Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Body Burden”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 127 records · Page 7Linked to original sources
PubMed2006

Body burdens of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls and their relations to estrogen metabolism in pregnant women.

Polychlorinated dibenzo-p-dioxins (PCDDs, dioxins), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) are environmental endocrine disruptors that have half-lives of 7-10 years in the human body and have toxicities that probably include carcinogenesis. A high ratio of 4-hydroxyl estradiol (4-OH-E2) to 2-hydroxyl estradiol (2-OH-E2) has been suggested as a potential biomarker for estrogen-dependent neoplasms. In this cohort study of maternal-fetal pairs, we examined the relationship of PCDD/PCDF and PCB exposure to levels of estrogen metabolites in the sera of 50 pregnant women 25-34 years of age from central Taiwan. Maternal blood was collected during the third trimester, and the placenta was collected at delivery. We measured 17 dioxin congeners, 12 dioxin-like PCBs, and 6 indicator PCBs in placenta using gas chromatography coupled with high-resolution mass spectrometry. Estrogen metabolites in maternal serum were analyzed by liquid chromatography tandem mass spectrometry. The ratio of 4-OH-E2:2-OH-E2 decreased with increasing exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (beta=-0.124, p=0.004 by the general linear regression model, R=0.4). Meanwhile, serum levels of 4-OH-E2 increased with increasing concentrations of high-chlorinated PCDFs (i.e., 1,2,3,4,6,7,8-hepta-CDF: beta=0.454, p=0.03, R=0.30). Altered estrogen catabolism might be associated with body burdens of PCDDs/PCDFs. Our study suggests that exposure to PCDDs/PCDFs significantly affects estrogen metabolism. Therefore, PCDD/PCDF exposure must be considered when using the OH-E2 ratio as a breast cancer marker.

Benzofurans↗
PubMed2001

The in vivo assessment of thorium body burden by gamma ray sepctrometry.

Thorium is used in many different industrial technologies and is widely found in nature. Internal contamination with thorium is considered as highly hazardous because of its radiological and chemical toxicities, which depend on the chemical form in which thorium appears. The assessment of the thorium body burden is then of primary importance in detecting the risks of personal contamination, and for appropriate counteractions when contamination is detected. The in vivo assessment of the thorium lung burden is commonly achieved by gamma ray spectrometry of its progeny. Three methods for the assessment of thorium in the lungs are compared. In the first method, the radionuclide examined is 208Tl, measured with a Nal(TI) detector. This simple method can be affected by systematic errors due to 220Rn exhalation and because of the assumption of equilibrium between 232Th and 228Th. The second method, based on the measurement of the gamma rays emitted by 228Ac, requires the use of high-resolution gamma spectrometry (HPGe detectors). The accuracy of the thorium quantification is better with this technique. The third method is based on the measurement of exhaled 220Rn.

Body Burden↗
PubMed1987

Body burden profiles of single and mixed solvent exposures.

The dynamics of inhaled solvents have not been studied extensively for exposure conditions involving combinations of chemical agents. An ongoing laboratory study examining psychomotor performance effects on human volunteers exposed to spray paint agents offered an opportunity to gather data on the body burden profiles produced by the inhalation of two solvents alone and in combination. Breath and blood samples were collected from 70 male and female subjects who were randomly assigned to four treatment conditions: chemical placebo, 250 ppm acetone, 200 ppm methyl ethyl ketone, or 125 ppm acetone/100 ppm methyl ethyl ketone. The exposures lasted for four hours. No interaction between the two solvents affecting uptake or elimination was noted. There were no significant differences between the uptake and elimination in males and females. The results are discussed in relation to physiological simulation modeling of the exposure.

Acetone↗
PubMed2005

Urinary thymidine dimer as a marker of total body burden of UV-inflicted DNA damage in humans.

High levels of DNA damage are induced in human skin following exposure to UV radiation. Cyclobutane thymidine dimer (T = T) is the most common of these lesions, which are enzymatically removed as oligonucleotides from DNA and further degraded before excretion in urine. Analysis of such repair products in the urine could serve as a biomarker of total body burden of UV exposure. The aim of this study was to examine the kinetics of T = T excretion following a single tanning session in a commercial solarium and to validate the method by delivering different doses. Ten individuals used the solarium for a total of 35 sessions of body tanning. Urine was collected before UV exposure and daily thereafter (up to 5 or 11 days) and T = T was analyzed using a very sensitive and quantitative (32)P-postlabeling technique combined with high-performance liquid chromatography. Following exposure, T = T levels increased dramatically and reached a peak 3 days later; afterwards, the T = T levels gradually decreased. The total amount of T = T excreted differed about 5-fold among subjects given an equal dose. A 50% excretion time was calculated using the excretion data for the first 5 days and it was found to be between 55 and 76 hours for different individuals. There was a good correlation between the amount of T = T excreted during days 1 to 5 and the delivered UV dose. Reducing exposure time to 50% lowered the amount of T = T to 47%; if half of the lamps were covered, T = T decreased to 44%. Our data show that urinary T = T could be a suitable noninvasive biomarker for UV exposure; a finding which could also be applicable to studies in children.

Adult↗
PubMed1997

Accumulated body burden and endogenous release of lead in employees of a lead smelter.

Bone lead levels for 367 active and 14 retired lead smelter workers were measured in vivo by X-ray fluorescence in May-June 1994. The bone sites of study were the tibia and calcaneus; magnitudes of concentration were used to gauge lead body burden. Whole blood lead readings from the workers generated a cumulative blood lead index (CBLI) that approximated the level of lead exposure over time. Blood lead values for 204 of the 381 workers were gathered from workers returning from a 10-month work interruption that ended in 1991; their blood level values were compared to their tibia and calcaneus lead levels. The resulting relations allowed constraints to be placed on the endogenous release of lead from bone in smelter works. Calcaneus lead levels were found to correlate strongly with those for tibia lead, and in a manner consistent with observations from other lead industry workers. Relations between bone lead concentration and CBLI demonstrated a distinctly nonlinear appearance. When the active population was divided by date of hire, a significant difference in the bone lead-CBLI slope emerged. After a correction to include the component of CBLI existing before the workers' employment at the smelter was made, this difference persisted. This implies that the transfer of lead from blood to bone in the workers has changed over time, possibly as a consequence of varying exposure conditions.

Adult↗
PubMed2001

Temperature- and parasite-induced changes in toxicity and lethal body burdens of pentachlorophenol in the freshwater clam Pisidium amnicum.

Seasonal variation in abiotic and biotic environments may modify the toxicity of organic chemicals for aquatic organisms. In present study, survival of the freshwater clam Pisidium amnicum was studied in laboratory exposures to pentachlorophenol (PCP) in April (at 5 degress C) and July (at 19 degress C). Behavioral responses, mean survival times (MSTs), and the lethal body burdens (LBBs) of PCP for uninfected clams and for clams infected by digenean trematodes were determined separately in two PCP concentrations, 100 and 300 microgram/L. Analysis of data revealed reduced behavioral activity of the clams in the PCP exposure compared to that in the control. The time needed for toxic responses was greatly affected by temperature; MSTs were 5 to 15 times longer in winter than at summer temperatures. Unexpectedly, the infected clams in summer were more tolerant to PCP than the uninfected clams. Despite the differences in survival times, the LBBs between the seasons were constant. However, in summer, the infected clams had significantly higher LBBs than the uninfected clams. The differences in survival and LBBs between the infected and uninfected clams are suggested to be caused by the high lipid contents found in parasites, which may change the internal distribution of PCP.

Animals↗
PubMed1997

Organophosphates in the zebra mussel Dreissena polymorpha: subacute exposure, body burdens, and organ concentrations.

Subacute exposures (10 d) of the freshwater mollusc Dreissena polymorpha to disulfoton (10 mg/L), thiometon (6 mg/L), and its activated oxygen analogue demeton-S-methyl (6 mg/L) corroborate earlier findings of organophosphate resistance and accumulation in the organism. Mortality occurred not before the ninth day of exposure. Mortality was induced at high ambient water concentrations and must be due to unknown specific organophosphate effects. Body burdens reached saturation levels within one week being around 40 mg/kg wet weight for thiometon and 60 mg/kg for disulfoton. Mussels dying during the tests showed lower tissue concentrations. Elimination of accumulated organophosphates was so low in the mussel, that an efficient metabolism of these compounds in the mussel was unlikely. Different organs of Dreissena previously acutely exposed (96 h) to the organophosphate thiometon (6, 12, 25, 50 mg/L) were analyzed for their thiometon content. Thiometon could be found in all organs, but were highest in the anterior part of the viscera (230 mg/kg), where it was accumulated either in the digestive gland and/or in the gonadal tissue.

Animals↗
PubMedDate not supplied

Body burdens of lead in hypertensive nephropathy.

Chronic lead exposure resulting in blood lead concentrations that exceed 1.93 mumol/l (40 micrograms/dl) or chelatable urinary lead excretion greater than 3.14 mumol (650 micrograms) per 72 h has been associated with renal disease. A previous study had found greater chelatable urine lead excretion in subjects with hypertension and renal failure than in controls with renal failure due to other causes, although mean blood lead concentrations averaged 0.92 mumol/l (19 micrograms/dl). To determine if chelatable urinary lead, blood lead, or the hematologic effect of lead (zinc protoporphyrin) were greater in hypertensive nephropathy (when hypertension precedes elevation of serum creatinine) than in other forms of mild renal failure, we compared 40 study subjects with hypertensive nephropathy to 24 controls having a similar degree of renal dysfunction due to causes other than hypertension. Lead burdens were similar in both the study and control groups as assessed by 72-h chelatable urinary lead excretion after intramuscular injection of calcium disodium EDTA (0.74 +/- 0.63 vs. 0.61 +/- 0.40 mumol per 72 h, respectively), and by blood lead (0.35 +/- 0.23 vs. 0.35 +/- 0.20 mumol/l). We conclude that subjects from a general population with hypertensive nephropathy do not have greater body burdens of lead than renal failure controls.

Aged↗
PubMed2005

Body burdens of mercury in lower Hudson River area anglers.

The Hudson River has been a federally designated Superfund site for over 20 years. Discharges of industrial waste and of treated and untreated sewage and atmospheric deposition have introduced mercury and other persistent pollutants to the Hudson River ecosystem. Despite New York and New Jersey health advisories, many local anglers and their family members continue to consume fish caught from the river. To evaluate associations between body burden of mercury and local fish consumption, we conducted a cross-sectional study of 191 anglers recruited from piers and fishing clubs. Participants were administered a questionnaire to obtain information on local fish consumption, and 65% (124 individuals) provided a blood sample used to determine mercury levels. Mercury levels ranged from below the limit of detection (0.75 ng/mL) to 24.0 ng/mL. Participants who reported eating locally caught fish had significantly higher levels of mercury (mean (M)=2.4 ng/mL, standard error (SE)=1.2) than anglers who never ate locally caught fish (M=1.3 ng/mL, SE=1.1). A positive dose-response pattern was also observed, where participants who reported eating locally caught fish more than once a week had higher mercury levels (M=2.6 ng/mL, SE=1.1) than anglers eating fish less frequently (M=2.0 ng/mL, SE=1.2) or never at all (M=1.3 ng/mL, SE=1.1). These findings indicate that consumption of fish caught from the lower Hudson River area is a route of human exposure to mercury for the angling community.

Animals↗
PubMed1999

Body burden levels of dioxin, furans, and PCBs among frequent consumers of Great Lakes sport fish. The Great Lakes Consortium.

Dioxins, furans, and polychlorinated biphenyls (PCBs) are toxic, persist in the environment, and bioaccumulate to concentrations that can be harmful to humans. Sport anglers may be exposed to these residues via consumption of contaminated Great Lakes (GL) fish. The Health Departments of five GL states, Wisconsin, Michigan, Ohio, Illinois, and Indiana, formed a consortium to study body burden levels of chemical residues in fish consumers of Lakes Michigan, Huron, and Erie. In Fall 1993, a telephone survey was administered to sport angler households to obtain fish consumption habits and demographics. A blood sample was obtained from a portion of the study subjects. One hundred serum samples were analyzed for 8 dioxin, 10 furan, and 4 coplanar PCB congeners. Multiple linear regression was conducted to assess the predictability of the following covariates: GL sport fish species, age, BMI, gender, years sport fish consumed, and lake. Of the 100 subjects, there were 58 men; 35 consumed sport fish from Lake Michigan, 29 from Lake Huron, and 36 from Lake Erie. The overall average number of GL sport fish meals consumed in the previous 12 months was 43. Lake Erie male and female consumers, on average, ate more GL sport fish, a mean of 57 and 42 meals, respectively, than men and women from the other two lake subgroups. Median total dioxin toxic equivalents (TEq), total furan TEq, and total coplanar PCB TEq were higher among all men than all women (P=0.0001). Lake trout, salmon, age, BMI, and gender were significant regression predictors of log(total coplanar PCBs). Lake trout, age, gender, and lake were significant regression predictors of log(total furans). Age was the only significant predictor of total dioxin levels.

Adult↗
PubMed1989

"Body burden" of phosphonoformic acid after topical and vaginal administration to rabbits and beagle dogs.

Trisodium phosphonoformate (PFA), an antiviral compound, was studied in two animal species, dogs and rabbits, for systemic absorption after vaginal and topical application. Antiviral agents to be possibly used against genital and skin herpes should penetrate deeply into the skin and, hopefully, should remain there as long as possible with no or little systemic uptake. In the rabbit the absolute bioavailability after vaginal and topical administration is 14% and 12%, respectively, and in the dog 34% and 3%, respectively. Because PFA has a low toxicity the body burden may be acceptable if the compound is found to be high clinical benefit.

Administration, Intravaginal↗
PubMed2001

Multicenter field trial on possible health effects of toluene. I. Toluene body burdens in workers of the rotogravure industry.

Ambient air toluene concentrations as well as corresponding individual blood toluene levels were measured under conditions of a field trial, as basis for a correlation with possible acute effects. While the results of various psycho-physiological and medical evaluations after acute (Neubert et al., 2001) and long-term toluene exposure (Gericke et al., 2001) are published in accompanying papers, this publication deals with the exposure levels and body burdens characteristic of workers in the rotogravure industry in Germany at the time of the investigation (1993-1995). Besides providing some information on the exposure at various work-areas under occupational conditions, the correlation between a time-weighted average of the ambient air concentration with the corresponding blood toluene levels is analyzed. Limitations of such an attempt and possible pitfalls are discussed. In the largest field study so far performed on toluene exposure, 12 companies of the German rotogravure industry (and a total of 1528 volunteers) participated. Altogether, complete data sets, i.e. on both ambient air as well as blood toluene levels, were obtained from 1244 male and 124 female participants of the rotogravure industry with quite different degrees of toluene exposure. Rotogravure printers and their helpers were exposed to the highest toluene concentrations in ambient air. On the day of the evaluation, of 806 male volunteers within this group (of 1261 with verified exposure in air), 35 were exposed to a time-weighted average of 100 ppm (i.e. 375 mg/m(3)) or above, and 155 of the printers to concentrations between 50 and 100 ppm. Of the remaining 455 male participants of the rotogravure factories ('non-printers and helpers'), only three were exposed to toluene concentrations above 50 ppm. Only one of the 124 women working in the rotogravure factories was exposed to an average toluene concentrations above 100 mg/m(3) (i.e. 27 ppm). In 66 of the male volunteers toluene levels in blood of >850 microg/l were measured and 14 showed levels exceeding 1700 microg/l. When attempting to predict the resulting individual blood toluene levels from measurements of ambient air concentrations under field conditions, a considerable uncertainty is to be expected. We found a correlation coefficient of the regression curve of about 0.70, with numerous outliers (and a variation of the 12 factories between 0.52 and 0.88).

Adult↗