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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↗
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↗
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↗
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↗
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↗
PubMed1991

Influence of survival time on the lethal body burden of 2,3,4,5-tetrachloroaniline in the guppy, Poecilia reticulata.

The lethal body burden (LBB) of 2,3,4,5-tetrachloroaniline in guppy (Poecilia reticulata), exposed for up to 14 days, has been determined at different aqueous concentrations of the test compound. It was found that the LBB is not constant during these 14 days, declining within the first 48 h to an approximately constant value. It is concluded that LBBs of organic compounds may not always be constant and may depend on survival time.

Aniline Compounds↗
PubMed1976

Mercury in hair as an indicator of total body burden.

Hair is known to concentrate mercury, and in general the concentration of mercury in hair is proportional to and many times higher than its concentration in the blood. The variation of the mercury concentration in human head hair was used to follow the history of poisoning in people who ingested grain treated with methylmercury. Instrumental neutron activation analysis was used for mercury determination. The initial rising slope of mercury concentration along the hair was proportional to the daily intake of methylmercury per kg of body weight. The ratio of the concentration of methylmercury in human head hair to the average body concentration was found to be about 137. By using this ratio and measuring mercury concentration in hair, the total body burden can be calculated. In the patients studied, the peak body burden ranged from 0.8 to 4.4 mg/kg in cases showing mild symptoms, from 1.5 to 6 mg/kg in cases with moderate symptoms, and from 3 to 12 mg/kg in cases with severe symptoms. The curve of the variation in mercury concentrations along the hair was also used to calculate the biological half-life of methylmercury in man. Forty-eight cases were studied and it was found that the frequency curve (population distribution curve) was grouped into two distinct regions. In about 90% of the population the biological half-life of methylmercury was 35-100 days, and 10% showed high values of 110-120 days.

Adolescent↗
PubMed1992

Trace metal accumulation by the shrew Sorex araneus. I. Total body burden, growth, and mortality.

A laboratory feeding trial is described in which a known trace metal accumulator, the shrew Sorex araneus, was presented with an artificial diet containing high levels of copper and cadmium. Methodological difficulties relating to feeding trials on first generation offspring of insectivorous small mammals caught in the wild are described. There was no relationship between copper or cadmium intake and mortality during the trials. Sex differences in growth were apparently not influenced by metal intake. At the end of the trials there was a significant negative correlation between body weight and total cadmium burden. Whole body concentrations and burdens of cadmium increased with estimated intake. There was a significant negative correlation between percentage of cadmium retained as body burden and estimated cadmium intake. There was no discernible relationship between copper burden and intake.

Animals↗
PubMed1990

Renal effects of cadmium body burden of the general population.

In a cross-sectional population study to assess whether environmental exposure to cadmium is associated with renal dysfunction, 1699 subjects aged 20-80 years were studied as a random sample of four areas of Belgium with varying degrees of cadmium pollution. After standardisation for several possible confounding factors, five variables (urinary excretion of retinol-binding protein, N-acetyl-beta-glucosaminidase, beta 2-microglobulin, aminoacids, and calcium) were significantly associated with the urinary excretion of cadmium (as a marker of cadmium body burden), suggesting the presence of tubular dysfunction. There was a 10% probability of values of these variables being abnormal when cadmium excretion exceeded 2-4 micrograms/24 h. Excretion reached this threshold in 10% of non-smokers. There was also evidence that diabetic patients may be more susceptible to the toxic effect of cadmium on the renal proximal tubule.

Acetylglucosaminidase↗
PubMed1992

Side-effects: mercury contribution to body burden from dental amalgam.

The purpose of this paper is to examine and report on studies that relate mercury levels in human tissues to the presence of dental amalgams, giving special attention to autopsy studies. Until recently, there have been few published studies examining the relationship between dental amalgams and tissue mercury levels. Improved and highly sensitive tissue analysis techniques have made it possible to measure elements in the concentration range of parts per billion. The fact that mercury can be absorbed and reach toxic levels in human tissues makes any and all exposure to that element of scientific interest. Dental amalgams have long been believed to be of little significance as contributors to the overall body burden of mercury, because the elemental form of mercury is rapidly consumed in the setting reaction of the restoration. Studies showing measurable elemental mercury vapor release from dental amalgams have raised renewed concern about amalgam safety. Mercury vapor absorption occurs through the lungs, with about 80% of the inhaled vapor being absorbed by the lungs and rapidly entering the bloodstream. Following distribution by blood circulation, mercury can enter and remain in certain tissues for longer periods of time, since the half-life of excretion is prolonged. Two of the primary target organs of concern are the central nervous system and kidneys.

Alzheimer Disease↗
PubMed1975

Body burden of hexachlorbenzene in suckling rats and its effects on various organs and on liver porphyrin accumulation.

The hexachlorobenzene (HCB) and porphyrin accumulation in the ograns of 18-day-old Wistar rats, whose mothers were fed a diet containing 80 ppm HCB, were studied. Among the organs examined, the highest HCB residue was in the liver larger than kidney larger than or equal to lung larger than brain larger than spleen larger than heart. The porphyrin level in the liver of the HCB-treated. On the contrary, the weights of the kidney, brain, spleen and heart were significantly reduced. Sex did not influence the organ weight except that of the brain. The results suggested that accumulation of HCB in different organs and porphyrin in the liver of suckling Wistar rats was about equal for the males and females.

Animals↗