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PubMed1996

Measurement by ICP-MS of lead in plasma and whole blood of lead workers and controls.

OBJECTIVES: To test a simple procedure for preparing samples for measurement of lead in blood plasma (P-Pb) and whole blood (B-Pb) by inductively coupled plasma mass spectrometry (ICP-MS), to measure P-Pb and B-Pb in lead workers and controls, and to evaluate any differences in the relation between B-Pb and P-Pb between people. METHODS: P-Pb and B-Pb were measured by ICP-MS in 43 male lead smelter workers and seven controls without occupational exposure to lead. For analysis, plasma and whole blood were diluted 1 in 4 and 1 in 9, respectively, with a diluted ammonia solution containing Triton-X 100 and EDTA. The samples were handled under routine laboratory conditions, without clean room facilities. RESULTS: P-Pb was measured with good precision (CV = 5%) even at concentrations present in the controls. Freeze storage of the samples had no effect on the results. The detection limit was 0.015 microgram/l. The P-Pb was 0.15 (range 0.1-0.3) microgram/l in controls and 1.2 (0.3-3.6) micrograms/l in lead workers, although the corresponding B-Pbs were 40 (24-59) micrograms/l and 281 (60-530) micrograms/l (1 microgram Pb/I = 4.8 nmol/l). B-Pb was closely associated with P-Pb (r = 0.90). The association was evidently non-linear; the ratio B-Pb/P-Pb decreased with increasing P-Pb. CONCLUSIONS: By means of ICP-MS and a simple dilution procedure, P-Pb may be measured accurately and with good precision down to concentrations present in controls. Contamination of blood at sampling and analysis is no major problem. With increasing P-Pb, the percentage of lead in plasma increases. In studies of lead toxicity, P-Pb should be considered as a complement to current indicators of lead exposure and risk.

Adult↗
PubMed2004

"Getting the lead out" in Hartford, Connecticut: a multifaceted lead-poisoning awareness campaign.

As part of a citywide effort to increase lead poisoning awareness within the city of Hartford, Connecticut, the Hartford Health Department implemented a multifaceted public health campaign involving several novel elements and partnerships, including the use of municipal sanitation trucks to disseminate lead-poisoning prevention messages throughout the city. To evaluate campaign reach and effectiveness, Health Department personnel collected measures of lead-poisoning knowledge, recall of campaign components, and reports of steps taken to prevent lead poisoning from 180 largely ethnic minority parents of preschool-age children. Key results were as follows: a) Recall of campaign components ranged from 21.5 to 62.6%, with newspaper advertisements and signs on buses and billboards recalled most often and a video broadcast on public-access television recalled least often. b) More than 45% of respondents reported that they took steps to prevent lead poisoning because of at least one of the campaign components, with the newspaper advertisements being the most effective component in terms of prompting lead-poisoning prevention behavior. c) Respondents' awareness was particularly low in terms of how medical personnel and procedures can and cannot detect and prevent lead poisoning in children. This campaign prompted caregivers to take steps to prevent lead poisoning and may help public health professionals in other communities to develop novel ideas through which to embark on similar initiatives.

Adult↗
PubMed1974

Lead-induced inclusion bodies: composition and probable role in lead metabolism.

Lead-induced inclusion bodies in renal tubular cells of rats have been studied in vitro after isolation by differential centrifugation. The inclusion bodies are insoluble in physiological media but may be dissolved in denaturants like 6M urea and sodium deoxycholate. They contain about 40-50 mug of lead/mg protein, but only about 10% of this is tightly bound. They also contain calcium, iron, zinc, copper, and cadmium. The protein is rich in glutamic and aspartic acids, glycine and cystine. When dissolved in 6M urea, the protein migrates as a single band on acrylamide gel electrophoresis and has a molecular weight of 27,500. It is suggested that the inclusion bodies function as an intracellular depot of nondiffusible lead. Further studies have been directed toward finding a free, unaggregated lead-containing protein fraction. Nuclear proteins from kidneys of lead-toxic rats were separated into NaCl-, Tris-, and NaOH-soluble fractions and an insoluble acidic fraction. A quantitatively small lead-containing protein was found in the 0.14M NaCl fraction. Amino acid composition, electrophoretic mobility, molecular weight, and ability to bind lead are similar to those of insoluble inclusion body protein. The possible role of this soluble lead-binding protein in the formation of nuclear inclusion bodies is at present time not certain. These studies do suggest, however, that protein-bound lead in renal tubular cells may be partitioned between insoluble and nondiffusible morphologically discrete inclusion bodies and a soluble, extractable fraction which is presumably diffusable.

Amino Acids↗
PubMed1991

Lead in the placenta, membranes, and umbilical cord in relation to pregnancy outcome in a lead-smelter community.

As part of a cohort study of the effects of chronic exposure to lead on pregnancy outcome and child development, lead concentrations in the umbilical cord and placental tissues (body and membranes) from 9 late fetal deaths, 23 preterm births, and 18 births associated with premature rupture of the amniotic membranes were compared with the lead concentrations in the tissues obtained at 22 normal births. Modest elevations in lead concentration were found in the placental body of late fetal deaths (stillbirths) and preterm births as well as in the cord tissue associated with preterm births and premature rupture of membranes. The geometric mean lead concentration in the membranes from late fetal deaths was 2.73 micrograms/g of dry tissue (95% confidence limits 0.69-10.8), which was 3.5 times higher than the mean found in normal births (0.78 micrograms/g, 95% confidence limits 0.61-1.00). The concentration in the membranes of preterm births was also significantly high, being 1.24 micrograms/G (0.91-1.67). Low correlations of membrane and antenatal blood lead concentrations suggest that other factors in addition to exposure to environmental lead may influence the amount of lead accumulated in the placental membranes.

Chemical Industry↗
PubMed2006

Cross-sectional analysis of blood lead level of entire Korean lead workers.

We analyzed blood lead (PbB) level from the 2003 health surveillance results of 13,043 lead workers from 1,217 total lead industries to evaluate lead intoxication at low level in Korea. Geometric mean of PbB was 6.08 microg/dl and 56.6% and 7.9% of total lead workers had PbB level over than 5 microg/dl and 25 microg/dl, respectively. Male showed relatively higher PbB level compared to women, but "Manufacture of Other Electronic Valves, Tubes and Electronic Components n.e.c." had more women than male in risk of low level lead exposure. While conventional high-risk industry such as "Manufacture of Accumulators" and "Other Basic Non-ferrous Metal Industries" were remained in high-risk group in lead exposure, there were high risks in other industries such as plastic, chemical and part manufacturing. Non-production tasks such as fork lift truck driving, maintenance, lab testing, and supporting function showed high blood lead level in addition to routine manufacturing processes such as smelting and soldering.

Cross-Sectional Studies↗
PubMed1999

Evaluation of postural stability in workers exposed to lead at a secondary lead smelter.

Postural sway testing was carried out on a group of 145 workers exposed to lead in a secondary lead smelter and 84 workers not exposed to lead in a hinge manufacturing plant. All workers were measured for blood lead levels (BLL) and erythrocyte zinc protoporphyrin (ZPP) concentrations at the time of testing and both a total cumulative and a time-weighted average BLL value was constructed for the lead exposed workers. The lead exposed workers mean BLL at the time of testing was 38.9 microg/dl and the non-exposed workers mean was 2.3 microg/dl. ZPP levels averaged 55.2 microg/dl for exposed workers and 18.9 microg/dl for non-exposed workers. Total cumulative BLL averaged 83476 microg/dl days for the exposed workers, with a mean time-weighted average BLL of 35.1 microg/dl. Six tests of postural stability, four two leg conditions and two single leg conditions were administered to all subjects using a force platform to produce measurements of sway for comparison purposes. The two leg conditions also manipulated the visual and proprioceptive systems. A statistically significant association was observed for sway measurements and the current BLL for all workers, but not with the current BLL of only the lead exposed workers. No statistically significant associations were present with the cumulative measures of long-term exposure. Of the six tests of sway, only the single leg conditions showed significant exposure effects. The results suggest effects of lead exposure among those with average BLL near 40.0 microg/dl, but only in the most challenging one leg conditions.

Enzyme Inhibitors↗
PubMed2003

[Associations of Bsm1 polymorphism of the vitamin D receptor gene and blood lead, zinc protoporphyrin, and physical development in 476 environmental lead-exposed children].

The associations of the Bsm1 polymorphism of vitamin D receptor gene and blood lead, zinc protoporphyrin and physical development in 476 environmental lead-exposed children were studied. After blood lead level, age, sex and education level of the patients were adjusted by analysis of covariance, the children with B allele had larger head circumference than those with bb genotype(P = 0.02). While the subjects were stratified by blood lead level and sex, the statistically significant difference in head circumference between different Bsm1 genotypes was found only in high-blood-lead subgroup and in male subgroup. No significant influence of Bsm1 polymorphism on blood lead level, zinc protoporphyrin, height and weight was found, suggesting that the Bsm1 polymorphism of VDR gene may modify the effect of lead on the skull development of children highly exposed to lead.

Body Height↗
PubMed2006

Abdominal pain due to lead-contaminated opium: a new source of inorganic lead poisoning in Iran.

Although the incidence of occupational and adult lead poisoning has declined, the problem still exists. We encountered three patients with lead poisoning in Iran, all of whom associated with presented with diffuse abdominal pain, which was at times colicky in nature, anemia, constipation, nausea, vomiting, and slightly abnormal liver biochemistries. A history of opium ingestion was present in each of these patients. None of the patients reported known occupational exposure to toxins. Diagnoses of lead poisoning were confirmed through the detection of elevated blood lead levels. The cause of lead poisoning was attributed to the ingestion of contaminated opium. Opium adulterated with lead had not been previously recognized as a source of lead poisoning in Iran. It is, therefore, pointed out that lead poisoning should be considered as a differential diagnosis for acute abdominal colic of unclear cause in patients with opium addiction.

Abdominal Pain↗
PubMed2006

[Study on effect of lead exposure to blood lead level and hearing in young offspring through gestation-rat].

OBJECTIVE: To study the effect of lead exposure to the blood lead level and the hearing in young offspring through gestation-rat. METHOD: Experiments were carried out on 42 Wistar rats, half female and half male, randomly divided into five couple groups (A, B, C, D, E). The group A, as a normal control group, was fed with a standard diet. The group B, C, D and E were fed with a standard diet, additionally with 0.03%, 0.090%, 0.27% and 0.81% lead acetate added respectively, and then fed with standard diet after birth. DPOAE, ABR and blood lead measurement were conducted on the parents rats and the neonatal offspring rats at first week and at the third week respectively. RESULT: The blood lead level of neonatal rat reported positively related with that of the parent rats (r = 0. 5817). DPOAE test result: Both parent rats and neonatal rats presented a normal cochlea feedback curve. ABR test result: The period of the group D showed a significant difference from that of the normal control group A. Reaction threshold (dBpeSPL) of the neonatal rat group cl (at the first week) and group c3 (at the third week) showed a notable difference from that of the normal control group al and a3 (c >a). CONCLUSION: The blood lead level of a fetus rat is related with the exposure degree to lead during the pregnant period of mother rat. Low level lead exposure inside uterus during pregnant period will result easily in damage on the hearing nerve center segment and hearing conduct of a fetus rat for they are very sensitive.

Animals↗
PubMedDate not supplied

Blood lead levels in patients with lead shot retained in the appendix.

Seven patients with one or two lead shots retained in the appendix were identified by radiography. For each case, two sex- and age-matched control patients without lead shot in the appendix were found. None of the 7 patients with lead shot in the appendix had blood lead levels (median 0.55 mumol/l) approaching the toxic levels, but they averaged almost twice the levels of the controls (median 0.29 mumol/l). Thus, lead shots may add to individual lead exposures, and blood lead analysis should be performed, at least when more than a few lead shots are present.

Appendix↗
PubMed1985

Mechanism of renal lead-binding protein reversal of delta-aminolevulinic acid dehydratase inhibition by lead.

The bioavailability of lead in kidney is mediated in part by binding to endogenous high-affinity cytosolic lead-binding proteins (PbBP), which are not detectable in liver. Addition of semipurified 11,500 dalton PbBP to liver delta-aminolevulinic acid dehydratase (ALAD) reaction mixtures reverses inhibition of this enzyme by lead and thus provides an explanation for the relative insensitivity of renal ALAD to lead inhibition in vivo and in vitro. This effect results in part from a marked increase in binding of 203Pb to the PbBP relative to control liver cytosol (no PbBP) as demonstrated by Sephadex G-150 gel filtration chromatography. Zinc is known to activate ALAD and is an endogenous component of the PbBP fraction (6 microM in reaction mixtures). Zinc activated hepatic and renal ALAD over a range of 1.5 to 50 microM and also reversed the IC50 lead-inhibited activity. Studies of zinc release and/or displacement from PbBP under ALAD assay conditions (37 degrees C, + glutathione, pH 6.8) were conducted utilizing Sephadex G-25 chromatography. Fifteen to twenty-five percent of the zinc in the PbBP fraction was released, and this value was not markedly influenced by addition of IC50 lead, temperature (4 degrees C) or absence of glutathione; however, zinc release was primarily dependent upon the pH of the reaction mixture. These data indicate that the PbBP fraction attenuates lead inhibition of ALAD in vitro both by chelating lead and apparently serving as a zinc donor for this enzyme under optimal conditions of the ALAD assay.

Animals↗
PubMedDate not supplied

Source contribution of lead in house dust from a lead mining waste superfund site.

The relative contribution to household dust of lead particles from a mining waste superfund site and lead-based paint is investigated. Automated individual particle analysis (IPA) based on scanning electron microscopy (SEM) and X-ray energy spectroscopy (EDX) is used to develop a classification algorithm for determining lead particle source contribution in household dust vacuum bags. On a volume basis the proportion derived from the mining waste is found to be 26%, the proportion derived from a paint source is 16%, and the proportion from soil is 37%. In 15% of the lead particles identified a specific originating source could not be determined. Using a weighting method accounting for the lead concentration per particle rather than volume the contributions were similar for mining waste and paint, 21% and 23%, respectively, but the soil contribution was reduced to 8%, and the source for 29% of the lead could not be identified. These results suggested that the contribution of waste piles to the lead present in household dust is at least as important a source as paint. There is evidence to suggest that a large percentage of lead in the soil also originated from the waste piles and the overall contribution, therefore, of the waste piles may be greater than the contribution from paint.

Air Pollution, Indoor↗
PubMedDate not supplied

Comparison of three models for predicting blood lead levels in children: episodic exposures to lead.

A threshold blood lead level in children below which no adverse effects occur has not been identified (CDC, 1991), Therefore, the traditional risk assessment method of relating dose to a reference dose (RfD) for noncancer effects is not applicable to lead. To assess whether environmental lead concentrations may result in adverse health effects, predicted blood lead levels are compared to a blood lead level of 10 micrograms/dL, the current Centers for Disease Control and Prevention level of concern. Children's blood lead levels may be predicted with one of at least three models: USEPA'S Integrated Exposure Uptake Biokinetic Model (IEUBK), and models by O'Flaherty (1993) and Carlisle and Wade (1992). This paper explores the utility of these models for predicting blood lead levels in children, and discusses areas of uncertainty associated with the use of these models in evaluating episodic exposures. It is hoped that this discussion will stimulate interest further researching exposure and health effects from episodic contact with lead contaminated media.

Child↗
PubMed1985

Multiple unipolar lead electrocardiographic monitoring during exercise in severe coronary artery disease: a comparison with bipolar lead monitoring.

A system of 21-lead electrocardiography was used to assess 21 patients with severe angina during and after exercise using on-line computerised ST segment analysis. A direct comparison was made between the results obtained from 18 unipolar precordial leads and those from bipolar leads CM5 and CC5. Treadmill exercise was performed 48 hr prior to cardiac catheterization, which revealed luminal narrowing of at least 70% in one or more major coronary arteries in all cases. In all cases the ST depression exceeded 1 mm in both CM5 and CC5 at the peak of exercise. The magnitude of ST depression was greater in the bipolar leads in 75% of cases and in the remaining 25% the greatest peak ST depression occurred in a single unipolar lead. There was no correlation between the magnitude of ST depression and the number of coronary vessels involved. Isopotential surface mapping in the anterior, lateral and inferior projections from the unipolar leads at each stage of exercise failed to show a correlation between the area or distribution of ST segment change and the number or anatomical location of the vessels involved. It was not possible to show that the multiple-lead system could differentiate the site and severity of coronary artery disease in these patients with angina. The multiple-lead system was cumbersome and time-consuming in application and therefore cannot be recommended for routine exercise testing.

Aged↗
PubMed2005

Lead isotopes in soils near five historic American lead smelters and refineries.

This survey of soil lead in the vicinity of old industrial sites examines how the stable isotope patterns vary among the sites according to the sources of the lead ore processed at each site. Lead smelters and refineries, which closed down decades ago, are the basis of this investigation. Samples were taken from near five old factory sites in Collinsville and Alton (Illinois), Ponderay (Idaho), East Chicago (Indiana) and Omaha (Nebraska). Historical records were searched for accounts of the sources of the lead. Lead concentrations were measured by atomic absorption flame spectrophotometry, and stable isotopic analysis was done by plasma ionization mass spectrometry. At every site visited, remnants of the old factories, in terms of soil lead pollution, could be found. In spite of potential complications of varying smelter feedstock sourced from mines of different geological age, it was possible to match the isotopic patterns in the soils with the documented sources of the ores. The Collinsville and Alton sites resembled Missouri lead. The Ponderay value was higher than major Bunker Hill, Idaho deposits, but closer to the minor, nearby Oreille County, Washington ores. Mostly Utah ore was used in East Chicago. The Omaha soil reflects lead from Mexico, Colorado and Montana.

Journal Article↗
PubMed2003

Comparison of the 80-lead body surface map to physician and to 12-lead electrocardiogram in detection of acute myocardial infarction.

Diagnosis of non-ST-elevation acute myocardial infarction (AMI) by a 12-lead electrocardiogram has poor sensitivity and specificity and, therefore, relies on biochemical markers of myocardial necrosis, which can only be reliably detected within 14 to 16 hours from symptom onset. The body surface map (BSM) improves AMI detection but is limited by its interpretation by inexperienced medical staff. To facilitate interpretation, an automated BSM algorithm was developed and is evaluated in this study. One hundred three patients with ischemic-type chest pain were recruited for this study from December 2001 to April 2002. A 12-lead electrocardiogram (Marquette Mac 5K) and BSM (PRIME-ECG) were recorded at initial presentation, and cardiac troponin I and/or creatine kinase-MB levels measured at 12 hours after symptom onset. The admitting physician's 12-lead electrocardiographic (ECG) interpretation, 12-lead ECG algorithm (Marquette 12 SL V233) diagnosis, and BSM algorithm diagnosis were documented for each patient. AMI, defined by elevation of troponin I to >1 microg/L and/or creatine kinase-MB to >25U/L, occurred in 53 patients. The admitting physician diagnosed 24 patients with AMI (sensitivity 45%, specificity 94%), the 12-lead ECG algorithm diagnosed 17 patients with AMI (sensitivity 32%, specificity 98%), and the BSM algorithm diagnosed 34 patients with AMI (sensitivity 64%, specificity 94%). The BSM algorithm improved the diagnostic sensitivity by 2.0 (p <0.001) and 1.4 (p = 0.002) compared with the 12-lead ECG algorithm or the admitting physician, respectively. There was no significant difference in specificity. Thus, the BSM algorithm improves detection of AMI compared with the 12-lead ECG algorithm or physician's 12-lead ECG interpretation.

Aged↗
PubMed2003

ST-deviation reconstruction in missing leads on the 12-lead ECG: applicability in studies on ST-segment resolution during thrombolysis.

Quantitative analysis of ST-segment deviations (STdev) and their resolution by treatment (STR; calculated from a combined sum of STdev in multiple leads) are used in trials on reperfusion for myocardial infarction (MI). Unreadable or unavailable electrocardiogram (ECG) leads are a common reason for exclusion, decreasing the statistical power of the trials. We developed mathematical formulas for reconstruction of immeasurable STdev based on STdev from other available leads on the 12-lead ECG. Formulas were deducted from a database of computer-assisted STdev measurements in 2 ECGs (baseline and 180 min after thrombolysis) of 1121 pts. Their accuracy was later evaluated on a second dataset of 377 pts. Acceptable fits could be derived for absent single leads, or for groups of absent limb leads (I-II-III or aVL-aVF). The intraclass correlation coefficient between real and calculated STdev was >or= 0.80 for each (0.77 for V1 in inferior MI). The correlations between STR calculated from original data and from reconstructed STdev were very strong (all intraclass correlation >or=0.97), and discordance in STR subgroup categorization occurred in <or=10% of pts in all but one of the scenarios (I-II-III substituted in 180 min ECG in inferior MI). Scenarios with multiple missing precordial leads however are not substitutable, nor are calculated STdev reliable for STR evaluation in only the lead with highest elevation in baseline. STdev reconstruction formulas can reliably be used in trials where analysis of aggregate STR is an endpoint. Reliable substitution can significantly increase the number of evaluable patients and therefore strengthen the statistical power of these trials.

Electrocardiography↗
PubMed2002

Use of a laser sheath to obtain venous access in pacemaker lead-related obstruction without extraction of the lead.

AIMS: Occlusion of the subclavian vein resulting from pacemaker leads prohibits insertion of new leads. We describe the ipsilateral insertion of a new lead without extracting the old lead using a laser sheath in a pacemaker patient with an obstructed vein. METHODS AND RESULT: A laser sheath together with an outer sheath were advanced over the malfunctioning lead just beyond the occlusion. The laser sheath was pulled back and a guide wire inserted through the outer sheath kept in position distal of the occlusion. After removal of the outer sheath a peel-away sheath was introduced and a new lead implanted next to the malfunctioning lead that was abandoned and not extracted. CONCLUSION: By avoiding using the laser along the whole length of the lead we greatly reduced the risk of the procedure but were still able to recanalize the obstructed vein. A risk of bilateral occlusion is avoided and the contralateral site saved as an entry point for future needs.

Arrhythmias, Cardiac↗