Dry Feces Research Articles

Effect of Dietary Corn Bran and Autohydrolyzed Lignin on 3,2′-Dimethyl-4-aminobiphenyl-Induced Intestinal Carcinogenesis in Male F344 Rats<xref ref-type="fn" rid="FN2">2</xref><xref ref-type="fn" rid="FN3">3</xref>

The effect of dietary corn bran and autohydrolyzed lignin on 3,2'-dimethyl-4-aminobiphenyl (DMAB)-induced intestinal carcinogenesis was studied in male inbred F344 rats. Groups of weanling rats were fed semipurified diets containing 15% corn bran or 7.5% lignin or a semipurified diet without these fibers (control diet). At 7 weeks of age, all animals, except vehicle-treated controls, were given sc injections of 50 mg DMAB/kg body weight/week for 20 weeks. All animals were autopsied 20 weeks after the last injection of DMAB. The incidence of colon tumors (percentage of animals with tumors) and colon tumor multiplicity (tumors/animal) were increased in rats fed the corn bran diet as compared to the tumor incidence and multiplicity in rats fed the control diet. The incidence of small intestinal tumors was slightly lower in rats fed the corn bran diet as compared to the incidence in rats fed the control diet. The concentrations (mg/g dry feces) of fecal deoxycholic acid and total bile acids and the daily output of fecal deoxycholic acid, lithocholic acid, hyodeoxycholic acid, and total bile acids were increased in rats fed the corn bran diet as compared to the concentrations and daily output in rats fed the control diet. The incidence and multiplicity of small intestinal tumors as well as the number of colon adenocarcinomas per tumor-bearing animal were lower in animals fed the lignin diet than in those fed the control diet. Lignin had no effect on the concentrations of fecal bile acids, but the daily output of total bile acids was increased in animals fed the lignin diet as compared to the daily output in rats fed the control diet. This study thus indicates that the protection against colon cancer depends on the type of fiber.

Ingestion Rates and Aspects of Water, Sodium and Energy Metabolism in Caged Swamp Buffalo, Bubalus Bubalis, From Isotope Dilution and Materials Balances.

Exchanges of DM, sodium, water and energy were estimated on caged swamp buffalo of body mass (W) 297 plus or minus 13 kg. Estimates of feed ingestion estimated from rates of 22Na and 3H turnover were in close agreement with estimates from weighing. Tritium equilibrated in 6 h and 22Na in 12 h. Tritium space was 78.9 plus or minus 1.6% of body mass at 6 h and 83.9 plus or minus 1.1% at 24 h. The body pool of exchangable Na was 40.56 plus or minus 1.79 mmol/kg W at 12 h, and 44.62 plus or minus 2.12 mmol/kg W at 24 h. The daily rate of water turnover was 34.72 plus or minus 2.33 litres or 326.1 plus or minus 17.2 ml/kg W0.82, about three times that expected on the basis of body size, reflecting adaptation to a tropical swamp habitat. It was due mainly to the high rate of imbibition, 30.78 plus or minus 2.15 litres daily or 289.1 plus or minus 16.3 ml/kg W0.82 daily. Daily rates of water loss were partitioned as: faecal, 9.99 plus or minus 0.761 (94.1 plus or minus 7.0 ml/kg W0.82); urinary, 10.39 plus or minus 0.76 litres (98.2 plus or minus 7.6 ml/kg W0.82); pulmocutaneous, 14.34 plus or minus 1.37 litres (133.8 plus or minus 8.9 ml/kg W0.82). Swamp buffalo are unlikely to be able to satisfy their water requirements from food alone during the dry season in northern Australia. The daily rate of Na turnover was 6.29 plus or minus 0.41 mmol/kg W0.75. Na in the faeces was low, 8.3 plus or minus 0.9 mmol/kg dry faeces, indicating very effective alimentary absorption of Na. Apparent digestible energy intake (DE) per day for maintenance was about 651 plus or minus 41 kJ/kg W0.75. Daily rates of evaporative heat loss were high, 481 plus or minus 33 kJ/kg W0.75, exceeding the non-evaporative component of the DE, 321 plus or minus 35 kJ/kg W0.75; evaporative processes may have contributed to the high maintenance DE.

The effects of nematodiasis on weaner sheep in Western Victoria

The development of nematodiasis and its subsequent effect upon production from Merino weaner sheep in western Victoria was studied at Hamilton during 1975-77. In each year, all weaners were drenched in summer and allocated to groups of 36, stocked at 15 sheep ha-1. The groups were given oral anthelmintics weekly, monthly or on five, two or one occasions between March and December of each year. A further two groups were not drenched, but one of these groups was given access to anthelmintic blocks. Nematodiasis was prevalent from the commencement of continuous pasture growth in autumn until early summer. Its effect varied considerably between both years and treatments. Undrenched sheep gained 39-66% less liveweight and grew 16-30% less wool than sheep drenched weekly. In two of the three years, liveweight gain and greasy fleece weight increased with frequency of anthelmintic treatment. The mean faecal egg count (EPG) in untreated sheep during the three years was over 500 eggs g-1 dry faeces and the mean number of nematode larvae ha-1 (LPH) was c. 1 x l06. Only those groups of sheep receiving 5, 12 or weekly drenches during the experimental periods had EPG or LPH that were significantly less than those of the undrenched sheep. Two to five anthelmintic treatments between March and December gave adequate control of nematodiasis.

Effect of Dietary Wheat Bran, Alfalfa, Pectin and Carrageenan on Plasma Cholesterol and Fecal Bile Acid and Neutral Sterol Excretion in Rats

The effect of dietary wheat bran, alfalfa, pectin and undegraded carrageenan at a level of 15% on the composition of fecal bile acids and neutral sterols and on the plasma and liver cholesterol levels was studied in Fischer female rats fed a semi-purified diet based on soybean protein, cornstarch, dextrose and corn oil. The diets differed not only in type of fiber but also in amount of fiber. Plasma cholesterol levels were reduced in rats fed pectin or carrageenan diet but were not altered by the addition of wheat bran or alfalfa to the diet. Liver cholesterol levels were comparable in all groups. Diets containing wheat bran, alfalfa and carrageenan caused a significant increase in feces weight. The concentration (mg/g dry feces) of fecal bile acids, particularly hyodeoxycholic acid, β-muricholic acid, deoxycholic acid and lithocholic acid, and of neutral sterols, mainly coprostanol, was lower in rats fed wheat bran compared to those fed a control diet, but the daily output of these constituents was the same in both groups. Alfalfa had no effect on the concentration of fecal bile acids, but the daily excretion of deoxycholic acid, lithocholic acid and 12-ketolithocholic acid was increased compared to the control diet. Addition of pectin to the diet increased the concentration and daily output of fecal neutral sterols and bile acids compared to that of control diet. Carrageenan markedly increased the concentration and daily output of fecal cholesterol, deoxycholic acid and lithocholic acid, as well as the daily output of total bile acids. It is concluded that the plasma cholesterol-lowering effect and fecal bile acid and neutral sterol excretion vary with type and amount of fiber.

Effect of Gamma Irradiation on the Physicochemical Properties of Rye

The effect of irradiation (60Co) on the nutritional value of rye was determined using a chick growth assay. In vitro irradiation increased significantly the solubility of rye solids in water. Total protein (N × 6.25) was not changed appreciably by irradiation but its solubility in water was increased. Compared with non-irradiated rye, the pH of irradiated rye suspension in water was reduced. In vitro digestibility of irradiated rye protein determined by a mixture of trypsin, chymotrypsin, and peptidase was increased. Solubility of carbohydrate from rye in water was increased and viscosity of a water extract was decreased by irradiation. In vitro α-amylolysis of water extracts of the grain indicated no beneficial effect of gamma irradiation for α-amylase activity. In vitro enzymatic digestibility of a diet containing 62.55% irradiated rye was enhanced by a combined pepsin-pancreatin treatment over a non-irradiated rye containing dye. Dry feces, expressed as percentage of dry matter consumed, were less for chicks fed irradiated rye diets than for those fed nonirradiated rye diets. The nutritional value of rye, based on a chick growth assay, was significantly increased by gamma irradiation (60Co). Irradiation of rye decreased nitrogen and mineral excretion by chicks in relation to intake of these nutrients.

The effects of dehydration on electrolyte concentrations and water content along the large intestine of a small ruminant: The Dik-dik antelope

1. The concentrations of Na, K, and Cl and the water content in the large intestine and rectum of an East African ruminant, the Dik-dik antelope, was investigated in hydrated and dehydrated animals. 2. Intestinal contents were removed at six sites along the large intestine and rectum, and the water fraction and the amounts of Na, K, and Cl were measured per g dry matter. An impermeant water marker showed that the dry matter amount was nearly constant along the lower gut. Local electrolyte absorption rates were determined in the terminal colon by a dialysis bag method. 3. Approximately 4/5 of the absorption of NaCl and H2O took place in the upper large intestine. Throughout the lower gut the Na concentration of the absorbate was close to that of plasma. The Na and Cl concentrations of the digesta decreased aborally while the K concentration rose, but K was still absorbed. 4. Dehydration resulted in a reduction of 35% of the water lost per gram dry faeces. The water content was reduced from the start of the large intestine (by 13%), but the fractional absorption of salt and water in the large intestine and rectum was not significantly changed. The local electrolyte absorption rates and the electrical potential difference were slightly reduced. The Na and K concentrations of the absorbate remained nearly constant. The water saving during dehydration thus seems to proceed without specific adjustments of the transport parameters of the lower gut. The concentrations of Na and Cl in faeces approach those which in dialysis bag experiments result in zero absorption rates. This explains the constant fractional absorption of NaCl and water in the lower gut at different flow rates of dry matter. 5. Animals shot in the field were not dehydrated, but more Na-depleted than those studied in captivity. They had a pronounced net K absorption in the lower gut.

Diet, fecal bile acids, and neutral sterols in carcinoma of the colon

Increased concentrations of fecal bile acids and neutral sterols or their degradation products have been linked to certain diets and are implicated in colonic carcinogenesis. We measured fecal bile acid and neutral sterol concentrations by thin-layer and gas-liquid chromatography in 15 patients with colonic adenocarcinoma, 23 controls, and 16 patients with nongastrointestinal cancer. We compared these results with dietary intake. Detailed dietary histories showed no differences among the groups in the ingestion of calories, protein, fiber, fat, or carbohydrate. A wide variation in fecal concentration of individual bile acids and neutral sterols was found within each group, but no significant differences in the total bile acid or total neutral sterol per gram dry weight feces were found. Decreased coprostanol, coprostanone, and lithocholic acid excretion was found in the colon cancer group compared with controls. The fecal excretion of all bile acids and neutral sterols was lower significantly in the nongastrointestinal cancer patients with liver metastases as compared with those without. We conclude that total bile acid and total neutral sterol excretion is similar in the three groups, all ingesting similar diets. We cannot confirm reported increased excretion of total bile acids nor excessive bacterial conversion to degradation products in colonic cancer patients. Hepatic metastases correlate with decreased fecal excretion of both bile acids and neutral sterols, which may be due to diminished hepatobiliary excretion.

Effect of Dietary Fiber on Azoxymethane-Induced Intestinal Carcinogenesis in Rats<xref ref-type="fn" rid="FN2">2</xref>

The effect of alfalfa, bran, and cellulose on intestinal tumor formation and fecal billary steroid levels was studied in male Sprague-Dawley rats given injections of azoxymethane (AOM). Animals received weekly injections of 8 mg AOM/kg and were fed diets containing 10% fiber (wt/wt) and 35% beef fat or 20 or 30% fiber and about 6% beef fat. Control animals in each instance were fed fiber-free diets. The addition of 10% fiber to the high-fat diet did not significantly reduce the intestinal tumor frequency (average No. of tumors/rat). However, addition of 20 or 30% fiber to the 6% fat diet significantly reduced the intestinal tumor frequency. The concentration of fecal biliary steroids (mg/g dry feces) was significantly lowered in the groups with reduced tumor frequencies, whereas the total excretion of fecal biliary steroids (mg/day) did not show a similar correlation. These observations suggest that intestinal tumor frequency can be reduced by increased dietary fiber only when fat intake is not at a high level. The effect of fiber may be due to dilution of promoters and/or carcinogens in the intestinal tract.

Utilization of piggery waste III. Effects of sodium hydroxide treatment of pig faeces on chemical composition, microscopic physical characteristics, and in vitro and in vivo digestibility

Four experiments are described in which pig faeces were treated with sodium hydroxide using equal weights of alkali solution and dry faeces. In Experiment 1, levels of 0, 1, 2, 3, 5, 7, 9, 12 and 15 g NaOH/100 g dry matter (DM) were compared. Increasing amounts of sodium hydroxide caused marked reductions in the concentration of neutral detergent fibre and smaller decreases in the concentrations of acid detergent fibre and lignin. Untreated faeces had an in vitro organic matter digestibility (IVOMD) of 31%; with treatment the IVOMD increased almost linearly to 49% at 7 g NaOH/100 g DM beyond which there was no significant increase. In Experiment 2, faeces treated with 7 g NaOH/100 g DM were left to react for 1, 4, 6, 9, 12 and 14 days. The IVOMD showed little change for the first 3 or 4 days then increased steeply until approximately day 8 after which there was no further significant increase. In Experiment 3, faeces treated with 0 and 7 g NaOH/100 g DM were examined by means of a scanning electron microscope and a photo-microscope. The sodium hydroxide treatment caused obvious structural disintegration and the removal of the smooth cuticle layer of the fibres. Phloroglucin staining indicated a dispersion of lignin in the tissues. In Experiment 4, sheep were fed on diets of hay and 30% untreated faeces or 30% faeces treated with 7 g NaOH/100 g DM. The organic matter digestibility of the faeces (calculated by difference) was increased from 29 to 47% due to the increased digestibility of the fibre components, particularly hemicellulose (33 to 90%); the crude protein digestibility fell from 48 to 31%. The sheep receiving the treated diet consumed more water and had a greater urinary output which effectively excreted most of the additional sodium. Liveweight changes were in favour of the diet containing the treated faeces.

Copper coproporphyrin excretion in familial coproporphyria.

Analysis of stool specimens from a patient with familial coproporphyria by high-performance liquid chromatography revealed that 112 microgram per gram of dry feces (14% of the total porphyrin present) was copper coproporphyrin. Examination of stool specimens from other patients with this disease confirmed the presence of significant amounts of both copper coproporphyrin and coproporphyrin. Further investigation showed that the copper coproporphyrin was probably formed by a nonenzymic incorporation of copper by the coproporphyrin in either the bile or feces.

Analysis of Fecal Bile Acids and Diet Among the Japanese in Hawaii

Fecal samples of 165 Japanese men in Hawaii, age 43 to 74, were analyzed for bile acid content by their conversion to the methyl ester and the trimethylsilyl ether derivative followed by separation on a gas chromatograph. The arithmetic mean of total bile acids for the 165 specimens was 10.96 mg/g dry weight feces. Each of the following bile acids was detectable in over 77% of the fecal specimens: cholic, deoxycholic, lithocholic, and cholanic acid. The intake of Western foods was not positively correlated with the fecal content of secondary or modified bile acids, even though other workers have observed that these bile acids predominated in persons from Westernized countries. Two of the Japanese foods were negatively correlated with the levels of modified bile acids, which suggested that these foods contributed to a decrease in modified bile acids in fecal specimens. Fecal bile acid measurements appeared to be associated with age, but not with weight, height, or serum cholesterol levels.

Diagnostic value of lysozyme activity estimation in the feces of infants with acute diarrhoea.

The activity of lysozyme in feces was estimated in a control group of 50 healthy infants and in a group of 152 infants with acute diarrhoea. All infants investigated were artificially nourished. In the latter group the activity of lysozyme was estimated twice: a) at the beginning of clinically active phase of the disease and (b) in the convalescence period immediately after withdrawal of clinical symptoms. The range of normal values was 14.9--77.0 (average 44.0) of egg-white lysozyme units/g dry feces. In acute diarrhoea the activity of lysozyme in feces was found to be elevated in 72.4% of cases in the first determinations and in an additional 7.6% of cases in the second determination (i.e. a total of 80% of cases in both determinations). The average elevations of lysozyme activity in the feces and the dynamics of their normalization after withdrawal of clinical symptoms were generally related to the severity of the disease.

Studies of the Duodenal and Fecal Flora in Gastrointestinal Disorders during Treatment with an Elemental Diet

The duodenal and fecal flora were studied in 18 patients suffering from gastrointestinal disorders during treatment with an elemental diet (Vivasorb). Before treatment the duodenal flora was found to be abnormal in 6 of 17 patients. After treatment the flora remained abnormal in 2, whereas, it became normal in 4 patients, 3 of whom were suffering from ulcerative colitis. The fecal flora was uninfluenced by the diet. The overall number of colonies per gram of dry feces did not vary significantly, whether anaerobic or aerobic. The ratio of anaerobes to aerobes was significantly changed in only 3 patients. There was no correlation between changes in the duodenal and the fecal flora, on the other hand, and the final clinical result of treatment with elemental diet on the other hand. On an average, daily fecal output remained unchanged. In several cases the volume either increased or decreased, but the fecal flora was unchanged. The findings are in agreement with those made in most of the earlier studies of healthy volunteers and in one study of a patient who was suffering from ulcerative colitis.

Metabolic epidemiology of colon cancer: enzymic activity of fecal flora

Because of the potential significance of secondary bile acids and cholesterol metabolites formed by the intestinal microflora in the pathogenesis of colon cancer, fecal microbial 7alpha-dehydroxylase and cholesterol dehydrogenase activities were assayed in colorectal cancer patients, patients with adenomatous polyps, asymptomatic controls, and normal controls. The mean 7alpha-dehydroxylase activity per 100 mg of dry feces per 2 hr incubation for colorectal cancer patients was significantly greater than either asymptomatic controls or normal controls. Patients with polyps had greater activity than controls, but did not differ significantly from the cancer patients or asymptomatic controls. The mean cholesterol dehydrogenase activity for colorectal cancer patients was significantly greater than controls. Patients with polyps also had greater activity than controls. No differences in the level of fecal beta-glucuronidase activity were found among the four risk groups. These data support the concept that patients with colorectal cancer are more able to convert primary bile acids and cholesterol to microbial products in colon contents than are controls. Such differences in the activity of intestinal microflora may serve as biochemical indicators that will reflect the enzymic activity of the fecal flora as well as the key intraluminal compounds in identifying populations at different risk for developing colorectal cancer.

Water, Electrolyte, and Nitrogen Budgets of Jackrabbits (Lepus californicus) in the Mojave Desert

Seasonal changes in water flux rates (HTO) and diet (stomach content analysis) were determined in jackrabbits (Lepus californicus) kept in 1-acre (0.4-hectare) field enclosures that contained natural Mojave Desert vegetation. The water, electrolyte, and nitrogen contents of food plants were measured at different seasons. Itemized water, electrolyte, and nitrogen budgets in jackrabbits were obtained by measuring food utilization in caged animals fed natural diets. Field jackrabbits maintained body mass and obtained excess water while eating succulent annual plants in spring, but in summer and winter animals could not maintain mass or water balance while eating the drier vegetation present during those seasons. Diet utilization studies indicated that (1) jackrabbits could not maintain nitrogen balance on the winter diet, (2) ion regulation was no problem in spring or summer, and (3) jackrabbits can produce fairly concentrated urine (2.5-3.6 osM), very dry feces (38% H₂O), and can reduce evaporative water loss about 70% when water is restricted. Despite these mechanisms for conserving water, jackrabbits in the field have relatively high water requirements. We estimate that in summer a jackrabbit would require about 120 ml H₂O kg⁻¹ day⁻¹ to maintain water balance, and that its diet must contain no less than 68% H₂O in order to meet this requirement. As long as food plants contain sufficient water, their digest ibility, nitrogen, and electrolyte content will probably also be suitable.

Effect of high crude fiber intake on transit time and the absorption of nutrients in South African Negro schoolchildren

Transit time (using carmine as marker) averaged about 9.5 hours in rural South African Negro children aged 9-12 years, when ingesting a mean of 10 g crude fiber per diem on their everyday diet. A: in subgroups of 40-50 pupils, supplements of maize and wheat bran, and of wholemeal bread--each affording about 2 g fiber--also of oranges, affording 4 g fiber, decreased transit time only slightly, to about 8.5 hours. Hence, pupils current daily fiber intake, in its effect on transit time, is already acting maximally. B: mean respective fecal nitrogen and fat concentrations on everyday diet were not significantly affected when the subgroups ate one of the following fibre-free foods: 1) 40 g protein from skim milk; 2) 40 g fat from butter; 3) 40 g carbohydrate afforded by sugar. Additionally, on their usual diet, also following the ingestion of 40 g uncooked maize flour, starch was extremely seldom detected in feces. C. feces collections for 5-day periods were made on small groups of pupils (8 per group) when consuming first their everyday diet, and next when including each day one of the following: 1) 40 g protein from skim milk; 2) 40 g fat from butter; 3) 40 g sugar. On these regimens, there were no significant changes, compared with respective data on everyday diet, in mean amount of dry feces excreted daily, in concentrations of nitrogen and fat, nor in amounts of nitrogen and fat excreted daily. Yet a daily supplement of 350 g oranges (5-7 oranges), although virtually nitrogen- and fat-free but containing 4 g fiber, resulted in slightly shorter transit time but highly significant increases in mean amounts of dry feces, nitrogen and fat excreted daily. Observations suggest that the protein, fat and carbohydrate (excluding unassimilable fiber) in the supplements were virtually fully digested and absorbed. Discussion suggests that this also applied to nutrients in the everyday diet. It is judged that the large stools voided by these people (and others consuming diets high in fiber) are composed, apart from unassimilable fiber, almost wholly of endogenous products.

Effect on fecal output of various dietary nitrogen sources in pig-tailed monkeys (Macaca nemestrina) fed fiber-free, semisynthetic diets

Fiber-free liquid diets containing isonitrogenous amounts of various dietary nitrogen sources were fed to five adult male pig-tailed monkeys (Macaca nemestrina) with a mean weight of approximately 10 kg. All liquid diets supplied 3.0 g N/DAY PER MONKEY AND MAINTAINED THE ANIMALS IN A POSTIVE NITROGEN BALANCE. Initial baseline fecal output data were obtained by feeding the animals a commercial solid monkey chow. The dietary nitrogen sources fed were a) egg white protein, b) an enzymatic hydrolysate of fish protein supplemented with L-amino acids to simulate the egg albumin pattern, c) a mixture of pure L-amino acids simulating the egg pattern, d) a casein hydrolysate supplemented with amino acids, and e) an amino acid mixture with Rose's pattern. Total fecal matter, dry fecal matter, percent of moisture, fecal nitrogen, lipids and ash were determined for a 10-day period for each experimental diet. A very significant difference (P smaller than 0.001) was noted between each liquid diet and the solid chow, but no significant differences were found between the various fiber-free liquid diets, pointing to the effect of fiber as a major factor affecting fecal output. Monkeys fed liquid diets excreted fecal matter with a mean of 12.9 g/day, of which 4.7 g/day was dry feces (fecal dry matter 28.5%). Fecal nitrogen was found to be 0.25 g, fecal lipids were 0.19 g, and fecal ash was 0.59 g/day per monkey, respectively.

Candida albicansassociated with the gastrointestinal tract of the common pigeon(Columba livia)

Candida albicans was cultured from the upper gastrointestinal tract of 44% and from the lower alimentary tract in 6% of 50 common pigeons (Columba livia). Thirty per cent of samples of pigeon droppings collected from different locations were positive for the yeast. The colony forming units for positive samples ranged from 2 times 10-2-2-8times 10-6 per g dry feces. The percentage of antigenic Groups A and B for the strains of C. albicans isolated was approximately the same as for strains isolated from human sources.

New information on lead in dirt and dust as related to the childhood lead problem.

It has been known for many years that the eating of leaded paint is the prime cause of lead poisoning and elevated blood leads of children living in deteriorated housing. Recently, there has been speculation that children may eat dirt and dust contaminated with lead exhausted from cars and that this amount of ingested lead is sufficient to contribute significantly to the childhood lead problem. This paper reports on a twopart study conducted to evaluate the validity of the dirt-and-dust hypotheses. The first part of the study was made to determine the source of lead in dirt to which children are normally exposed. Dirt samples were taken in old urban areas around 18 painted frame houses and 18 houses of brick construction. Samples also were taken around seven old frame farmhouses remote from traffic. Based on the fact that lead concentrations in the dirt were similar in city and rural yards at corresponding distances from the houses, it is clear that nearly all of the lead in dirt around these houses is due to paint from the houses. Lead antiknock additives are therefore not a significant contributor to the lead content of dirt around houses where children usually play. The second part of the study used a naturally occurring radioactive tracer (210)Pb to determine the relative amounts of dust and other lead-containing materials (e.g., paint) eaten by young children. This tracer is present in very low concentrations in paint and in significantly higher concentrations in fallout dust. Stable lead and (210)Pb were analyzed in fecal material from eight children suspected of having elevated body burdens of lead and ten children living in good housing where lead poisoning is not a problem. The normal children averaged 4 mug Pb/g dry feces, with a range of 2 to 7. Of the eight children suspected of having elevated lead body burdens, two had fecal lead values within the normal range. However, the remaining six were 4 to 400 times as high. Despite these differences in fecal lead between the two groups, the groups were essentially identified in the (210)Pb content of their feces. The "elevated" children averaged 0.040 pCi of (210)Pb dry feces, while the normal group averaged 0.044 pCi/g. The results provide sound evidence that these children suspected of elevated lead body burden were not ingesting dust or air-suspended particulate.

New Information on Lead in Dirt and Dust as Related to the Childhood Lead Problem

It has been known for many years that the eating of leaded paint is the prime cause of lead poisoning and elevated blood leads of children living in deteriorated housing. Recently, there has been speculation that children may eat dirt and dust contaminated with lead exhausted from cars and that this amount of ingested lead is sufficient to contribute significantly to the childhood lead problem. This paper reports on a twopart study conducted to evaluate the validity of the dirt-and-dust hypotheses. The first part of the study was made to determine the source of lead in dirt to which children are normally exposed. Dirt samples were taken in old urban areas around 18 painted frame houses and 18 houses of brick construction. Samples also were taken around seven old frame farmhouses remote from traffic. Based on the fact that lead concentrations in the dirt were similar in city and rural yards at corresponding distances from the houses, it is clear that nearly all of the lead in dirt around these houses is due to paint from the houses. Lead antiknock additives are therefore not a significant contributor to the lead content of dirt around houses where children usually play. The second part of the study used a naturally occurring radioactive tracer 210Pb to determine the relative amounts of dust and other lead-containing materials (e.g., paint) eaten by young children. This tracer is present in very low concentrations in paint and in significantly higher concentrations in fallout dust. Stable lead and 210Pb were analyzed in fecal material from eight children suspected of having elevated body burdens of lead and ten children living in good housing where lead poisoning is not a problem. The normal children averaged 4 μg Pb/g dry feces, with a range of 2 to 7. Of the eight children suspected of having elevated lead body burdens, two had fecal lead values within the normal range. However, the remaining six were 4 to 400 times as high. Despite these differences in fecal lead between the two groups, the groups were essentially identified in the 210Pb content of their feces. The “elevated” children averaged 0.040 pCi of 210Pb dry feces, while the normal group averaged 0.044 pCi/g. The results provide sound evidence that these children suspected of elevated lead body burden were not ingesting dust or air-suspended particulate.