VO \0 <0 iO > 3 c m <o c m** n c m" <n c m* CM CM & m s wi -1 -S 0<0 g > aH 1 I1 I s-a-a/a~swiwa~a~i~ >0 -00 OO -00-00 00 l M cm vr> c m* ^ f*C wT i*T c m * c m > OO -00 -00 -oo -00-00 OB 09 I = S'-'i~I~|-S''i~5s! M *" rf v r s a c m^-c m---oo^\--`c**--`m^---c m---*-^ ^ -oo -OO -00 - 00 - 00 - 00 q q OO Ssi''5/i/2/rg'''i~!r N pm P9 pm *f oo* m* 3 V ^ <o ^ >0 oo Q n r*cM~~cMr4M5so IS 5 sC* SsOk SsO^sc^^O^^s io=o2!s Ss S N O* N O* < 1 N c m aK c m & <* "S^o^S^o^o^o^S^o^o s 4 J1?]j* MBOOaD^aO<*a*PMf*> --*m--^flo--*^----- ---'<0---*^--* gg^SgS^S^SgSaSjiS.S -3 a-p:''S''3''!=''S''5wS''2'' -^ ^ a* s' a' !! ii -3 aSsSsSaS g^g.ggg^s -- w^oor<*cM wS cC cT mt * r** o' SJi 3" i V I 3 3S5S3 2 e *gP'5 S? |SSSS s 9 *g15592 1 a If 11 tl ?! mt u o J ti 2c m i.l3oaz =- < < it 12 * Total include* average Pt> intake (17.116.6 ng/ra/w*ek) for weeks 4 and 6 as an estimate for the week 1 intake. TABLE 5 Hematology of Rats Fed Paint Chips Containing No Lead Analyses 4 (N - 8)* Erythrocytes (X lOVrnm1) Reticulocytes, % Hematocrit, vol. % Hemoglobin, gm % Leukocytes (X IP/mim*) Neutrophils, % Lymphocytes, % Bands, % Eosinophils, % Basophils, % Monocytes, % Atypical, % Nucleated RBC, % Erythrocyte osmotic fragility (NaCl ]e 6.17 0.14*1.5 0.7 46.1 0.8 14.0 0.3 5.0 0.5 11.8 2.9 86.3 3.3 0.3 0.2 0.9 0.4 0 l.l 0.6 0 0 0.381 0.004 Number of rata per period. b Mean standard error. Concentration of NaCl that hemolyaed SO% of the erythrocytes. Treatment Week 8 (N - 8) 6.33 0.19 0.8 0.3 44.6 1.2 14.6 0.3 7.6 1.3 21.7 5.6 75.4 5.3 0 1.3 0.4 0 1.6 0.6 0 0 0.391 0.008 13 (N - 24) 6.42 0.29 1.4 0.1 44.6 0.3 16.0 0.1 8.0 0.6 13.1 1.5 84.1 1.6 0.1 0.1 0.5 0.2 0 2.1 0.4 0 0.1 0.1 0.400 0.004 TABLE 6 Hematology of Rats Fed Paint Chips Containing 0.08% Lead as Lead Octoate Analyses 4 (N 4)* Erythrocytes (X 10*/mm*) Reticulocytes, % Hematocrit, vol. % Hemoglobin, gm % Leukocytes (X 10*/mm*) Neutrophils, % Lymphocytes, % Bands, % Eosinophils, % Basophils, % Monocytes, % Atypical, % Nucleated RBC. % Erythrocyte osmotic fragility [NaCl]e 6.14 0.32b 0.9 0.5 41.3 0.9 14.1 0.4 5.1 0.8 24.5 1.6 74.3 1.8 0 0.8 0.3 0 0.5 0.5 0 0 0.381 0.005 Number of rats per period. k Mean * standard error. Concentration of NaCI that hemofyaed 90% of the erythrocyte* Treatment Week 8 (N -4) 6.33 0.09 l .0 0.5 46.0 0.7 15.4 0.2 5.5 0.7 20.3 4.7 76.3 4.7 0 1.5 0.6 0 2.0 0.8 0 0 0.410 0.007 13 (N - 12) 5.92 0.39 1.4 0.2 43.0 0.5 14.7 0.8 7.7 0.9 16.3 1.7 80.9 1.8 0.3 0.2 0.7 0.3 0 1.9 0.5 0 0 0.395 0.005 13 TABLE 7 Hematology of Rats Fed Paint Chips Containing 0.53% Lead as Lead Octoate Analysis 4 (N -4)* Erythrocytes (X lff/mm*) Reticulocytes, % Hematocrit, vol. % Hemoglobin, gm % Leukocytes (X HP/mm*) Neutrophils, % Lymphocytes, % Bands, % Eosinophils, % Basophils, % Monocytes, % Atypical, % Nucleated RBC, % Erythrocyte osmotic fragility [NaCl]e 6.27 0.2b 0.9 0.7 42.3 0.7 14.2 0.2 5.0 1.4 15.8 3.8 83.0 4.4 0 0.8 0.3 0 0.5 0.5 0 0 0.383 0.006 Number of rats per period. b Mean standard error. Concentration of NaCl that hemoiyxed 30% of the erythrocytes. Treatmrt Wade 8 (N -4) 6.04 0.31 0.9 0.4 43.8 0.5 14.9 0.3 7.5 2.8 19.3 3.8 77.5 3.8 0 l .0 0.4 0 2.3 0.5 0 0 0.388 0.012 13 <N - 12) 5.6 0.4 1.6 0.2 43 0.7 15.3 0.3 8.3 1.0 16.2 1.9 81.4 1.8 0.10.1 0.8 0.3 0 1.6 0.3 0 0 0.401 0.006 TABLE 8 Hematology of Rats Fed Paint Chips Containing 2.05% Lead as Lead Octoate Analyses 4 (N -4)* Erythrocytes (X 101 mm3) Reticulocytes, % Hematocrit, vol. % Hemoglobin, gm % Leukocytes (X 10* mma) Neutrophils, % Lymphocytes, % Bands, % Eosinophils, % Basophils, % Monocytes, % Atypical, % Nucleated RBC, % Erythrocyte osmotic fragility (NaCl ]c 6.30 0.2" l.t 0.6 41.8 0.5 14.4 0.2 5.1 1.1 13.5 3.0 85.8 3.2 0 0.8 0.5 0 0 0 0 0.381 0.006 Number of rats per period. Mean standard error. Concentration of NaC! that hemoiysed 30% of the erythrocytes. Treatmcat Week 8 (N -4) 6.46 0.08 0.7 0.1 45.0 0.4 15.5 0.2 ' 6.7 1.7 13.0 2.1 85.0 2.3 0 0.3 0.3 0 1.8 0.9 0 0 0.399 0.008 13 (N - 12) 6.72 0.42 2.0 0.6 43.4 0.8 15.6 0.3 8.1 0.7 14.1 2.6 82.8 2.8 0 0.9 0.3 0 2.2 0.7 0 0 0.393 0.006 14 TABLE 9 Hematology of Rats Fed Paint Chips Containing 0.42% Lead as Lead Chromate A inly-- 4 (N-)` Erythrocytes (X lOVmm*) Reticulocytes, % Hematocrit, vol. % Hemoglobin, gm % Leukocytes (X 10*/mm*) Neutrophils, % Lymphocytes, % Bands, % Eosinophils, % Basophils, % Monocytes, % Atypical, % Nucleated RRC, % Erythrocyte osmotic fragility, [NaCl]0 6.71 0.16" 0.9 0.8 43.3 0.6 14.7 0.4 5.1 0.6 8.5 1.7 90.3 2.0 0 0 0 1.3 0.8 0 0 0.383 0.003 Number of rats per period, except where indicated ocherwiee. * Mean standard error. Concentration of NaO that hemoiyzcd 30% of the erythrocytes. TreatraoM Week (N -4) 6.18 0.16 0.8 0.2 45.0 1.1 15.1 0.3 5.1 0.5 19.0 2.0 79.5 1.3 0 0.8 0.8 0 0.8 0.8 0 0.3 0.3 0.395 0.12 13 (N - 12) 6.6 0.3 1.6 0.2 43.6 0.7 15.6 0.3 6.9 0.7 14.3 2.1 83.4 2.0 0 1.2 0.4 0 1.2 0.4 0 0 0.392 0.007 t TABLE 10 Hematology of Rats Fed Paint Chips Containing 1.95% Lead as Lead Chromate Analyses Erythrocytes (X 10*/mm*) Reticulocytes, % Hematocrit, vol. % Hemoglobin, gm % Leukocytes (X 10*/mm*) Neutrophils, % Lymphocytes, % Bands, % Eosinophils, % Basophils, % Monocytes, % Atypical, % Nucleated RBC, % Erythrocyte osmotic fragility, [NaCl]0 4 (N 4) 6.17 0.05" 0.8 0.4. 40.8 0.6 13.9 0.2 4.9 0.8 10.0 2.4 92.0 1.8 0 0.5 0.3 0 0 0 0 0.383 0.007 TreatMat Week 8 (N-4) 6.21 0.13 0.8 0.3 44.3 0.3 15.3 0.3 6.1 1.2 18.5 6.6 80.5 6.6 0 0.3 0.3 0 0.8 0.3 0 0 0.385 0.007 13 (N - 12) 6.37 0.52 1.2 0.2 44.1 0.7 16.2 0.4 8.2 1.0 11.4 2.3 85.9 2.2 0 1.5 0.5 0 1.2 0.3 0 0 0.404 0.005 Concentration of Nad that hemdlyani 30% of tha erythrocytes. \ 15 TABLE 11 Hematology of Rats Fed Paint Chips Containing 12.43% Lead as Lead Chromate Analyses 4 (N -4)* Erythrocytes (X 10*/mm') Reticulocytes, % Hematocrit, vol. % Hemoglobin, gm % Leukocytes (X 10*/mm*) Neutrophils, % Lymphocytes, % Bands, % Eosinophils, % Basophils, % Monocytes, % Atypical, % Nucleated RBC, % Erythrocyte osmotic fragility [NaCl ]* 6.32 * 0.14b 1.95 * 1.28 41.3 * 1.1 13.9*0.4 4.8*0.5 21.5 6.3 78.0*6.0 0 0.5 0.5 0 0 0 0 0.384 * 0.007 Number of rats per period. b Mean standard error. Concentration of NaCl that hemotyzcd 50% of the erythrocytes. Treatment Week 8 (N -4) 6.23 *0.18 0.9*0.1 43.8*0.5 15.2*0.1 5.3 * 1.8 15.0*2.1 82.8 * 2.0 0 1.0*0 0 1.3 *0.3 0 0.3 *0.3 0.385 *0.010 13 <N - 12) 6.61 *0.38 1.6*0.2 44.1 0.7 15.8*0.2 7.6*0.6 12.8* 1.6 84.8*1.7 0.1 *0.1 1.0*0.4 0 1.3*0.3 0 0 0.396 * 0.006 TABLE 12 Hematology of Rats Fed Paint Chips Containing 66.05% Lead as Lead Carbonate Analyte* Erythrocytes (X 10`/mm`) Reticulocytes, % Hematocrit, vol. % Hemoglobin, gm % Leukocytes (x 10*/mm*) Neutrophils, % Lymphocytes, % Bands, % Eosinophils, % Basophils, % Monocytes, % Atypical, % Nucleated RBC, % Erythrocyte osmotic fragility [NaCl] * 4 (N-3)* 5.94* 0.56 0.4 *0.2 41.3 *0.9 13.9*0.5 4.3 * 1.2 14.3 * 4.1 82.0*5.6 0 0.7 *0.7 0 3.0* 2.0 0 0 0.388 * 0.009 Treatment Week S (N - 4) 6.13*0.06 1.1 *0.3 44.0* 1.5 15.0*0.2 5.0 *0.9 15.0*4.1 84.0*4.2 0 0.5 *0.5 0 0.5 *0.3 0 0 0.394 * 0.012 13 (N - 12) 6.60*0.37 2.9* 1.3 44.7* 1.2 15.6*0.6 7.7*0.5 15.2*2.6 82.7*2.7 0.2*0.1 0.9 0.3 0 1.0*0.3 0 0.1 *0.1 0.397 * 0.005 Number of rats per period. b Mean standard error. Concentration of NaCl that hemotyzcd 50% of the erythrocytes* 16 TABLE 13 Hematology of Rats Fed NBS Lead Paint Containing 11.92% Lead Treatment Week Anslyiei 4 (N -4)* 8 (N -4) Erythrocytes (X lOVmm*) Reticulocytes, % Hematocrit, vol. % Hemoglobin, gm % Leukocytes (X lOVmm*) Neutrophils, % Lymphocytes, % Bands, % Eosinophils, % Basophils, % Monocytes, % Atypical, % Nucleated RBC, % Erythrocyte osmotic fragility [NaCl]d 5.72 0.l5b 2.5 0.3 39.7 0.8 13.6 * 9.7 1.4 9.5 2.1 90.2 2.3 0.3 0.3 0 0 0 0 0 0.389 0.006 4.49 0.83 1.0 0.4 42.8 1.1 14.7 0.3 6.7 1.2 7.0 1.7 92.0 2.1 0 0 0 1.0 0.7 0 0 0.412 0.006 Number of rats per period, except where indicated otherwise. b Mean standard error. Two rats. 4 Concentration of NaCl that hemotyaed 50% of the erythrocytes. Signifiesmly different from control (P < 0.0S) as shown by Dunnett's multiple-comparisen test following an analysis of variance. 13 (N - 12) 5.63 0.34 1.3 0.1 42.9 0.4 14.7 0.1 7.0 0.5 14.2 2.1 83.6 2.2 0 l .4 0.4 0 0.8 0.3 0 0.1 0.1 0.408 0.005 TABLE 14 Tissue and Fluid Chemistry of Rats Fed Paint Chips Containing No Lead Analyses Serum electrophoresis Albumin, % Alpha l globulin, % Alpha 2 globulin, % Beta globulin, % Gamma globulin, % Total protein, gm % Albumin/globulin ratio Erythrocyte ALAD, Mmol. PBG/ Males: 100 ml RBC/hr Females: Total: Protoporphyrin, Mg/100 ml RBC Urine Coproporphyrin, Mg/' 24 hr ALA, Mg/24 hr * Number of rata per period, except where indicated otherwise. b Mean standard error. * Four rats. * Twelve rats. 4 (N-8)* 43 l " 28 1 5 1 20 1 6 1 5.4 0.1 0.76 0.03 23.2 2.3 16.6 3.1' 19.9 2.2 19.6 1.6 2.5 1.2 78.0 7.4 Treataort Week 8 (N -8) 43 2 23 1 5l 20 1 10 1 6.2 0.2 0.77 0.07 15.1 db 2.3 16.3 2.2* 15.8 1.5 23.5 1.9 3.3 7.4 83.3 11.0 13 (N m 24) 48 1 21 1 5l 21 1 6 1 6.3 0.1 0.93 0.04 14.5 1.4* 15.4 0.7* 15.0 1.0 29.2 2.0 6.0 1.9 43.4 5.0 - i `i 17 TABLE IS Tissue and Fluid Chemistry of Rats Fed Paint Chips Containing 0.08% Lead as Lead Octoate 1 l AaalyMt Serum electrophoresis Albumin, % Alpha 1 globulin, % Alpha 2 globulin, % Beta globulin, % Gamma globulin, % Total protein, gm % Albumin/globulin ratio Erythrocytes ALAD, Mmol. PBG/ Males: 100 ml RBC/hr Females: Total: Protoporphyrin, Mg/100 ml RBC Urine Coproporphyrin, Mg/24 hr ALA, Mg/24 hr Number of rats per period, except where indicated otherwiaa. k Mean standard error. Two rata. 4 Six rata. 4 (N-4)* 40 1" 26 1 5 1 21 1 8 l 5.9 0.1 0.66 0.02 24.8 7.7* 19.5 4.4 22.2 3.9 28.4 2.4 1.2 0.2 86.4 16.6 s (N 4) 44 3 20 2 4 1 20 1 12 1 6.3 0.2 0.79 0.08 14.9 1.3* 18.7 0.3* 16.8 1.2 24.2 1.6 4.8 2.4 107.6 34.1 TABLE 16 Tissue and Body Fluid Chemistry of Rats Fed Chips Containing 0.53% Lead as Lead Octoate Analyst! Serum electrophoresis Albumin, % Alpha 1 globulin, % Alpha 2 globulin, % Beta globulin, % Gamma globulin, % Tout protein, gm % Albumin/globulin ratio Erythrocytes ALAD, ><mol. PBG/ Males: 100 ml RBC/hr Females: Total: Protoporphyrin, Mg/100 ml RBC Urine Coproporphyrin, Mg/24 hr ALA, Mg/24 hr 4 (N -4>- 41 2 26 1 5 1 21 1 8 1 5.7 0.1 0.68 0.04 21.4 6.3* 15.5 2.7* 18.4 3.3 23.1 1,0 10.7 5.9 97.4 19.2 Tmfl Wtfc (N-4) 41 4 23 3 6 2 20 1 11 2 6.3 0.1 0.70 0.13 10.3 0.8* 15.3 0.2* 12.8 1.5 21.7 1.1 1.1 0.6 101.4 30.1 k Menu standard error. Two rata. * Sin rata. 18 13 <N - 12) 48 1 20 1 5 l 22 1 71 6.2 0.1 0.93 0.04 12.0 2.2 4 16.1 1.3 d 14.0 1.4 22.8 2.5 2.9 1.4 35.0 6.7 13 (N-12) S0 1 20 I 4 1 20 1 7 1 6.0 0.1 1.00 0.07 12.5 0.7 d 17.0 1.24 14.7 0.9 27.7 3.3 4.9 2.4 50.5 6.6 TABLE 17 Tissue and Body Fluid Chemistry of Rats Fed Paint Chips Containing 2.05% Lead as Lead Octoate Aittlysas Scrum electrophoresis Albumin, % Alpha 1 globulin, % Alpha 2 globulin, % Beta globulin, % Gamma globulin, % Total protein, gm % Albumin /globulin ratio Erythrocytes ALAO, Mmol. PBG/ Males: 100 ml RBC/hr Females: Total: Protoporphyrin, Mg/100 ml RBC Urine Coproporphyrin, Mg/24 hr ALA, Mg/24 hr Number of rats per period, except where indicated otherwise. b Meen standard error. Two rets, 4 Sis rats. 4 (N - 4)* 41 3" 27 2 4 l 20 l 9 l 5.7 0.2 0.70 0.07 24.1 4.0 18.7 l.0 21.4 2.3 29.5 2.8 1.6 0.6 80.7 17.3 Treatnort Week 8 (N -4) 46 2 22 1 4 1 19 1 9 l 6.0 0.1 0.85 0.07 12.1 1.7* 11.3 0.2' 11.7 0.7 30.8 2.5 3.0 0.8 82.7 10.4 TABLE 18 Tissue and Body Fluid Chemistry of Rats Fed Paint Chips Containing 0.42% Lead as Lead Chromate 13 <N - 12) 48 2 20 1 6 1 21 1 6 l 6.2 0.1 0.96 0.07 11.4 0.8 16.3 3.9* 13.8 2.0 24.0 2.2 7.7 2.9 64.5 8.8 1 1 Aoalyw Serum electrophoresis Albumin, % Alpha 1 globulin, % Alpha 2 globulin, % Beta globulin, % Gamma globulin, % Tout protein, gm % Albumin/globulin ratio Erythrocyte ALAD, Mmol. PBG/ Males: 100 ml RBC/hr Females: Total: Protoporphyrin, Mg/100 ml RBC Urine Coproporphyrin, Mg/24 hr ALA. Mg/24 hr Number of rats per period, encept where indicated otherwise. Mean standard error. Two rats. 4 Six rats. 4 (N -- 4) 42 2" 28 1 4 1 19 1 83 5.8 0.2 0.71 0.06 23.4 3.5 13.4 0.9* 18.4 3.3 27.3 2.8 8.2 ;6.7 69.3 6.6 8 (N-4) 44 2 20 2 4 1 19 1 12 2 6.0 0.2 0.80 0.08 14.1 0.6* 17.4 0.1* 15.7 1.0 28.3 0.6 1.5 0.7 65.2 17.4 13 (N-12) 47 1 22 1 S1 21 1 6 l 6.1 0.1 0.90 0.03 15.7 1.5* 16.5 1.4* 16.1 1.0 27.9 2.1 6.3 2.2 85.3 31.4 19 TABLE 19 Tissue and Body Fluid Chemistry of Rats Fed Paint Chips Containing 1.95% Lead as Lead Chromate Analytes Serum electrophoresis Albumin, % Alpha l globulin, % Alpha 2 globulin, % Beta globulin, % Gamma globulin, % Total protein, gm % Albumin/globulin ratio Erythrocyte ALAO, Mmol. PBG/ Males: 100 ml RBC/hr Females: Total: Protoporphyrin, Mg/'100 ml RBC Urine Coproporphyrin, Mg/24 hr ALA, Mg/24 hr Number of rata per period, except where indicated otherwise. Mean t standard error. Two rata. Six rata 4 (N - *) 41 db 2b 25 1 4 1 20 1 9 1 5.7 0.1 0.73 0.06 29.5 3.1 20.4 4.3e 24.9 3.4 26.5 4.7 0.9 0.1 80.8 7.2 Treatment Week 8 (N m 4) 45 1 19 1 4 1 20 1 11 1 6.20 0.04 0.81 0.04 12.3 1.0* 14.7 0.6* 13.5 0.8 26.8 1.8 7.0 6.4 67.7 6.8 TABLE 20 Tissue and Body Fluid Chemistry of Rats Fed Paint Chips Containing 12.43% Lead as Lead Chromate Analyms Serum electrophoresis Albumin, % Alpha 1 globulin, % Alpha 2 globulin, % Beta globulin, % Gamma globulin, % Total protein, gm % Albumin/globulin ratio Erythrocyte ALAD, Mmol. PBG/ Males: 100 ml RBC/hr Females: Total: Protoporphyrin, Mg/100 ml RBC Urine Coproporphyria, Mg/24 hr ALA, Mg/24 hr * Number of rets per period, except where indicated otherwise. * Mean standard error. Two rata. * Six rata. 4 (N -- 4) 40 2b 27 1 3 1 22 1 8 l 5.6 0.1 0.68 0.05 26.4 7.4' 14.3 3.2' 20.3 4.9 25.5 1.6 2.6 1.8 89.7 19.3 Trt.fi Wttfc 8 (N -4) 47 3 21 1 4 l 18 1 92 6.1 0.1 0.90 0.12 16.5 1.4* 13.4 3.8* 15.0 1.9 24.2 2.6 0.9 0.1 78.4 6.8 20 \ 13 (N - 12) 47 2 19 2 5 l 23 1 6 1 6.4 0.1 0.94 0.08 13.3 1.4 12.9 2.3 13.1 1.3 27.4 1.5 . 4.4 1.9 66.5 17.5 13 (N-12) 46 2 21 1 5 1 22 1 6 1 6.4 0.1 0.88 0.06 12.6 1.6 13.7 1.1 13.1 1.0 24.6 2.0 2.6 0.8 49.7 12.5 TABLE 21 Tissue and Body Fluid Chemistry of Rats Fed Paint Chips Containing 66.05% Lead as Lead Carbonate Treatment Week Analyses 4 (N - 3) a (N -4) Serum electrophoresis Albumin, % Alpha l globulin, % Alpha 2 globulin, % Beta globulin, % Gamma globulin, % Total protein, gm % Albumin/globulin ratio Erythrocyte ALAD, Mmol. PBG/ Males: 100 ml RBC/hr Females: Total: Protoporphyrin, Mg/100 ml RBC Urine Coproporphyrin, Mg/24 hr ALA, Mg/24 hr 41 6 27 1 3 1 21 2 82 5.4 0.2 0.73 0.17 12.3* 9.1 2.1 d 10.2 1.6' 23.2 0.9 2.0 0.7 90.3 27.7 45 l 21 2 4 1 19 1 10 1 6.0 0.06 0.82 0.04 4.4 0.1 d 12.4 0.4d 8.4 2.3' 20.4 2.1 0.8 0.3 72.3 13.4 Number of rats per period, except where indicated otherwise. Mean standard error. One rat. 4 Two rata. Six rats. * Significantly different from control (P < 0.0S) as shown by Dunnctt's multiple-comparison test following an analysis of variance. 13 (N - 12) 47 2 22 1 5 1 20 I 7 1 6.3 0.1 0.86 0.06 5.4 1.0* 7.4 0.8 6.4 0.7' 27.2 6.8 6.7 3.2 42.2 8.8 TABLE 22 Tissue and Body Fluid Chemistry of Rats Fed NBS Lead Paint Containing 11.92% Lead TrettaM Week Analytes 4 (N -4)* a (N -4) 13 (N - 12) Serum electrophoresis Albumin, % Alpha ! globulin, % Alpha 2 globulin, % Beta globulin, % Gamma globulin, % Total protein, gm % Albumin/globulin ratio Erythrocyte ALAD, Minot. PBG/ Males: 100 mi RBC/hr Females: Total: Protoporphyrin, Mg/100 ml RBC Urine Coproporphyrin, Mg/24 hr ALA, Mg/24 hr 52 1 b 21 l 4 1 20 1 3 1 5.4 0.2 l.l 0.03 8.5 5.0' 10. t 0.1' 9.3 2.1* 14.8 4.3 2.0 0.8 110.1 21.5 44 2 21 2 85 21 3 6 1 6.0 0.2 0.78 0.06 5.0 0.3 15.0 5.1* 10.0 3.6 24.5 1.8 6.8 4.9 72.0 13.6 44 2 24 1 7 l 21 1 51 6.1 0.1 0.82 0.06 4.9 0.6* 8.8 l.0d 6.9 0.8' 26.3 1.2 4.6 2.1 51.3 3.6 Number of rets per period, except where indicated otherwise. Mean standard error. Two rats. Six rata. Significantly different from control (P < 0.05) as indicated by Dunneu's multipfe-comparisoa tees following an analyse of variance. 21 T TABLE 23 Summary of Porphyrin Metabolism in Rats Fed Paint Chips for 13 Weeks Containing Different Concentrations of Lead Enrimer* Uriaarr DM Control 0.08% Lead Octoate 0.53% Lead Octoate 2.05% Lead Octoate 0.42% Lead Chromate 1.95% Lead Chromate 12.43% Lead Chromate 66.05% Lead Chromate 11.92% NBS Lead Paint ALAD* OsaoL PBG/100 Protoporpfcjnte Coproporphyrii N ad RBC/fcr) Otf/IOOad RBO 0*f/24 fcr) 24 15.0 1.0* 29.2 2.0 12 14.0 1.4 22.8 2.5 12 14.7 0.9 27.7 3.3 12 13.8 2.0 24.0 2.2 12 16.1 1.0 27.9 2.1 12 13.1 1.3 27.4 1.5 12 13.1 1.0 24.6 2.0 12 6.4 0.7* 27.2 6.8 12 6.9 0.8* 26.3 1.2 6.0 1.9 2.9 1.4 4.9 2.4 7.7 2.9 6.3 2.2 4.4 1.9 2.6 0.8 6.7 3.2 4.6 2.1 Ammotevutinfc add dehydrate. t-AmindevuUaJc add. Number of mta par dint. Avaraps standard trror of number of rata indicated. Significantly different from control Cl* < 0.05) as shown by Ounnatt's multiple-comparison teat following an analysis of variance. ALA* 0*/24 tar) 43.4 5.0 35.0 6.7 50.5 6.6 64.5 8.8 85.3 31.4 66.5 17.5 49.7 12.5 42.2 8.8 51.3 3.6 TABLE 24 Urinalysis of Rats Fed Paint Chips Containing No Lead Protein: Negative < 100 mg% > 100 mg % Microscopic Examination RBC : Normal Moderate Excessive WBC : Normal Moderate Excessive Epithelium b: Normal Moderate Excessive Crystals*: Normal Moderate Excessive Casts: Negative Positive 4 7 1 Normal. 10 or Normal. S or Normal. 22 10*100 c o Mk lasaadte. > 100 ceUa/fidd ( X440). --------- - 5-29 cede; eaeaadve. >25 ceito/ftaid (XI00). t-5 cryssale; sirenivs. >5 cryatila/iald (XlOO). a 13 6 20 24 23 1 21 2 1 24 23 1 24 \ TABLE 25 Urinalysis of Rats Fed Paint Chips Containing 0.08% Lead as Lead Octoate Tiwt--t Wck Protein: Negative < 100 mg % > 100 mg % Microscopic Examination RBC *: Normal Moderate Excessive WBC : Normal Moderate Excessive Epithelium b: Normal Moderate Excessive Crystalsc: Normal Moderate Excessive Casts: Negative Positive 4_______________a 43 1 23 2I 44 24 2 44 Numbers indicate number of rats at response level. Normal. 10 or less cells; moderate. HM00 cells: excessive. > 100 celts/fleld (X440). Normal. 3 or less ceils: moderate. 3-23 cells: excessive. >25 celts/fleld (Xl00). Normal, none; moderate. 1*3 crystals; excessive. >5 crystals/fleld (XlOO). ta 10 2 10 2 12 U l 12 23 TABLE 26 Urinalysis of Rais Fed Paint Chips Containing 0.53% Lead as Lead Octoate 4 Protein: Negative < 100 mg % > 100 mg % Microscopic Examination RBC *: Normal Moderate Excessive WBC : Normal Moderate Excessive Epithelium b: Normal Moderate Excessive Crystalse: Normal Moderate Excessive Casts: Negative Positive 4 2 l 1 4 4 3. l 4 Numbers indicate number of rats at response level. Normal. 10 or lew cells; moderate. 10-100 cells: exceanve. >100 ceils/field (X440). Normal. S or less cells; moderate. 5-23 cells; excesnve. >23 ceils/ftetd (XI00). Normal, none; moderate, t-5 crystals; excesrivc. >3 crysuis/Held (X100). Treatment Week 8 3 1 2 2 l 3 4 4 4 13 10 l 1 10 l 1 9 3 12 12 12 24 TABLE 27 Urinalysis of Rats Fed Paint Chips Containing 2.05% Lead as Lead Octoate Treatment Week _________________________________________ 4________________________ Protein: Negative < 100 mg % > 100 mg % Microscopic Examination RBC *: Normal Moderate Excessive WBC *: Normal Moderate Excessive Epithelium b: Normal Moderate Excessive Crystalsc: Normal Moderate Excessive Casts: Negative Positive 44 44 33 l l 44 24 2 44 Numbers indicate number of rats at response level. * Normal. 10 or leas cells; moderate. 10-100 cells: excessive. > 100 ceils/fteld (X440). * Normal, 5 or less ceils: moderate. 5-25 ceils; excessive. >25 cetls/Seld (XtOOh * Normal, none; moderate, 1-5 crystals; excessive. >5 crystals/field (X100). 13 ii i 12 8 4 12 12 12 25 TABLE 28 Urinalysis of Rats Fed Paint Chips Containing 0.42% Lead as Lead Chromate 4 Protein: Negative < 100 mg % > 100 mg % Microscopic Examination RBC *: Normal Moderate Excessive WBC : Normal Moderate Excessive Epithelium b: Normal Moderate Excessive Crystals e: Normal Moderate Excessive Casts: Negative Positive 4 3 l 2 2 4 2 1 l 4 Numbers indicate number of rats at response level. Normal. 10 or less ceils; moderate. 10-100 cells; exceanve. > 100 cetls/fletd (X440). Normal. 5 or teas cells; moderate. .*1-25 cells; exceedve. >25 cells/Held (XlOO). Normal, none; moderate. 1-5 crystals; exceadve. >5 crystals/Held (XlOO). tWMk 2 2 l 3 3 1 4 4 4 13 10 l l 8 3 l 8 1 3 12 12 12 26 TABLE 29 Urinalysis of Rats Fed Paint Chips Containing 1.95% Lead as Lead Chromate 4 Protein: Negative < 100 mg % > 100 mg % Microscopic Examination RBC : Normal Moderate Excessive WBC : Normal Moderate Excessive Epithelium b: Normal Moderate Excessive Crystalsc: Normal Moderate Excessive Casts: Negative Positive 3 l 4 2 2 4 4 4 Numbers indicate number of rats at response level. Normal, 10 or less ceils: moderate, 10-100 ceils: excessive. > 100 celts/ftetd (X440). b Normal. 5 or less cells; moderate. 9-23 cells: excessive. >29 cells/field (X100). Normal, none; moderate. 1-9 crystals; excessive, >3 crystals/Held (X100). Treatment Week 8 3 1 3 l 3 1 4 4 4 13 11 l 12 8 3 l 12 12 12 \ . 27 TABLE 30 Urinalysis of Rats Fed Paint Chips Containing 12.43% Lead as Lead Chromate 4 Protein: Negative < 100 mg % > 100 mg % Microscopic Examination RBC : Normal Moderate Excessive WBO: Normal Moderate Excessive Epithelium b: Normal Moderate Excessive Crystals*: Normal Moderate Excessive Casts: Negative Positive i 3 4 t 3 4 2 2 4 Number* indicate number of rats at response level. Normal, 10 or less cells: moderate. 10-100 cells: excessive. > 100 cetts/fletd (X440). * Normal. 3 or less cells: moderate. S-23 celts; excessive, >29 celts/Aeld (X100). Normal, none; moderate, 1-5 crysuit; excessive. >5 cryatals/Aeld (X100). TrcaOncat Week S l 2 1 l 3 i l 2 4 4 4 13 9 3 11 I 11 l II 1 12 12 28 * TABLE 31 Urinalysis of Rats Fed Paint Chips Containing 66.05% Lead as Lead Carbonate Protein: Negative < 100 mg % > 100 mg % Microscopic Examination RBC : Normal Moderate Excessive WBC : Normal Moderate Excessive Epithelium b: Normal Moderate Excessive Crystalsc: Normal Moderate Excessive Casts: Negative Positive 4 3 l 4 2 2 4 3. 1 4 Numbers indicate number of rau at response level. Normal. 10 or less ceils; moderate. 10-100 cells: excestive. > 100 ceils/field (X440). b Normal. S or less cells; moderate. 5-25 cells; excesaive. >23 ceils/field (X100). Normal, none; moderate. 1-3 crystals; excessive. >3 crystais/fietd (X100). Treatment Week 8 4 2 2 2 2 4 4 4 13 11 1 11 1 10 2 12 12 12 29 TABLE 32 Urinalysis of Rats Fed Paint Chips Containing 11.92% Lead (NBS Lead Paint) i ramnm ncQi *________________________________________ 13_ Protein: Negative < 100 mg % > 100 mg % Microscopic Examination RBC : Normal Moderate Excessive WBC : Normal Moderate Excessive Epithelium b: Normal Moderate Excessive Crystalse: Normal Moderate Excessive Casts: Negative Positive 23 2 1 24 2 23 1 2 44 44 44 7 5 12 11 1 12 12 12 Numbers indicate number of rats at response level. Normal. 10 or less cells; moderate, 10-100 cells; exceedv*. > 100 cells/fldd (X440). v Normal. 3 or less cells; moderate, 5-23 cells; excesrive, >23 cctls/fleid (Xl00). Normal, none; moderate, 1-5 crystals; excessive, >5 crystals/field (XI00). TABLE 33 Lead Content of Whole Blood Treatnaat Week DM Control * 0.08% Lead Octoate 0.53% Lead Octoate 2.05% Lead Octoate 0.42% Lead Chromate I. 95% Lead Chromate 12.43% Lead Chromate 66.05% Lead Carbonate II. 92% NBS Lead Paint 4* 8* u* (#) 13.1 0.9 (16)12.8 ds 0.8 (8) 16.4 2.4 (7) 14.5 1.5(8) 13.2 . 1.0 (8) 12.0 1.4(8) 19.4 2.2 (8)* 24.9 2.2(8)* 23.9 db 1.3 (12) h Values deleted due to contamiaetson. h Four samples were omitted due to contamination. Number of rat Moods analysed per group unless indicated otherwise. < Sixteen Mood samples were analysed. Average * of lead/100 ml Mood standard error of number of rats shown in parenthesis. < One Mood sample loot. e Significantly different from control (P < 0.03) as shown by Dunnstt's multiple-comparison test following an analysis of venence. 6 Twelve Mood samples analysed. 30 TABLE 34 Lead Content of Brain 4 Diet (4)* Control b 0.08% Lead Octoate 0.53% Lead Octoate 2.05% Lead Octoate 0.42% Lead Chromate 1.95% Lead Chromate 12.43% Lead Chromate 66.05% Lead Carbonate 11.92% NBS Lead Paint n.d.e n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. Number of brains analyzed per group unless indicated otherwise. *> Eight brains were analyzed at 4 und g weeks. Twenty-four brains were analyzed at 13 weeks. * Not detectable. Below sensitivity of 0.07 Mg. gm of brain. Average Mg of lead, gm brain standard error number of rats shown in parenthesis. Treatment Week 8 (4) n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. TABLE 35 Lead Content of Liver Treatment Week 48 Diet (4)` (4) Controlb 0.08% Lead Octoate 0.53% Lead Octoate 2.05% Lead Octoate 0.42% Lead Chromate 1.95% Lead Chromate 12.43% Lead Chromate 66.05% Lead Carbonate 11.92% NBS Lead Paint n.d.c n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. Number of livers analyzed per eroup unless indicated otherwise. *> Eight livers were analyzed at 4 and t weeks. Twenty-four livers were analysed at 13 weeks. Not detectable. Below sensitivity of 0.07 n</gm Uver. <* Values arc average Mg of lead/ grn Uver standard error of number of rats shown in parenthesis. 13 (12) n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 0.2 0.ld (7) 13 (12) n.d. n.d. n.d. n.d. n.d. n.d. n.d. l.l 0.6* (2) 0.4 db 0.1 (9) 31 \ TABLE 36 Lead Content of Kidney Treatment Week 48 Diet (4)* (4) Controlb 0.08% Lead Octoate 0.53% Lead Octoate 2.03% Lead Octoate 0.42% Lead Chromate 1.95% Lead Chromate 12.43% Lead Chromate 66.05% Lead Carbonate 11.92% NBS Lead Paint n.d.0 n.d. n.d. n.d. n.d. nd n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. n.d. 1.4 0.1* (4) Number of kidneys analysed per group unless otherwise indicated. Eight kidneys were analysed at 4 and g weeks. Twenty-four kidneys were analysed at 13 weeks. Not detectable. Below sensitivity of 0.07 Mt/gm kidney. * No explanation for unusually high value. * Values are Mg of icad/gm kidney or average mS of lead/gm kidney standard error of number of rats shown in parenthesis. 13 (12) n.d. 0.3(1) 0.3(1) 0.4 0.1 (2) 0.5(1) 4.2* (1) 0.4 0.0 (3) 2.3 0.2(8) 1.9 0.1 (12) TABLE 37 Lead Content of Bone (Femur) Treatment Week Diet Controlb 0.08% Lead Octoate 0.53% Lead Octoate 2.05% Lead Octoate 0.42% Lead Chromate 1.95% Lead Chromate 12.43% Lead Chromate 66.03% Lead Carbonate 11.92% NBS Lead Paint 4 <4V lXO 3.1(1) n.d. n.d. 2.9(1) 0.9(1) 3.3(1) 13.0 4.1 (4) 14.9 1.5(4) 8 (4) 3.9 0.4(8) 4.2 0.6(4) 3.9 0.2 (4) 3.0 0.7 (4) 2.6 0.9 (4) 1.8 0.2 (4) 3.1 1.1(4) 16.0 2.1 (4)' 16.4 0.4 (4)' 13 (12) 3.2 0.2 (24) 3.3 0.3(12) 3.1 0.2(12) 3.9 0.5 (12) 3.8 0.6 (12) 4.1 0.5(12) 3.5 0.5 (10)* 21.7 2.4 (12)' 10.9 0.9 (12)' * Number of bones analyzed per group unless indicated otherwise. * Eight bones were analysed at 4 and I weeks. Twenty-four bones wem analyzed at 13 weeks. * Values are eg of Icad/gm bone or avenge ag of lead/gm bone d: standard error of number of mu shown in parenthesis. * Not detectable. Below sensitivity of 0.4 **/gni of bone. * Two samples Io s l ` Significantly diflbrent from control (P < 0.05) as shown by Ounnett's multiple-comparison test following an analysis of variance. 32 At 13 weeks, detectable levels of lead in the brain appeared only in the rats fed 11.92% NBS lead paint. In the liver, detectable levels of lead were found in two rats fed 66.05% lead car bonate paint chips and nine rats fed 11.92% NBS lead paint. No lead was detected in the kidneys of the control group at 13 weeks. In contrast, lead was detected in the kidneys of one to two rats in each lead octoate group and the 0.42% and 1.95% lead chromate groups. Lead was detected in the kidneys of three rats, eight rats and 12 rats in the 12.43% lead chromate paint, 66.05% lead carbonate paint, and 11.92% NBS lead paint groups, respectively. The femurs of rats fed the control diet, lead octoate or lead chromate paints exhibited very little lead at 4 weeks. However, the femurs of rats fed 66.05% lead carbonate or 11.92% NBS lead paint contained 13.0 and 14.9 jug of lead/gm of bone, respectively. At 8 weeks, the femurs of rats fed the control, lead octoate or lead chromate diets con tained similar quantities of lead, ranging from 1.84.2 jig lead/gm bone. Lead content in the femurs in the 66.05% lead carbonate and 11.92% NBS groups were 16.0 and 16.4 pg of lead/gm of bone, respectively. Both of these values were signifi cantly above control. After 13 weeks, the rats fed lead octo ate or lead chromate had no more lead in their femurs than at 8 weeks and these levels were no higher than those in the control group. The 66.05% lead carbonate group exhibited higher levels of lead in their femurs (21.7 fig lead/gm bone) than at 8 weeks. The 11.92% NBS lead paint group had less lead in their femurs (10.9 jig lead/gm bone) than at 8 weeks. The lead levels in both of these groups were significantly greater than those observed in the control rats. I. Pathology of Rata Fed Paiat Chips Containing Different Concentrations of Lead The relative organ weights of the thyroid, spleen, heart, kidneys, fiver, adrenals, brain and gonads are shown in Table 38. The Dunnett's multiplecomparison test showed that none of the relative organ weights differed from control values. The pathology of rats fed the control, 2.05% lead octoate, 12.43% lead chromate, 66.05% lead carbonate or 11.92% NBS lead paint diets for 13 weeks is shown in Tables 39-43. The control rats had a few naturally occurring lesions. Fourteen of the twenty-four (58.390%) rats had mild to moderate lymphoid hyperplasia in the lungs, characteristic of early minute pneumonia. One of these rats had a mod erate pneumonia and another one a mild emphy sema. Other lesions included an unspecific myo carditis in two rats; foci of subacute inflammation in the liver of two rats; a cross-section of a para site (roundworm) in the colon of one rat; and foci of mononuclear cell infiltration in the kidneys of two rats. The bone marrow myeloid/erythroid cell ratios (M/E) of all rats were within normal limits. The lesions observed in rats fed the 2.05% lead octoate diet were similar to the lesions seen in the control rats. Seven out of the 12 rats (58.3%) had mild to moderate lymphoid hyper plasia in the lungs and one had mild pneumonia. Four rats had mild foci of subacute inflammation in the liver characterized by a loss of several hepatic cord cells which were replaced by macro phages and lymphocytes. Another rat had a focus of inflammation in the interstitial tissue of the pancreas. The M/E ratios of.these rats were normal. The rats fed the 12.43% lead chromate diet had lesions similar to the lesions seen in the control rats. Seven of 12 rats (58.3%) had mild to moderate lymphoid hyperplasia, and one had mild pneumonia. Only one rat had a moderate unspecific myocarditis. The M/E ratios were normal. The lesions seen in the rats fed the 11.92% NBS lead paint diet were similar to those lesions seen in the control rats. Eight of 12 rats (66.7%) had different degrees of lymphoid hyper plasia in the lungs. In one rat pneumonia was evi dent. Unspecific myocarditis occurred in 2 rats while foci of inflammation in the liver were ob served in only one rat The M/E ratios were normal. In conclusion, the pathology seen in the control and treated rats were characteristic of those in a normal population of rats. No evidence of lead-induced lesions was found. n i r, . 33 TABLE 38 Relative Organ Weights of Rats Fed Diets Containing Different Concentrations of Lead in Paint Chips for 13 Weeks Control 0.08% Lead OctoBte 0.53% Lead Octoate 2.05% Lead Octoate 0.42% Lead Chromate 12.43% Lead Chromate 66.05% Lead Car- i 0.0 o o o o O o o bo o o o o o o b H *H S3 -H 3 -H 3 H 3 -H O ow-H* tO-r%H H 3 bo o o o o o o o' S3 3 3 3 3 Or nO 3 bo o o o o o o' b MM S3 -H 5 -H 3 **ro% H 3 a M 3 a bo o o O o o o' o oo o o O 3 3 3 3 o o o o o' o' o' o` o' -H -H H -H -H -H -H -H -H 88 S 8 33 8 s oo o o o o o' o o 3 oo 3 o 3 o 3 3 3 2 o o' o' o b o' o o o' 1 *H H 53 -H -H 5? -H 5 -H IN m*-TH -H n; ? bo o o o o o o o 99 1 00 1 00 1 11 j S s s 3 IN H -H -H -H -H -H H SS X ? 8 rr** 8 -H H vn SR R S bIN bIN bIN a bIN 8 5 5 s 3 IN r ? do d d o -- o b o H -H -H. H -H -H -H -H -H ss s s vr <8 a 00 p** M fN <N b b IN vfi > 'O. o o o o i) 82 r 3 3 3 8 IN 3 h i d d d d o' o' o o' o -H -H -H -H -H *H *H -H 3it 8 SI 2 - -- 2 a IN s b in b b b b b b b S3 3 O 3 3 O 3 o I?! o' b o o' o o o o H -H -H -H -H -H -H -H -H 83 S * 3 383 d d d d o' o o o OO o o o o o o o a bb o o o o o b !f -H -H -H -H -H H *H *H H as a a a a a a R o' o' o' o' o b o' o So S o o o 3 o Hf o b o' o o o o' b H -H -H *H -H * -H -H -H yg V0 2 aS do o o o b o o lit Atn mwt 4 Jmi oco v * 3 b b o* o o o o' b H -H etf 2S -H K d R ^ -H o b H R b -H oo b -H a b -H a b sa 2 - N IN IN IN IN |i af 1I ^^ mm -I < M \ Ii i \ .9 35 TABLE 40 Pathology of Rats Fed For 13 Weeks With Paint Chips Containing 2.05% Lead as Lead Octoate Rt N. 386S7888990 93 969?9e99lOO Lungs Lymphoid hyperplasia Pneumonia Liver Foci of inflammation Pancreas Foci of inflammation Bone Marrow M/E ratio 1** 2 1 1 l 1 121 1.2 1.0 1.7 1.0 1.2 1.1 1.1 1.1 1.4 1.2 1.3 1.8 Tissues not listed were normal. Severity of lesions: 1 minimal; 2-modcratc; 3-sevete; 4-very severe: db questionable. TABLE 41 Pathology of Rats Fed For 13 Weeks With Paint Chips Containing 12.43% Lead as Lead Chromate Rt No. 143 144 147 I4S 149 ISO 153 154 157 15S 159 140 Lungs Lymphoid hyperplasia Pneumonia Heart Myocarditis Bone Marrow M/E ratio 2*2 1 2 1.2 1.0 1.0 l 1.2 1.1 1 1.4 l.l 1.4 221 1.5 1.4 1.2 1.5 Tissues not listed were normal. Severity of lesions: !-minims!; 2-modemae; 3-severs; 4.very severs: ds questionable. 36 \ TABLE 42 Pathology ot Rats Fed For 13 Weeks With Paint Chips Containing 66.05% Lead as Lead Carbonate Rat No. Lungs Lymphoid hyperplasia Pneumonia Heart Myocarditis Liver Foci of inflammation Skeletal muscle Miositis Bone Marrow M/E ratio 163 166 167 168 169 170 173 174 177 17S 179 180 i i i i i i2 l 2 ll * i1 1 1.2 1.2 1.2 1.0 t.l 1.3 1.2 1.0 1.4 1.3 l.l 1.4 TABLE 43 Pathology of Rats Fed For 13 Weeks With NBS Lead Paint Chips Containing 11.92% Lead Rat No. in m 1SS MS MS Lungs Lymphoid hyperplasia Pneumonia Heart Myocarditis Liver Foci of inflammation Bone Marrow M/E ratio 2* 2 2 2 2l 1.2 1.4 1.3 1.2 1.3 TIn k ms not Hated were normnL Severity of lerione: l-mmimnl; 2-modereie; 3-eevete; 4-very severe; queerioonMe. IN 2 1.2 193 1.2 194 1.4 19S 1 l 1.3 IN 2 1.3 199 1 1.2 200 2 1.3 37 IV. Discussion The levels of lead fed to rats in the study were sufficient to produce significant elevation of body lead burden if the lead is in the form of lead ni trate.11 If we equate the amount of lead consumed by the average rat fed paint chips containing 2.05% lead octoate, 12.43% lead chromate, 66.05% lead carbonate, and 11.92% NBS lead paint diets to a 14.6 kg (3-year old) child, we find that the lead consumption would equal 39.4, 156.0, 577.8, and 147.8 mg of lead/day, respec tively. On the basis of a 2% lead paint, the total paint intake would be 2.0, 7.8, 28.9, and 7.4 gm/day respectively. Daily ingestion of these quantities of old paint containing white lead have been reported to produce lead poisoning.1 There were no changes in hematology, urinalysis or serum proteins in the rats fed lead octoate, lead chromate or lead carbonate. The rats fed the NBS lead paint did exhibit a significant reduction in hemoglobin and a mild proteinuria at 13 weeks. Otherwise, the hematology, urinalysis and serum proteins in the rats fed NBS lead paint were normal. Porphyrin metabolism was affected as early as 4 weeks in rats fed either the 66.05% lead carbonate diet or the 11.92% NBS lead paint diet as evidenced in a 50% depression of erythro cyte ALAD activity. This effect appeared to be directly related to the concentration of blood lead as has been reported by others.14aU There was one exception: blood lead in the 12.43% lead chro mate group became elevated by the 13th week, but there was no depression of ALAD activity. This discrepancy could be related to the duration of elevated blood lead or the age of the animal when blood lead became elevated. Even though erythrocyte ALAD was depressed 50%, the overall effect on porphyrin metabolism must be considered mild, since there was no concomitant change in the levels of pro toporphyrin (erythrocyte), delta-aminolevulinic acid and coproporphyrin. These observations are consistent with reports that blood lead levels greater than 40 Mg/100 ml RBC are needed be fore serious changes in porphyrin metabolism occur.14 The body lead burden of rats fed paint containing lead octoate or lead chromate was no different from control until 13 weeks. At this time lead was found in the kidneys of one to three rats on each of the lead octoate and lead chromate diets. The rats with measurable kidney lead in the lead octoate, 0.42% lead chromate or 1.95% lead chromate groups did not have concomitant in. creases in blood, brain, liver or bone lead. Thus, these rats did not have a significant increase in body lead-burden. On the other hand, the rats fed the 12.43% lead chromate diet had elevated blood lead and thus, a significant elevation of body leadburden. Since rats fed lead nitrate show elevated lead levels in blood, kidneys, bone and liver within 2 weeks,11 it appears that the lead octoate and lead chromate were either not readily absorbed or not otherwise available for absorption. Complete gross and microscopic path ology was performed on the rats that were fed the control, 2.05% lead octoate, 12.43% lead chro mate, and 11.92% NBS lead paint diets for 13 weeks. All of these rats were reletively free of lesions, and those lesions which were observed, occur naturally in rat colonies. 38 NC * nJ Conclusions Older paint formulations contained soluable lead salts. Two samples of paint chips representative of these formulations were fed to rats at 0.1% of their diets. One was supplied by the National Bureau of Standards and was removed from inter ior walls of older homes. It contained 11.92% lead. The other was an old formulation contain ing 66.05% lead carbonate. Both of these sam ples produced classical signs of lead poisoning in the rats. These signs consisted of erythrocyte ALAD depression (50%) and significant in creases in blood, kidney, bone, liver and/or brain lead. Newer paint formulations contain in soluble lead pigments and low levels of lead driers. Several samples of paint chips containing up to 12.43% lead chromate pigment and up to 2.0% lead octoate drier were also fed to rats as 0.1% of their diets. The only evidence of toxicity or effect on body burden appear in the rats fed the paint containing 12.43% lead chromate. This con sisted of an increase in blood lead, without other signs of poisoning. Paint containing 1.95% lead chromate and paint containing 2.05% lead octo ate produced no detectable changes in the rats. The quantity of lead fed as paint chips containing either 2.05% lead octoate or 1.95% lead chromate would have approximated an in take of 40 mg/day in a 3-year-old child weighing 14.6 kilograms. This daily intake has been re ported to produce lead poisoning in children if the lead was aviliable for absorption. Since the body lead-burdens of the rats fed 2.05% lead octoate or 1.95% lead chromate were not increased, it can be assumed that the lead in these paint chips was not absorbed from the gastrointestinal tract. In addition, lead in paint scraped from old dwel lings--not the newly formulated paint--deposited in the brain, even though the blood lead concen trations of both were similar. 39