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PubMed2002

PCDDs, PCDFs, and PCBs concentrations in breast milk from two areas in Korea: body burden of mothers and implications for feeding infants.

We determined breast milk concentration of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) in 24 mothers living in Korea, and assessed the maternal body burden based on PCDDs/PCDFs and PCBs concentrations in breast milk and an infant intake rate through breast-feeding based on their concentration in breast milk. PCDDs/PCDFs and PCBs levels in breast milk from primipara mothers were found to be higher than those from multipara mothers. For total PCDDs/PCDFs TEQ level, 2,3,4,7,8-PeCDD was the predominant congener, and the proportion of 2,3,7,8-TCDD was less than 3% of total PCDDs/PCDFs TEQ level. For PCBs TEQ level, PCB-126 was the predominant congener. Maternal body burden levels of PCDDs/PCDFs and PCBs based on their concentrations in breast milk were 268-622 TEQ ng. The daily dioxin intakes of mothers were predicted to be 0.78-2.18 TEQ pg/kg/day for PCDDs/PCDFs and 0.34-0.66 TEQ pg/kg/ day for PCBs. For the first year, the body burden of an infant was predicted to be 212 TEQ ng and the daily intake of an infant was predicted to be 85 TEQ pg/kg/day, assuming the mean dioxin-related compounds concentration (27.54 TEQ pg/g fat).

Adult↗
PubMedDate not supplied

Maternal body burden of organochlorine pesticides and dioxins.

To investigate the body burden of organochlorine pesticides and dioxins in Japanese women, 125 milk samples were collected from 41 mothers in 1994, 42 in 1995, and 42 in 1996. Of the 125 samples, 82 were from primipara mothers (first delivery) and 43 were from multipara mothers (second or later delivery). By using capillary gas chromatography with electron capture detection, beta-HCH and p,p'-DDE were detected as the major chlorine pesticides in human milk. Average levels of beta-HCH and p,p'-DDE were 475 and 368 ng/g lipid, respectively, in primipara breast milk, 314 and 259 ng/g lipid in multipara breast milk, and 420 and 330 ng/g lipid in total breast milk. Dieldrin, heptachor epoxide, oxychlordane, trans-chlordane, and cis-chlordane were detected at lower average levels of 3, 4, 34, 41, and 5 ng/g lipid, respectively. By using high-resolution gas chromatography with mass spectrometric detection, dioxins were detected in all samples. Average levels of total polychlorinated dibenzo-p-dioxin (PCDD), total polychlorinated dibenzofuran (PCDF), total PCDD + PCDF, total coplanar polychlorinatedbiphenyl (CoPCB), and total dioxin were 10.0, 7.8, 17.7, 9.9, and 27.5 TEQ (toxic equivalent) pg/g lipid, respectively, in primipara breast milk; 7.0, 5.8, 12.8, 7.3, and 20.1 TEQ pg/g lipid in multipara breast milk; and 8.9, 7.1, 16.1, 8.9, and 25.0 TEQ pg/g lipid in total breast milk. In primipara breast milk, significant correlations were found among levels of beta-HCH, p,p'-DDE, total PCDD-TEQ, total PCDF-TEQ, total CoPCB-TEQ, and total TEQ except for less correlation between p,p'-DDE and total PCDF-TEQ. Levels of these analytes also significantly increased depending on mother's age, except for total Co-PCB-TEQ. For the correlation with food habit, the only positive correlation was between total PCDF-TEQs and fish intake.

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↗
PubMed2000

Relative contributions of aqueous and dietary uptake of hydrophobic chemicals to the body burden in juvenile rainbow trout.

This study assessed the relative contributions of aqueous versus dietary uptake of three hydrophobic chemicals, 1,2, 4-trichlorobenzene (1,2,4-TCB), 1,2,3,4,5-pentachlorobenzene (PeCB), and 2,2',4,4',6,6'-hexachlorobiphenyl (HCBP). Juvenile rainbow trout (Oncorhynchus mykiss) were exposed separately to chemically spiked water and food for 4 days and 12 days, respectively. Chemical concentrations were measured in the food, water, and tissues, and this allowed calculation of uptake rate constants (k(1) from water exposure, k(d) from food exposure). The k(1) values for the three test chemicals were approximately five orders of magnitude greater than the k(d) values. Using these measured uptake rate constants, a simulation model was used to predict the relative aqueous versus dietary uptake when fish were exposed simultaneously to water and food contaminated with these hydrophobic chemicals. The model predicted for all three test chemicals that the two uptake routes would contribute equally to the chemical body burden in fish whenever the food:water chemical concentration ratio was near 10(5). However, using food:water chemical concentration ratios that might be expected in nature, the model predicted that gill uptake could account for over 98% of fish body burden for both 1,2,4-TCB and PeCB uptake (log K(ow) values of 3.98 and 5.03, respectively). For HCBP (log K(ow) of 7.55), the model predicted that the dietary uptake could contribute over 85% of the body burden. Thus, depending on the actual food:water chemical concentration ratio, aqueous uptake via the gills can predominate even when the chemicals have a log K(ow) value greater than 5.0. In addition, we confirmed that dietary uptake of hydrophobic xenobiotics increases with increasing log K(ow).

Algorithms↗
PubMed1987

Animals need not be killed to reveal their body-burdens of chlorinated hydrocarbons.

The levels of persistent, lipophilic pollutants in different organs and body-fluids of birds are governed by partitioning, i.e. the levels are correlated. This implies that it may be possible to estimate the total body-burden of chlorinated hydrocarbons, without sacrificing the animals, by examining the levels in secretory fluid. This hypothesis was tested on the goosander, a fish-eating waterfowl. We found that levels of PCB and DDE in secretions from the uropyginal gland were linearly related to levels in the breast muscle. Thus, by estimating the amounts of persistent pollutants in water-repellent secretions, the total body-burden could be calculated.

Journal Article↗
PubMed2000

Chlorinated dibenzo-p-dioxins and dibenzofurans and the human immune system: 3. Plasma immunoglobulins and cytokines of workers with quantified moderately-increased body burdens.

The concentrations of immunoglobulins (IgA, IgD, IgG, IgM) and of several cytokines were measured in the plasma of volunteers with clearly, but moderately, increased body burdens of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/PCDF), using monoclonal antibodies and an enzyme-linked immuno-sorbant assay. Two groups of workers with different body burdens of PCDD/PCDF were studied: (trial I) persons with mainly 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), and (trial II) persons with mainly penta- and hexachlorinated dibenzofurans (P5CDF/H6CDF) in their blood fat. Including the reference group, 158 volunteers were investigated. A slight but statistically significant decrease was observed in the plasma concentration of IgG1 in persons exposed to TCDD, but not in persons exposed to P5CDF/H6CDF. When the data of both groups were pooled and a multi-regression analysis against international TCDD toxicity equivalencies (I-TEq, NATO/CCMS) was performed, taking several confounding factors into account, no influence of the dioxin exposure could be revealed. There were no changes in the plasma concentrations of the other immunoglobulins studied. In the same volunteers, no deviation from the reference range was found for the concentrations of the cytokines: IL-1alpha, IL-1beta, IL-6 and TNFalpha in blood plasma.

Adult↗
PubMed2005

Total body burden arising from a week's repeated dermal exposure to N,N-dimethylformamide.

BACKGROUND: Hazardous chemicals and their metabolites may accumulate in the body following repeated airborne exposures and skin contact. AIMS: To estimate the contribution of skin absorption to total body burden of N,N-dimethylformamide (DMF) across a working week in two groups with similar levels of respiratory exposure but dissimilar skin contact. METHODS: Twenty five workers in a synthetic leather (SL) factory, 20 in a copper laminate circuit board (CLCB) factory, and 20 age and sex matched non-DMF exposed subjects, were recruited. Environmental monitoring of DMF exposure via respiratory and dermal routes, as well as biological monitoring of pre-shift urinary N-methylformamide (U-NMF), were performed for five consecutive working days. RESULTS: Environmental and biological monitoring showed no detectable exposure in controls. The average airborne DMF concentration (geometric mean (GM) 3.98 ppm, geometric standard deviation (GSD) 1.91 ppm), was insignificantly lower for SL workers than for CLCB workers (GM 4.49, GSD 1.84 ppm). Dermal DMF exposure and U-NMF values, however, were significantly higher for SL workers. A significant pattern of linear accumulation was found across a five day work cycle for SL workers but not for CLCB workers. CONCLUSIONS: Dermal exposure to DMF over five consecutive days of occupational exposure can result in the accumulation of a significant DMF body burden. The long term exposure response under both repeated and intermittent conditions of substantial skin exposure is worthy of note.

Adult↗
PubMed1996

Use of the lethal body burden in the evaluation of mixture toxicity.

In many mixtures of xenobiotics in the field situation, narcosis is the predominant mechanism of toxic action. Earlier studies have found that narcotic chemicals are additive based on exposure concentration. In this study it is revealed that the narcotic chemicals 1,2- and 1,4-dichlorobenzene are additive on a lethal body burden level. This applicability of the lethal body burden in risk assessment of mixtures of unknown chemicals is discussed, and it is compared with other methods of managing mixtures of unknown chemical composition.

Analysis of Variance↗
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↗
PubMed1994

Evaluation of the critical body burden concept based on inorganic and organic mercury toxicity to rainbow trout (Oncorhynchus mykiss).

Subadult rainbow trout (Oncorhynchus mykiss) were exposed to four waterborne concentrations each of 64-426 microg/L mercuric chloride (HgCl2) and 4-34 microg/L methylmercury chloride (CH3HgCl) until death to evaluate the critical body burden concept. Mean days to death for fish exposed to the highest and lowest concentrations of HgCl2 were 1 and 58 d, and 2 and > 100 d for fish exposed to CH3HgCl. Time to death was an important factor that influenced Hg tissue concentration, and was most evident among fish that died within a few days of exposure. Critical body burdens for Hg could be difficult to establish at the tissue level because no threshold concentrations were clearly indicated among the liver, kidney, spleen, brain, muscle, and gill that were monitored in this study. A critical burden for Hg was derived on a whole body basis for Hg in its organic form. An evaluation of this and other studies suggests whole body concentrations of 10-20 mg/kg Hg could be lethal to fish. Extrapolation from other studies indicate whole body concentrations of 1-5 mg/kg Hg could have chronic effects on fish and possibly other aquatic organisms. This concept could be used to assess the toxicological significance of chemical concentrations that are monitored in feral aquatic organisms. The tissue-based approach appears to have some advantages over current assessment protocols that focus on waterborne concentrations.

Animals↗
PubMed1995

Use of lethal body burdens to indicate species differences in susceptibility to narcotic toxicants.

Lethal body burdens (LBB) for 1,2- and 1,4-dihalogenated benzenes (F, Cl or Br) are determined in rainbow trout of two age-classes. LBBs range from 0.3 to 2.4 mmol/kg. There are no significant differences between the two tested age-classes of rainbow trout. The rainbow trout data are compared to LBBs for 1,2- and 1,4-difluorobenzene in fathead minnow which range from 2.7 to 3.0 mmol/kg, and to LBBs of dichloro- and dibromobenzenes in guppy and fathead minnow [Sijm et al. 1993] which range from 2.7 to 8.0 mmol/kg. Rainbow trout are more susceptible to dihalogenated benzenes than fathead minnow. The LBB can be used as an instrument to examine the intrinsic toxicity of a chemical to a species, and to indicate the susceptibility of a species. Possible reasons for differences in susceptibility among species are discussed.

Analysis of Variance↗
PubMed1983

An increase of cadmium body burden for this century--an investigation on human tissues.

During this century cadmium production, consumption and emissions to the atmospheric, aquatic and terrestrial environment have increased dramatically. Today, as a result of systematic investigations on the concentration of cadmium in human tissues, estimates of body burdens are available from 1968 onward. We have determined the concentrations of cadmium in old pathological--anatomical specimens (61 kidneys, 53 livers) from 1897-1939 (year of death) and found average concentrations of 0.86 micrograms Cd/g renal cortex and of 1.13 micrograms Cd/g liver. In comparison with our studies on modern autopsy material (n = 207) from 1980 the average liver concentration has not altered significantly, while in the renal cortex the concentration of cadmium has increased by a factor of 47 and the body burden by a factor of 4.7.

Body Burden↗
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↗
PubMedDate not supplied

Decrease in levels and body burden of dioxins, dibenzofurans, PCBS, DDE, and HCB in blood and milk in a mother nursing twins over a thirty-eight month period.

This paper presents measured dioxin, dibenzofuran, PCB, DDE and HCB blood and milk levels and estimated body burdens in a mother who nursed twins for thirty-eight months. A total of thirteen milk samples and three blood samples were collected and analyzed. Measured PCDD and PCDF levels in milk decreased from 309 and 21 ng/kg (ppt) to 173 and 9 ng/kg, respectively, between March 1993 and September 1995. Based on the decrease in breast milk dioxin levels, we estimate that the nursing mother reduced her dioxin body burden from 310 to 96 ng dioxin toxic equivalents (TEQs), or approximately 69%. In two and one half years the level of HCB in the mother's milk decreased from 10.7 to less than 1.8 ng/g (ppb), the level of DDE decreased from 246 to 46 ng/g and the total level of non-coplanar PCBs decreased from 285 to 63 ng/g, on a lipid basis. We estimate that the twin's consumption of dioxins, dibenzofurans, and coplanar PCBs from breast feeding was approximately 115 ng TEQ per twin.

Adult↗
PubMed2003

No significant effect of iron deficiency on cadmium body burden or kidney dysfunction among women in the general population in Japan.

OBJECTIVE: To examine if iron-deficient conditions modify body burden or health effects of cadmium among women in the general population in Japan. METHODS: In 2002, 1,482 women aged 20 to 74 years in six prefectures in Japan provided informed consent to participate in this study. They offered peripheral blood and spot urine samples, and answered questionnaires on their social habits and health conditions. Never-smoking, non-pregnant and non-lactating healthy women (1,190 subjects) were selected from the volunteers. Blood samples were analyzed for serum iron, ferritin and total iron-binding capacity (TIBC) in addition to red blood cell (RBC) counts and hemoglobin (Hb) concentration as markers of anemia and iron deficiency. Urine samples were analyzed for cadmium (Cd), alpha(1)-microglobulin (alpha(1)-MG), beta(2)-microglobulin (beta(2)-MG) as markers of Cd burden and Cd-induced tubular dysfunction; the measures were expressed after being corrected for creatinine (cr) as, e.g., Cd-Ucr. RESULTS: The subjects were classified into anemic (37 women) and iron-deficient (388 women) groups separately from healthy controls (765 women), taking ferritin (<20 ng/ml) and Hb (<10 g/100 ml) as classification indicators. Strictly matched pairs (with regard to age and prefecture) were established for 36 anemic and 280 iron-deficient cases. Comparison between the cases and the matched controls showed that serum iron was lower and TIBC was higher in accordance with lower levels of ferritin and Hb in the anemic and iron-deficient groups, although the RBC count was only slightly reduced (the anemic group) or stayed essentially unchanged (the iron-deficient group). In contrast, no significant increase in Cd-Ucr, alpha(1)-MG, or beta(2)-MG was observed in either the anemic group or the iron-deficient group compared with the matched controls. Cd-Ucr in one case of clinical anemia, however, tended to be higher than the levels among women of the same age range and from the same prefecture. Her alpha(1)-MG-Ucr and beta(2)-MG-Ucr, however, remained un-elevated. CONCLUSIONS: The current level of iron deficiency among women in the general population in Japan may not induce significant increase in Cd body burden or Cd-induced tubular dysfunction.

Adult↗
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↗
PubMed2001

Zinc and cadmium body burdens in terrestrial oligochaetes: use and significance in environmental risk assessment.

Uptake and elimination kinetics of zinc and cadmium were studied in the oligochaetes Enchytraeus albidus and Eisenia fetida. Even at the highest exposure concentrations where E. fetida survived, the internal zinc concentration was still regulated to a constant level. Enchytraeus albidus could not regulate the internal zinc concentration as well, and the body burden increased after exposure to high zinc concentrations. After transfer to clean soil, the internal zinc concentration dropped back to the control level within a few weeks. For both species, internal cadmium concentrations did not reach equilibrium during the uptake experiments. The internal concentrations causing 50% reduction in cocoon production for E. fetida exposed to cadmium varied between different soil types, indicating that no fixed critical body burdens exist. For both zinc and cadmium, bioaccumulation factors decreased with increasing soil metal concentrations. Bioaccumulation factors may therefore be poor indicators of environmental risk. Their dependence on the total soil concentration makes bioaccumulation factors also unsuitable for assessing the influence of soil characteristics on the bioavailability of metals in contaminated field soils. For the same reason, uptake rate constants are probably not suited for this purpose.

Animals↗
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↗