Serum Pb Levels Research Articles

Serum and Seminal Plasma Levels of Lead and Arsenic in Cigarette Smokers and Their Relation to the Semen Parameters

Male infertility along with altered semen parameters have been related to smoking. Smoking-related elevations in serum and seminal lead (Pb) and arsenic (As) may play a role in mediating the toxic effects of smoking on seminogram. This research aims to determine whether smoking has any significant impact on Pb and As levels in the seminal plasma and serum, as well as on the various semen parameters, when compared to nonsmokers. In total, 80 adult males were included: 60 smokers and 20 age-matched nonsmokers. Based on the number of cigarettes smoked/day (CPD), the smokers were categorized into mild (1–10), moderate (11–20), and severe (> 20). The analysis of semen was conducted in accordance with the 2010 WHO laboratory manual. Using an atomic absorption spectrophotometer, Pb and As concentrations in the serum and seminal plasma of all groups were determined. Compared to nonsmokers, smokers had a significantly reduced sperm count, motility, and viability, as well as a larger percentage of aberrant forms (P = 0.001, 0.025, 0.034, 0.002 respectively). Smokers had higher Pb concentrations in their serum and seminal fluid than nonsmokers (P = 0.002, 0.001 respectively). Seminal Pb had a significant negative correlation with sperm count (P = 0.004, r = -0.320). Serum Pb levels were found to positively correlate with seminal Pb levels (P 0.001, r = 0.648), and cigarette smokers had substantially greater seminal As levels than nonsmokers (P = 0.024). Sperm viability was strongly inversely related to seminal As (P = 0.042, r = -0.264). Seminal As levels and aberrant sperm shapes were found to be significantly correlated (P = 0.001, r = 0.414). In smokers, a significant positive relationship between seminal As and seminal Pb was observed. Therefore, semen parameters could be adversely affected by smoking through high levels of Pb and As (P = 0.012, r = 0.298).

Lead Poisoning in Opium Addicts in Shahid Rajaei Hospital of Karaj, Iran

Background: Lead (Pb) is a heavy metal that can harm major organs in humans, and its high serum levels can cause poisoning. In Iran, one of the major causes of Pb poisoning is opium consumption because drug dealers combine opium with henna, a plant extract color; Pb is added to this plant for the fixation of its color. Considering that henna makes opium heavier, it costs more, and none of the users can differentiate opium from henna as their color is the same. According to the statistics of the Iranian Ministry of Health and Medical Education, 2.3% of people between the ages of 15 and 60 are drug addicted, of whom 69% to 94% have opiate addiction. Regarding these issues, it seems necessary to study the serum level of Pb in Iranian addicts. Objectives: The status of the serum Pb level and Pb poisoning symptoms among opium addicts was investigated in this study. Materials and Methods: In this study, all addicted patients were selected based on their history of using opium who were referred to the emergency department of Shahid Rajaei Hospital in Karaj (Center of Alborz province in Iran) and were evaluated between March 2016 and September 2016. Blood samples were collected from patients to measure serum Pb levels with atomic absorption by a Perkin device (USA) and evaluate basophilic stippling of red blood cells (RBCs) in a peripheral blood smear under a light microscope. The clinical signs and symptoms of patients were evaluated in several fields. They included neurological problems (including headache, memory impairment, sensory impairment, muscle weakness, seizure, and decreased consciousness), gastrointestinal (GI) problems (including constipation, nausea and vomiting, abdominal colic pain, and anorexia), and general signs and symptoms (including myalgia, fatigue, and the presence of a Pb line on the gum). Results: During the study, 75 patients with opium addiction were enrolled, including 67 (89.3%) males and 8 (10.7%) females. The mean age of patients entering the study was 52 years. Of these patients, only one case (1.3%) used opium by inhalation, and the remaining 74 cases (98.7%) had oral addiction. The mean serum Pb level among these patients was 57.7 μg/dL (the lowest and highest levels were 0.2 and 193 μg/dL, respectively). Of these 75 patients, the serum level of 15 cases (20%) was less than 15 μg/dL, and that of 60 (80%) cases was greater than 15 μg/dL. Of all the patients, the one who had the highest serum levels of Pb (193 μg/dL) went through a seizure, lost consciousness, and died. In general, GI signs and symptoms were more common among patients than any other signs and symptoms. Conclusion: The findings of this study could reveal the most common complications of Pb poisoning in addicted patients, but no relationship was found between rare complications and Pb poisoning level.

Elevated serum lead and cadmium levels associated with increased risk of dyslipidemia in children aged 6 to 9years in Shenzhen, China.

Exposure to heavy metals can influence on metabolism, but studies have not fully evaluated young children. We investigated the association between levels of serum lead (Pb), cadmium (Cd), chromium (Cr), and arsenic (As) and risk of dyslipidemia in children. A total of 4513 children aged 6 to 9years at 19 primary schools in Shenzhen were enrolled. Overall, 663 children with dyslipidemia were matched 1:1 with control by sex and age, and levels of serum Pb, Cd, Cr, and As were detected by inductively coupled plasma-mass spectrometry. Demographic characteristics and lifestyle were covariates in the logistic regression to determine the association of heavy metal levels with risk of dyslipidemia. Serum Pb and Cd levels were significantly higher in children with dyslipidemia than controls (133.08 vs. 84.19μg/L; 0.45 vs. 0.29μg/L; all P < 0.05), but this association was not found in Cr and As. We found significant upward trends for the odds ratios (ORs) of dyslipidemia associated with increasing quartiles of Pb and Cd levels (highest quartile of serum Pb OR 1.86, 95% confidence interval (CI) 1.46-2.38; Cd OR 2.51, 95% CI 1.94-3.24). Elevated serum Pb and Cd levels were associated with increased risk of dyslipidemia among children.

Serum lead levels and its association with overweight and obesity

BackgroundLead (Pb) exposure has been associated with cardiovascular diseases and metabolic syndrome, nevertheless its association with obesity, type 2 diabetes, and dyslipidemia markers has been little explored in Mexico. Therefore, we evaluated the association of serum Pb levels (Pb-S), with body mass index (BMI), fasting plasma glucose (FPG), total cholesterol (TC), and triglycerides (TG). MethodsA cross-sectional study was performed on 85 Mexican adults (57 women and 28 men). BMI was calculated, while FPG, TC, and TG were measured by the enzymatic colorimetric method. Total Pb-S levels were measured using inductively coupled plasma mass spectrometry (ICP-MS). ResultsThe study population was 20.3 ± 1.9 years old, showed an average of Pb-S of 0.0982 ± 0.068 μg dL-1, and presented a frequency of overweight (OW) and obesity (OB) of 50.5% and 18.8%, respectively. Men had higher average FPG than women (Women= 83.930 ± 5.662 vs Men= 84.953 ± 6.495; p = 0.037). When we analyzed anthropometric and clinical variables, Pb-S and frequency of OW and OB were observed to increase within the categories of Pb-S tertiles (<0.001). The averages of Pb-S were 0.051 ± 0.035 µg dL−1, 0.107 ± 0.067 µg dL−1, and 0.151 ± 0.063 µg dL−1 for individuals with normal weight (NW), OW, and OB, respectively. In addition, an analysis adjusted for age and sex shows Pb-S is positively associated with BMI (β = 2.76 ± 0.498, p = <0.001). ConclusionOur results evidence a significant association between Pb-S and the increase of BMI in Mexican adults and highlight the important health impact that may represent environmental Pb exposure.

Serum Heavy Metals Level and OS among e-ic Waste Exposed

The current study is performed in Thi-Qar Province which included a collection of whole blood samplesfrom e-ic repair workers. The survey questionnaire was used which is a standardized tool for this researchand provides for grouping and processing of data and used standardized research instruments such asquestionnaires and interviews of a larger group of subjects to get a clearer and richer examination of the datanecessary for further analysis. A total of 100 whole blood samples were taken with different ages rangedfrom 16 years up to 56 years. Other study groups were 30 subjects from non-e-waste workers. Daily worktime approximately about 6-8 hours for 1 year up to 30 years. The results showed that the percentage ofdiabetic patients among the e-waste population is only (6.5%) all of the diabetes cases were arise for workerswhose exposure exceeded 10 years. The heavy metals concentrations in the serum were measured by usingatomic absorption spectrophotometry and the levels of (Pb) were unexpected, the mean serum Pb levels(24±54 ?g/L) of non-e-waste workers was near to that of e-waste workers (24.6±34 ?g/L) at (p? 0.05),Cd results reported high concentrations in the serum workers of e-waste (35.4±53 ?g/l) compared withworkers as non-e-waste (9.3±17.2?g/l) at (p?0.05). The results of selenium showed an increase in serum Selevels in both groups, (209.4±195.5 ????????/????) for the exposed workers compares with (178.2±29.5 ????????/????) forunexposed workers. The other important aspect on which the study focused is the SOD1/catalase antioxidantsystem. As the study showed a decrease in SOD1 (15.2±2.8????????/????????) in workers of e-waste proportion incomparison to the comparison group (36.8±60????????/????????) at (p=? 0.05). Also, the catalase concentration waslower in e-waste workers (23.9±8ng/ml) more than (28.8±6????????/????????) at (p? 0.05) in non-e-waste workers.

Multiple exposure pathways of first-year university students to heavy metals in China: Serum sampling and atmospheric modeling

In this study, we collected 308 serum samples from 17 to 20 year old first-year university students who were recruited from Lanzhou University in China a few days after their enrollment to measure the serum Pb, Cd, Hg, and As levels, and specific questionnaires for age, sex, settlement and dietary structure were designed. A 3-D atmospheric transport model was used to simulate the atmospheric concentration and dry deposition across China based on gridded Pb emission inventory to examine the association between the spatial distribution of serum concentrations and environmental fates of Pb. The mean serum Pb, Cd, Hg, and As concentrations averaged over all participating young students were 21.38, 1.46, 3.86, and 4.69 μg/L, respectively. The Pb, Cd, and Hg levels in 3%, 7%, and 20% serum samples exceeded the standards. The minimum serum As and Hg concentrations and the maximum serum Pb and Cd concentrations occurred in urban areas. Seafood diet habits (P < 0.05), sex (P < 0.05), and relocation (P < 0.01) caused significant differences in serum As, Pb, and Cd concentrations. A cluster analysis was carried out to classify the exposure pathways for target contaminants. The results indicated that 4 heavy metals in the serum of volunteers from northern China could be grouped into the same category, in which significant positive correlations were found between the serum heavy metal levels and background concentrations of surface soil. However, in other provinces and metropolises, the atmospheric pollution level played a critical role involving in the inhalation exposure pathway. We demonstrated that serum Pb levels in freshman students were related to the atmospheric transport and dry deposition of Pb.

The Effect of Moringa Oleifera Leaves Powder to Level of Serum Superoxide Dismutase (SOD), Lead (Pb), Zink (Zn) and Memory Function of Rat (Rattus norvegicus) Wistar Strain Model of Autism that is Exposed by Pb

Lead exposure (Pb) may aggravate the decrease in serum SOD levels, memory function reduction and social interaction in autism. This study aims to determine the effect of Moringa oleifera on autism models of rat exposed to lead. The five groups of rat exposed to tin were studied: normal rat (C -), autistic rat (C +) and autism rats given 180 mg (T1), 360 mg (T2) or 720 mg (T3) oleifera leaves powder. Lead acetate is given through a filler tube (0.5 gr / kg) and powdered moringa leaves mixed with feed. The results showed that serum SOD levels were lower in autistic rat than normal rat and intake of Moringa olifeifera leaves powder increased serum SOD levels in autistic rats but was not seen in normal rat. The autistic rat had higher lead levels but lower zinc levels, which were not influenced by Moringa olifeira. The social interaction between rats is strongly influenced by unbidden lead with Moringa olifeira, both in normal rat and in autistic rat. Moringa oleifera will increase serum SOD levels in autistic rats but not at normal levels. Moringa olifeira does not protect significantly rat from lead causing less social interaction, nor does it lower serum Pb levels or increase Zn levels. Moringa leaves powder does not affect memory significantly.

Elevated Serum Pb, Ni, Cd, and Cr Levels and DNA Damage in Exfoliated Buccal Cells of Teenage Scavengers at a Major Electronic Waste Dumpsite in Lagos, Nigeria.

This study investigated the levels of Pb, Ni, Cd, and Cr in the blood, and DNA damage in exfoliated buccal cavity of scavenging teenagers at Alaba International electronic market, Nigeria. One hundred and ninety-nine blood samples were collected from scavenging teenagers in Alaba International market (n = 95) and the control group (n = 104). Blood Pb, Ni, Cd, and Cr concentrations were analyzed using graphite furnace atomic absorption spectrometry. Genotoxicity assessment was through exfoliated buccal cell micronucleus assay, while questionnaire was used to collect data on factors that can contribute to the blood heavy metal levels. The blood Pb of scavenging teenagers from Alaba International market varied from 2.84 to 189.44μg/L compared to the control group with a range of 0.01 to 4.21μg/L. The blood Cd (range = 0.38-12.35μg/L), Cr (range = 0.20-19.03μg/L), and Ni (range = 0.24-21.01μg/L) were higher significantly in the Alaba group compared to the control group (Cd: range = 0.00-0.96μg/L; Cr: range = 0.01-0.72μg/L; and Ni: range = 0.00-0.28μg/L). Frequencies of micronucleus, karyolysis, and pycnosis in the exfoliated buccal cells in Alaba group also increased significantly compared with the control group. Spearman correlation analyses indicated a positive correlation between the blood Pb, Ni, Cd, and Cr and induced micronucleus in the buccal exfoliated cells. Furthermore, data showed a positive correlation between Pb, Ni, Cd, and Cr and the duration of scavenging of the teenagers. However, a negative correlation was observed between educational status and Pb, Ni, Cd, and Cr. E-waste indiscriminate disposal and primitive recycling processes may be responsible for the high blood heavy metal levels, and consequently an increased DNA damage in exfoliated buccal cells in scavenging teenagers at Alaba International market. Graphical Abstract.

Association between heavy metal levels and acute ischemic stroke

BackgroundFew studies have examined the relationship between the amounts of heavy metal and stroke incidence. The aim of this study was to explore the relationship between levels of heavy metals, including Pb, Hg, As, and Cd, in patients with acute ischemic stroke (AIS).MethodsWe selected patients with first-ever AIS onset within 1 week as our study group. Healthy controls were participants without a history of stroke or chronic disease, except hypertension. The serum levels of Pb, Hg, As, and Cd in participants in the experimental and control groups were determined. All participants received a 1-g infusion of edetate calcium disodium (EDTA). Urine specimens were collected for 24 h after EDTA infusion and measured for heavy metal levels.ResultsIn total, 33 patients with AIS and 39 healthy controls were enrolled in this study. The major findings were as follows: (1) The stroke group had a significantly lower level of serum Hg (6.4 ± 4.3 μg/L vs. 9.8 ± 7.0 μg/L, P = 0.032, OR = 0.90, 95% CI = 0.81–0.99) and a lower level of urine Hg (0.7 ± 0.7 μg/L vs. 1.2 ± 0.6 μg/L, P = 0.006, OR = 0.27, 95% CI = 0.11–0.68) than the control group. (2) No significant difference in serum Pb (S-Pb), As (S-As), and Cd (S-Cd) levels and urine Pb (U-Pb), As (U-As) and Cd (U-Cd) levels was observed in either group.ConclusionsOur study found low levels of serum and urine Hg in first-ever patients with AIS, providing new evidence of dysregulated heavy metals in patients with AIS.

Association of serum lead and mercury level with cardiometabolic risk factors and liver enzymes in a nationally representative sample of adolescents: the CASPIAN-III study.

This study aims to determine the difference of serum Pb and Hg levels in adolescents with or without metabolic syndrome (MetS) and the association of serum levels of these heavy metals with cardiometabolic risk factors and liver enzymes in Iranian adolescents. The study population consisted of 320 adolescents (160 with MetS and 160 healthy controls). The relationship between serum heavy metals and cardiometabolic risk factors was assessed by linear regression. The odds ratios (OR) of having metabolic syndrome across Pb and Hg quartiles were determined by multiple logistic regression analysis. The mean (SD) of Pb and Hg concentrations were higher in adolescents with MetS than in those without it (0.83 (0.27) and 0.17 (0.01) vs. 0.65 (0.15) and 0.10 (0.08) μg/L, P = 0.01 and 0.0001, respectively). Increase in serum Pb and Hg was associated with increase in some cardiometabolic risk factors. Among boys and girls, diastolic blood pressure (DBP), fasting blood glucose, total cholesterol (TC), triglycerides (TG), and alanine aminotransaminase increased significantly across quartiles of serum Pb. Among girls, SBP, DBP, TC, and TG had a significant increase across Hg quartiles. The corresponding figure among boys was significant for SBP, DBP, and TG. Higher quartiles of Pb increased the risk of having MetS (OR 95 % CI 3.10, 2.25-4.27), the corresponding figure was 2.03, 1.75-3.16, across Hg quartiles. Our study showed significant associations between serum Pb and Hg levels with cardiometabolic risk factors in adolescents. In future surveys, the role of potential confounders should be considered more extensively. The clinical significance of these findings needs to be confirmed in longitudinal studies. By considering the origins of chronic diseases from early life, controlling environmental pollutants should be considered as a health priority for primordial or primary prevention of noncommunicable diseases.

Serum trace metal levels in Alzheimer's disease and normal control groups.

To determine whether serum trace metals are related to abnormal cognition in Alzheimer's disease (AD). We studied serum lead (Pb), cadmium (Cd), mercury (Hg), and arsenic(As) in 89 patients with AD and in 118 cognitively normal individuals. We analyzed the results of the blood tests and the food intake. Serum Pb levels correlated with word list recall (P = .039) and word list recognition (P = .037). Without age adjustment, serum Cd levels (P = .044) were significantly higher in the AD group. After stratified age adjustment, the levels of selected trace metals did not differ significantly between AD and normal individuals. Food intakes regarding selected trace metals were not significantly different between the 2 groups. In this study, serum Pb, Cd, Hg, and As levels were not directly related to abnormal cognition in AD. Serum Pb levels were significantly negatively correlated with verbal memory scores.

Anomalili Yenidoğanlarda Katalaz ve Karbonik Anhidraz Enzim Aktiviteleri ve Bazı Mineral-Ağır Metal Seviyeleri

Objective: The aim of this study is to evaluate the factors such as antioxidant condition and mineral-heavy metal level association that may play a role in development of congenital malformations. Material and Methods: Fifteen healthy neonates as control group and 15 neonates with various congenital malformations were included study. Erythrocyte cataly (CAT) which is an antioxidant enzyme, erythrocyte carbonic anydrase (CA) enzyme activities which play a important role in acid-base balance, serum copper (Cu), lead (Pb), zinc (Zn), cadmium (Cd), iron (Fe), manganese (Mn) and magnesium (Mg) were measured from venous blood samples of each subject. Results: Erythrocyte CAT enzyme activity, serum Zn and Fe levels were statistically significantly decreased (P<0.05) in the study group while serum Cu and Cd levels were statistically significantly high (P<0.05)in the study group when compared to the control group. A negative correlation between erythrocyte CA activity and serum Pb levels was found in the study group. In the control group, negative correlations were found between erythrocyte CAT activity and serum Pb levels; serum Mg and Cu levels; and serum Cd and Mn levels. In addition, in the control group a positive correlation between serum Zn and Cu levels; erythrocyte CA activity and serum Mn levels was found. Conclusion: Our results suggest that erythrocyte CAT enzyme activity and serum Cu, Zn, Fe and Cd levels may play a role in pathogenesis of congenital malformations. The oxidative stress that rise as a result of an imbalance between prooxidant and antioxidant reactions seems to be associated with congenital malformations. Further studies are needed to confirm the association of antioxidant condition and mineral-heavy metal levels in the pathogenesis of congenital malformations.

Lead Contributes to Arterial Intimal Hyperplasia Through Nuclear Factor Erythroid 2–Related Factor–Mediated Endothelial Interleukin 8 Synthesis and Subsequent Invasion of Smooth Muscle Cells

To validate the hypothesis that the toxic heavy metal lead (Pb) may be linked to cardiovascular diseases via the initiation of atherosclerosis, in vivo and in vitro studies were conducted. During the human study part of this project, serum Pb levels of healthy young women were correlated to carotid intima-media thickness. Multivariate logistic regression analyses showed that increased serum Pb levels were significantly associated with an increased intima-media thickness (P=0.01; odds ratio per SD unit, 1.6 [95% CI, 1.1 to 2.4]). In vitro, Pb induced an increase in interleukin 8 production and secretion by vascular endothelial cells. Nuclear factor erythroid 2-related factor-2 is the crucial transcription factor involved in Pb-induced upregulation of interleukin 8. Endothelial cell-secreted interleukin 8 triggered intimal invasion of smooth muscle cells and enhanced intimal thickening in an arterial organ culture model. This phenomenon was further enhanced by Pb-increased elastin synthesis of smooth muscle cells. Our data support the hypothesis that Pb is a novel, independent, and significant risk factor for intimal hyperplasia.

Aluminium and lead abnormalities in children on haemodialysis: relationship with some medications.

IntroductionThe determination of toxic elements in the biological samples of human beings is an important clinical procedure. This study was performed to investigate the prevalence of abnormal blood contents of 2 trace elements (TEs), aluminum (Al),and lead (Pb) in hemodialysis (HD) patients and to analyze their relationship with the medications, such as CaCO3, Ca acetate, 1,25-dihydroxy vit. D3, and erythropoietin (EPO), as well as hematocrit level.Material and methodsWe included 43 patients on maintenance HD and they had continued the previously mentioned medications for at least 3 months. None of the patients were on Al containing phosphate binding agents.ResultsSerum aluminum and lead levels were significantly increased than in the healthy controls, but levels of both of them were far below toxic values. Male patients had higher mean levels of lead than did females. A strong positive correlation was found between serum Al and serum Pb levels among patients (r = 0.075, p = 0.0001).The serum level of Pb was positively correlated with the serum albumin in HD patients (r = 0.45, p = 0.03). Both serum aluminium and lead levels positively correlated with the EPO dose taken by the patients (r = 0.77, p = 0.0001 and r = 0.67, p = 0.0001 respectively).ConclusionsThe blood level of trace metals of these HD patients was not related to their medications except for the EPO dose. However, caution must be exercised in interpreting this result as dose and duration of medication may play an important role. Al and Pb over load may be considered from the causes of inadequate response to epoetin therapy.

Serum lead levels in civil servicemen and public transport drivers in Makkah City, Saudi Arabia

The risk of exposure to lead varies significantly with source and exposure rates. Short-term exposure to high levels of lead can cause clinical symptoms starting from vomiting and ending with coma, even death. To describe the prevalence of occupational exposure with lead (Pb) health hazard in Makkah Al-Mukarramah city. Comparative study with geographical locations. The city of Makkah, Saudi Arabia. Eighty nine servicemen and sixty nine public transport drivers in the city of Makkah, Saudi Arabia were analysed by atomic absorption spectrophotometer. Twelve per cent of those sampled showed serum levels higher than 40 ug/dl while the mean values were 23.14 and 15.2 ug/dl in public transport drivers and civil servicemen respectively. Accumulation and dispersion rates rather than exposure time appear to be the determinant factors for serum Pb levels. Clinical history did not correlate with serum-Pb levels, except in two cases of public transport drivers.

Methodological considerations for the accurate determination of lead in human plasma and serum.

Studies which accurately measure plasma or serum lead (Pb) are needed to evaluate the 'biologically active' fraction of Pb in the circulation, and to clarify the role of plasma in the transportation of Pb between different compartments of the body. We evaluated several methodological aspects which influence the determination of Pb in plasma and serum. Generally, venous blood was obtained by different sampling methods (routine and ultraclean) from 3 subjects without history of Pb exposure. After centrifugation (800 g) for 10 min, the plasma or serum was analyzed by inductively coupled plasma-high-resolution mass spectrometry (ICP-MS). Several evaluations were conducted, including 1) comparison of an ultraclean serum collection method with a plasma collection method that used a commercial Vacutainer-type tube for trace metals (EDTA anticoagulant); 2) the effect of whole blood standing time prior to centrifugation on plasma or serum Pb concentration; and 3) comparison of a method using commercial heparinized Vacutainer tubes to an ultraclean plasma sampling method that utilized a low-Pb heparin anticoagulant. Plasma or serum iron (Fe) levels were also measured to evaluate hemolysis. The 3 subjects had whole blood Pb (blood-Pb) levels of 1.8, 2.0, and 2.7 micrograms/dl. Their corresponding ultraclean serum-Pb levels were 0.40%, 0.30%, and 0.48% of their whole blood-Pb levels, respectively. By comparison, the EDTA Vacutainer method plasma-Pb values were 1.7%, 1.5%, and 2.4% of whole blood-Pb, respectively. Whole blood standing (clotting) times of 15, 40, and 70 min before centrifugation resulted in increasing ultraclean serum-Pb levels of 0.21%, 0.81%, and 1.2% of whole blood-Pb (1.8 micrograms/dl), respectively. Whole blood standing time had no effect on plasma-Pb levels when heparin Vacutainers were used, or when a low-Pb heparin was used to obtain ultraclean plasma. However, plasma collected using the commercial heparin Vacutainer method contained consistently higher and more variable Pb levels than samples collected using the ultraclean plasma-Pb method. Hemolysis, when present, contributed significantly to both plasma-Pb and serum-Pb levels. In conclusion, plasma-Pb and serum-Pb levels are dependent upon methodologic processing techniques, including Pb contamination control, redistribution due to EDTA anticoagulant, hemolysis, and time dependency in sample processing. While true plasma-Pb and serum-Pb levels by any method have yet to be defined, these data provide a methodological basis from which to investigate variation in Pb partitioning between whole blood and plasma within individuals.