SEARCH · PubMed Health

Results for “Body Burden”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

PubMedDate not supplied

Impact of environmental cadmium pollution on cadmium exposure and body burden.

The body burden of cadmium, as estimated from 24-h urine cadmium levels, was determined in 1,523 subjects who were not occupationally exposed and who lived in five areas of Belgium. Urinary cadmium levels differed significantly with place of residence. These differences persisted after standardization for the other significant determinants (i.e., age, body mass index, smoking habits, social class, alcohol consumption, and menopause). The highest 24-h urine cadmium levels were found in subjects who lived in areas that contained cadmium-polluted soils. The body burden overload has been attributed mainly to the consumption of locally grown vegetables and the use of contaminated well water for cooking and drinking. Blood cadmium levels were also dependent on place of residence. However, the geographical differences in blood cadmium did not parallel those of urine cadmium. Blood cadmium is more influenced by recent exposure; therefore, this latter observation might reflect the recent implementation of preventive measures in some areas.

Adolescent↗

PubMed1985

Cadmium body burden of an occupationally non burdened population in southern Bavaria (FRG).

The cadmium body burden of the occupationally non-burdened population in the southern Bavarian area was estimated from the cadmium concentrations in liver and renal cortex, determined by ET-AAS of 263 autopsy cases. A mean value of 17.9 mg cadmium was calculated for all cases and 21.9 mg cadmium for all adults. The body burdens found do not depend on sex but greatly on smoking habits. Mean values for non-smokers are 13.5 mg, for moderate smokers 22.5 mg and for heavy smokers 33.2 mg. The dependence on age is similar to that of the cadmium concentration in the kidney cortex: an increase up to an age of approximately 50 years and a decrease at higher ages. Between the average value we found and the critical body burden calculated by Roels et al. (1983) is a safety factor of 8 to 10, but in some of our cases of middle-aged, heavy smokers this safety factor drops to a value lower than 1. It is concluded that it seems to be imperative to control the further trend of the cadmium body burden in occupationally non-burdened populations.

Adolescent↗

PubMedDate not supplied

Biological and physical factors affecting the body burden of organic contaminants in freshwater mussels.

Biological and physical factors affecting the body burdens of hexachlorobenzene, octachlorostyrene, and four polychlorobiphenyl (PCB) congeners in freshwater mussels from Lake St. Clair, Ontario, Canada were investigated. Specimens of Lampsilis radiata (Barnes) and the non-native Elliptio complanata (Lightfoot) were deployed for forty days at four Lake St. Clair sites, to investigate whether the water or the sediment phase represented the primary source of contaminants and to examine the effect of enclosure of the mussels on contaminant uptake. No significant differences in body burdens were detected for any of the compounds between mussels placed in corrals containing uncontaminated sand and those with natural sediment, suggesting the water phase represents the xenobiotic source. Among three enclosure types of varying restriction there were no significant differences in the body burden of each compound indicating the effect of confinement on uptake is minimal. Weak negative correlations between body burden and body length existed for all compounds, although there were no significant differences between the sexes or, with the exception of PCB congener 118, among five indigenous species.

Animals↗

PubMed1992

Factors influencing the cadmium body burden in a population study.

The cadmium body burden, as estimated from 24-h urinary cadmium (Cd-U), was determined in 1523 non-occupationally exposed subjects living in five areas of Belgium. It increased with age until 55-65 years in both sexes and thereafter decreased slightly. It was higher in smokers but was inversely associated with alcohol consumption and social class. In men only, it was also positively correlated with body mass index. After the menopause, women showed a significant increase in 24-h Cd-U independently of the other factors. In addition, the cadmium body burden was independently associated with place of residence in both sexes. Highest levels of Cd-U were found in subjects living in an area with soils heavily polluted by cadmium.

Adolescent↗

PubMed1990

Human body burden of polychlorinated dibenzofurans associated with toxicity based on the yusho and yucheng incidents.

The polychlorinated dibenzofurans (PCDFs) are one group of man-made toxicants for which reasonably extensive data exist relevant to dose-response relationships in humans. Examination of contaminated food oil consumption from the yusho (Japan) poisoning incident indicates the mean uptake or body burden of 2, 3, 4, 7, 8-pentachlorodibenzofuran (PnCDF) equivalents (PEQ) associated with nausea and anorexia to be 4.4 micrograms/kg body wt and that associated with chloracne to be 5.9 micrograms/kg. For the yucheng (Taiwan) poisoning incident, blood measurements for chloracne show a similar body burden of 4.0 micrograms/kg. The latter value is toxicologically equivalent to a 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent (TEQ) body burden of 2.0 micrograms/kg body wt or about 150 micrograms for an adult person. This corresponds to an adipose tissue level of about 10 micrograms/kg fat, and is comparable to that known to cause chloracne in rhesus monkeys. These body burdens on a TEQ basis are more than 200 times higher than the average current levels of PCDDs/PCDFs found in North American populations and are the first to relate human body burdens of PCDFs with a known effect and to compare them to animal data. Since the effects reported may not be the most sensitive indicator of human toxicity, lower body burdens could be associated with more subtle toxicological events.

Adolescent↗

PubMed1991

A time-dependent 2,3,7,8-tetrachlorodibenzo-p-dioxin body-burden model.

Estimates of the 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) body-burden acquired from an environment in which 2,3,7,8-TCDD has been introduced in a high concentration, are derived from an idealized linear reaction kinetic model. The model parameters are the 2,3,7,8-TCDD transfer factor from the environmental soil medium to the human body, the background intake, the soil concentration and the body and soil elimination half-times. Values of the transfer factor are estimated from reported human and environmental data. The model conservatively determines a time-scale over which the acquired body-burden may be significantly higher than the background dose caused by the ubiquitous presence of 2,3,7,8-TCDD in food, consumer products, etc. and allows comparison of the cumulative body-burden with published values for the minimum toxic dose and derived values of the minimum guideline dose. The linear nature of the model also provides a framework for the estimation of the 2,3,7,8-TCDD toxic equivalent (TEQ) body-burden acquired from environments in which a mixture of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are present.

Body Burden↗

PubMed1990

Total body burdens and tissue concentrations of lead, cadmium, copper, zinc, and ash in 55 human cadavers.

Trace metal contents of human tissues and total body burdens are useful for studies of nutrition and certain diseases. Data are summarized and analyzed for individuals exposed to the normal Cincinnati environment, for 29 tissues from 55 cadavers for lead and ash concentrations, and from 26 cadavers for cadmium, copper, and zinc concentrations. Total body burdens also were calculated and correlated against each other and age. The distributions for ash, copper, and zinc were close to normal, but those for lead and cadmium were closer to lognormal. Bone lead increased with age, whereas soft tissue lead did not. The calculated mean percentage of total body lead in the bones ranged from 78% at age 20 to 96% at age 80. Correlations of blood concentrations with total body burdens were negligible for cadmium and zinc. For copper the correlation coefficient was a poor 0.54. For lead in blood vs soft tissue burden it was a very poor 0.37, and vs total body lead it was negligible. Thus the use of blood samples as a convenient clinical measure of body burdens for these metals may be of limited value. These and other findings provide a useful bank of information for health studies.

Adult↗

PubMed1992

Assessment of accumulated body burden of metals.

Knowledge of the body burden of a metal is important for evaluation of exposure and risk. Traditionally, the burden has been estimated through levels in blood, urine, hair, or shed teeth, or by mobilization tests. However, all these methods have limitations. In vivo methods for determination of cadmium in kidney by neutron activation analysis or X-ray fluorescence (XRF) reflect the burden, long-term exposure, and risk of toxic effect. In vivo determination by XRF of lead in fingerbone, tibia, or calcaneus reflect the long-term exposure, and should become a valuable tool in epidemiological studies, especially of chronic effects.

Body Burden↗

PubMed1978

Correlation of PCB body burden with behavioral toxicology in monkeys.

Eight monkeys fed 2.5 ppm PCB in their daily diet conceived, delivered and nursed five infants, three of which survived past weaning at four months of age. PCB residues in fat in the surviving infants at 8, 10 1/2, and 23 months of age declined linearly when plotted as log concentration versus time (first order clearance), and these functions extrapolated to presumed peak PCB levels of 21, 114, and 123 microgram/g fat (ppm) at 4 months of age. Behavioral tests on these three infants and four normal controls revealed hyperlocomotor activity at 6 and 12 months of age correlated with peak PCB body burdens. Higher peak PCB body burdens also were correlated with increased errors in five of nine learning tasks conducted between 8 and 24 months of age. Point estimates of zero-effect levels of PCB body burdens ranged around 21 ppm, although it was clear that even the monkey carrying only 21 ppm PCBs at four months of age exhibited some behavioral deficits persisting through the final testing at 24 months of age.

Animals↗

PubMed1978

Lead and cadmium in hair as an indicator of body burden in rats of different age.

The purpose of this work was to evaluate whether hair values of lead and cadmium can be used as an indicator of the body burden of these metals in different age groups. The experiments were performed on rats aged 2 and 18 weeks, which received 203Pb and 115mCd by intraperitoneal injection. The whole body retention and the retention of these radioisotopes in the hair (including the skin) was determined 7 days later. Younger animals showed a higher retention in the whole body and hair of radioactive lead and cadmium. The hair values when expressed as the percentage of the whole body retention were for 203Pb the same in young and adult rats but for 115mCd they were 2 to 3 times higher in young animals than in adults. It is concluded that lead hair values are a good indicator of the total body burden in both age groups. However, the cadmium body burden of young animals would be greatly overestimated if based on hair values only. This findings might be relevant for interpreting results of hair concentrations of lead and cadmium in children.

Aging↗

PubMed1986

Estimation of mercury body burden from dental amalgam: computer stimulation of a metabolic compartmental model.

Estimated release rates of Hg vapor from dental amalgams permitted calculation of the potential Hg body burden by employing a four-compartment model for inorganic and elemental Hg distribution. A computer program, compatible with most personal computers, simulated the cumulative and incremental distribution in each compartment and total body accumulation between 1 and 10,000 days for different daily Hg dosages. For a given Hg dose of 30 micrograms/day, metabolic compartments R1-R3 were close to equilibrium at 5, 100, and 300 days, respectively; whereas by 10,000 days, R4 closely approximated total body burden and had not yet attained equilibrium. Projected values obtained with the computer model were consistent with results obtained by another method using a standard tissue burden equation, which employed experimentally determined tissue half-lives for blood and CNS. The model predicted that continuous exposure to elemental Hg vapor, at 30 micrograms/day for 10 years, would result in a total Hg body burden of 5.9 mg, of which 4.8 mg could be contained in R4. Assuming that the Hg in R4 displayed uniform distribution throughout the body, then the brain concentration was estimated to be 68 ng/g wet weight. In contrast, if Hg in R4 reflected long-term preferential accumulation in brain and other neural tissue, then concentrations as high as 4.0 micrograms/g could be attained. However, predictions of Hg concentrations in blood and urine were well within established ranges, and were unlikely to be of utility in assessing effects of chronic low-dose Hg exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Body Burden↗

PubMed1989

Epidemiologic study on the association between body burden mercury level and idiopathic Parkinson's disease.

A case-control study was conducted among the multiethnic population of Singapore to test the hypothesis that a high level of body burden mercury is associated with an increased risk of Parkinson's disease (PD). Selected factors investigated that could contribute to the body burden of mercury included dietary fish intake, ethnic over-the-counter medications, occupational exposures and possession of dental amalgam fillings. Detailed interviews were completed in 54 cases of idiopathic PD and 95 hospital-based controls, matched for age, sex and ethnicity, between July 1985 and July 1987. After adjusting for potential confounding factors, including dietary fish intake, medications, smoking and alcohol consumption, there was clear monotonic dose-response association between PD and blood mercury levels. The odds ratios (OR) and 95% confidence intervals (CI) for the approximate subject tertiles based upon blood mercury levels were 8.5 (CI = 2.2-33.2) and 9.4 (CI = 2.5-35.9), relative to the tertile with lowest blood mercury levels (less than 5.8 ng Hg/ml). Similar associations were revealed using scalp hair and urinary mercury levels. However, only the comparisons between the highest and lowest tertiles were statistically different from unity (p less than 0.05). When the body burden mercury indicators were mutually adjusted in addition to the four confounding factors, blood and urinary mercury levels showed ORs of 21.00 and 18.65, respectively. These ORs were statistically different from unity (p less than 0.05, 2-sided test). After adjustment, scalp hair mercury was shown to be a poor predictor of PD risk.

Adult↗

PubMedDate not supplied

Estimation of the body burden of arsenic in a child fatally poisoned by arsenite weedkiller.

A three-year-old child died after ingestion of a mouthful of an estimated 44% sodium arsenite solution. Litigation was initiated based on the quality of emergency treatment at a rural hospital. An issue raised in litigation was whether the child could have survived if he had received an additional dose of BAL (dimercaprol). BAL had been sent for from a neighboring city and arrived approximately 2.0 h after admission. The first 50-mg dose of BAL could have combined with a maximum of 30 mg arsenic; a second dose could have brought the total of chelated arsenic to 60 mg. To determine the total body burden of arsenic in the child, multiple tissues were analyzed. The total body burden was estimated at 113 mg, with 100 mg of this total attributable to the ingested solution. The actual body burden after two doses of BAL therefore would have been at least 40 mg, a fatal level.

Arsenic↗

PubMed1991

Lethal body burden of triphenyltin chloride in fish: preliminary results.

1. Guppies exposed to several triphenyltin chloride (TPTC) concentrations in water died as soon as a body burden of 20 +/- 10 nmol/g fish was reached. 2. Accumulation of TPTC during exposure in acute toxicity experiments can be predicted by using the kinetic parameters of TPTC. 3. The lethal body burden is two orders of magnitude lower than for narcotic organic compounds such as chlorobenzenes.

Animals↗

PubMedDate not supplied

Effect of low-level body burdens of lead on the mental development of children: limitations of meta-analysis in a review of longitudinal data.

The effect of low-level body burdens of lead on the intelligence of children, as measured by intelligence quotient (IQ), was assessed. We reviewed 35 reports from five longitudinal studies conducted in the United States and Australia. In each of these studies, infants were followed for 58 mo or less. The study populations consisted of low- and middle-socioeconomic-class infants who had low-level exposure to environmental lead. Blood-lead levels were measured in a standard fashion at various times, beginning in the prenatal period, and intelligence was first measured at 6 mo of age and was followed by subsequent assessments. Studies were assessed for quality by a review panel blinded to the identity of the investigators and their affiliations. Efforts were made to pool the data with meta-analytic techniques, but efforts were unsuccessful because the methods used to analyze and report data were inconsistent. Inconsistencies were as follows: (a) there were few instances in which IQ and blood-lead levels were measured at comparable times in different studies; (b) incompatibilities existed among the studies, including differences in independent variables, data transformations, and statistical parameters reported; (c) results conflicted when measurement intervals were comparable (i.e., heterogeneity); (d) patterns of regression and correlation coefficients were inconsistent; and (e) data were insufficient to interconvert the parameters reported. Consequently, definitive conclusions regarding the effect of low-level body burdens of lead on IQ could not be determined from the longitudinal data. Examination of the weight of the evidence from this and other studies, however, suggests an adverse relationship of lead on the intelligence of children.

Bias↗

PubMed1985

Neonatal and maternal body burdens of hexachlorobenzene (HCB) in mice: gestational exposure and lactational transfer.

Hexachlorobenzene (HCB), a ubiquitous lipophilic pollutant, was readily transferred in the milk of lactating dams to their suckling neonates. Pregnant CD-1 mice were treated during gestation, and the body burdens of HCB in the neonates and the dams were determined during lactation. Also, neonates from dams treated with HCB during gestation were cross-fostered at birth to dams treated with corn oil during gestation. The body burdens of HCB were greater in the neonates exposed to HCB by lactational transfer than the neonates exposed only by gestational transfer. In many tissues, the concentration of HCB in the pups from full litter was similar to that in pups from litters reduced to two pups per litter. Lactational transfer of HCB from the dams to the pups was a major route of excretion in that 95% of HCB was depleted during 20 days of lactation. HCB depletion was similar in dams with whole litters, and those with litters reduced to two pups.

Aging↗

PubMed1992

Pharmacokinetics of ethylene in man; body burden with ethylene oxide and hydroxyethylation of hemoglobin due to endogenous and environmental ethylene.

The inhalation pharmacokinetics and the endogenous production of ethylene has been determined in healthy volunteers with respect to the formation of the carcinogen ethylene oxide. Ethylene showed a low degree of accumulation in the body determined in six subjects, the thermodynamic partition coefficient "body/air" being 0.53 +/- 0.23 (mean +/- SD) and the accumulation factor "body/air" at steady-state being 0.33 +/- 0.13 (mean +/- SD). The rate of metabolism was directly proportional to the exposure concentration. Only 2% of ethylene inhaled was metabolized to ethylene oxide, whereas 98% of ethylene was exhaled unchanged. The rate of the endogenous production of ethylene was 32 +/- 12 nmol/h (mean +/- SD), as calculated from exhalation data from 14 subjects. The resulting body burden was 0.44 +/- 0.19 nmol/kg (mean +/- SD). By analyzing published data on ethylene oxide in man its half-life was estimated to be 42 min. Using the pharmacokinetic parameters of ethylene and ethylene oxide, the body burden of ethylene oxide due to the sum of the exposure to environmental ethylene of about 15 ppb and to endogenous ethylene exposure of 0.44 nmol/kg was predicted to be 0.25 nmol/kg. In the blood of five non-smokers and one smoker the hemoglobin adduct resulting from the reaction of ethylene oxide with the N-terminal valine, N-(2-hydroxyethyl)valine, was quantified by gas chromatography/mass spectrometry. The value of 20 +/- 5 pmol/g Hb (mean +/- SD) found in the non-smokers corroborated the steady-state level of 18 +/- 3 pmol/g Hb (mean +/- SD) calculated from the pharmacokinetic approach.

Adult↗

PubMed1986

Radium-226 body burden in U miners by measurement of Rn in exhaled breath.

Uranium miners were made to inhale Rn-free medical O2 and exhale through a 5.2-1 A1 chamber before reporting to work. The chamber was sealed and isolated from the sampling circuit. An electrostatic plate collected the freshly formed Rn-decay products. The subsequent programmed alpha counting of the plate yielded a Rn concentration in the exhaled breath. Assuming that the exhaled breath represents a certain fraction of the Rn produced inside the body, the body burden of 226Ra was calculated. Standardisation of this procedure and the data collected on 310 miners are discussed. The procedure is simple and applicable for routine measurements. The miner needs to be in the laboratory for only 10 min. The system is also portable for field application. For routine use, the minimum detectable concentration is 3.87 Bq X m-3 which corresponds to a body burden of 0.26 kBq in a typical miner, if one assumes the Rn release fraction from the body as 84%. The system offers a more convenient and sensitive alternative to whole-body counting of workers for 226Ra.

Body Burden↗