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1.
Oxidative Stress Indices as Markers of Lead and Cadmium Exposure Toxicity in Auto Technicians in Ibadan, Nigeria.
Omotosho, IO
Oxidative medicine and cellular longevity. 2019;:3030614
Abstract
Auto technicians (auto mechanics, panel beaters, battery chargers, and auto painters) are among the most valuable work force in the society. Reports on oxidative stress in persons occupationally exposed to mixed chemicals abound; however, few have narrowed down specifically on auto technicians, while even fewer have stratified the exposure in the different subgroups of auto technicians. This study evaluated the antioxidant status in auto technicians routinely exposed to lead and cadmium and stratified the results of exposure by different subgroups of auto technicians in Ibadan, Nigeria. Sixty-five apparently healthy males (aged 18 to 65years) were selected based on specific inclusion criteria using a structured questionnaire. Thirty-four were cases consisting of participants routinely working as auto technicians or apprentices(≥2years) while controls were thirty-one nonoccupationally exposed male members of staff/students of the University College Hospital, Ibadan, Nigeria. Blood was collected from all participants and analyzed for the presence of lead, total antioxidant capacity (TAC), and total plasma peroxides (TPP); oxidative stress index (OSI) was calculated. Urine samples collected from all participants were analyzed for the presence of urinary lead and cadmium using standard laboratory methods. Although values of TAC in cases (22538 ± 8726.54) were not statistically different from what was obtained in controls (26741.87 ± 8696.68), TPP and OSI were statistically higher in cases than in controls (183.88 ± 53.39 and 120.16 ± 70.54, respectively, and 0.93 ± 0.45 and 0.49 ± 0.33, respectively). The blood lead level in cases (10.11 ± 4.47) was significantly higher than in controls (7.72 ± 1.22) while elevated urinary lead and cadmium levels were observed in cases (0.65 ± 0.21 and 0.34 ± 0.11, respectively) compared to controls (0.52 ± 0.19 and 0.27 ± 0.10, respectively). Raised TPP and OSI levels-hallmark of active lipid peroxidation-found to be highest among panel beaters compared to others may be prognostic of membrane-damaging diseases in this subgroup of auto technicians.
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2.
The Effect of a Short-Term Exposure to Lead on the Levels of Essential Metal Ions, Selected Proteins Related to Them, and Oxidative Stress Parameters in Humans.
Dobrakowski, M, Boroń, M, Birkner, E, Kasperczyk, A, Chwalińska, E, Lisowska, G, Kasperczyk, S
Oxidative medicine and cellular longevity. 2017;:8763793
Abstract
The present study was designed to explore the possible influence of subacute exposure to lead on the levels of selected essential metals, selected proteins related to them, and oxidative stress parameters in occupationally exposed workers. The study population included 36 males occupationally exposed to lead for 36 to 44 days. Their blood lead level at the beginning of the study was 10.7 ± 7.67 μg/dl and increased to the level of 49.1 ± 14.1 μg/dl at the end of the study. The levels of calcium, magnesium, and zinc increased significantly after lead exposure compared to baseline by 3%, 3%, and 8%, respectively, while the level of copper decreased significantly by 7%. The malondialdehyde (MDA) level and the activities of catalase (CAT) and superoxide dismutase (SOD) did not change due to lead exposure. However, the level of lipid hydroperoxides (LPH) in serum increased significantly by 46%, while the level of erythrocyte lipofuscin (LPS) decreased by 13%. The serum levels of essential metals are modified by a short-term exposure to lead in occupationally exposed workers. A short-term exposure to lead induces oxidative stress associated with elevated levels of LPH but not MDA.
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3.
Association between inflammatory marker, environmental lead exposure, and glutathione S-transferase gene.
Sirivarasai, J, Wananukul, W, Kaojarern, S, Chanprasertyothin, S, Thongmung, N, Ratanachaiwong, W, Sura, T, Sritara, P
BioMed research international. 2013;:474963
Abstract
A number of studies suggested that lead is related to the induction of oxidative stress, and alteration of immune response. In addition, modifying these toxic effects varied partly by GST polymorphism. The objectives of this study were to assess the association between the lead-induced alteration in serum hs-CRP, with GSTM1, GSTT1, and GSTP1 Val105Ile genetic variations and the health consequence from environmental lead exposure. The 924 blood samples were analyzed for blood lead, CRP, and genotyping of three genes with real-time PCR. Means of blood lead and serum hs-CRP were 5.45 μ g/dL and 2.07 mg/L. Both CRP and systolic blood pressure levels were significantly higher for individuals with blood lead in quartile 4 (6.48-24.63 μ g/dL) compared with those in quartile 1 (1.23-3.47 μ g/dL, P < 0.01). In particular, in men with blood lead >6.47 μ g/dL the adjusted odds ratio (OR) of CRP levels for individuals with GSTP1 variants allele, GSTM1 null, GSTT1 null, double-null GSTM1, and GSTT1 compared with wild-type allele was 1.46 (95% CI; 1.05-2.20), 1.32 (95% CI; 1.03-1.69), 1.65 (95% CI; 1.17-2.35), and 1.98 (95% CI; 1.47-2.55), respectively. Our findings suggested that lead exposure is associated with adverse changes in inflammatory marker and SBP. GST polymorphisms are among the genetic determinants related to lead-induced inflammatory response.
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4.
Decreased blood lead levels after calcitriol treatment in hemodialysis patients with secondary hyperparathyroidism.
Lu, KC, Wu, CC, Ma, WY, Chen, CC, Wu, HC, Chu, P
Bone. 2011;(6):1306-10
Abstract
OBJECTIVE Secondary hyperparathyroidism (SHP) is characterized by high bone turnover, which may, in turn, result in increased release of lead from bone stores. This study investigated the effects of intravenous calcitriol on blood lead (BL) levels in patients with SHP. METHODS Intravenous calcitriol therapy was administered for 16 wk to 28 patients who were on maintenance hemodialysis (HD) and had intact parathyroid hormone (iPTH) plasma levels of >300 pg/mL. Blood was drawn at baseline and every 4 wk for 16 wk to determine the levels of iPTH; bone remodeling markers, including bone-specific alkaline phosphatase (bAP) and type 5b tartrate-resistant acid phosphatase (TRAP); and BL. RESULTS Of the 28 patients, 25 responded to calcitriol therapy; they exhibited significant decrements in serum iPTH levels by the end of 4 wk of therapy and thereafter. After 16 wk of therapy, these patients had significant reductions in serum iPTH levels (p<0.01) and significant and parallel decreases in the levels of bAP (p<0.01), TRAP (p<0.01), and BL (p<0.01). Further analysis showed a significant positive correlation between the levels of BL and serum iPTH (r=0.34, p<0.01) and BL and serum TRAP (r=0.22, p<0.05). However, there was no significant correlation between the levels of BL and serum bAP. CONCLUSION Elevated levels of BL and serum bone remodeling markers, which are common features of SHP, can be effectively suppressed by calcitriol therapy. This indicates that hyperparathyroidism not only accelerates bone remodeling but may also enhance bone lead mobilization in patients on maintenance HD.
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5.
In vivo K-shell X-ray fluorescence bone lead measurements in young adults.
Ahmed, N, Osika, NA, Wilson, AM, Fleming, DE
Journal of environmental monitoring : JEM. 2005;(5):457-62
Abstract
The (109)Cd K-shell X-ray fluorescence (XRF) technique was used to measure in vivo tibia lead concentrations of 34 young adults living in the state of Vermont (USA) and the province of New Brunswick (Canada). The subjects ranged in age from 18 to 35 years, and had no known history of elevated lead exposure. Measurement parameters were varied, using the same XRF system for both populations. Tibia lead concentrations were low for both groups, with mean values of 0.7 microg lead g(-1) bone mineral (Vermont) and 0.5 microg g(-1)(New Brunswick). No individual measurement exceeded 7 microg g(-1). Mean uncertainty values obtained for the Vermont and New Brunswick subjects were 4.1 microg g(-1) and 2.6 microg g(-1), respectively. Improved measurement uncertainty in the New Brunswick group was attributed to the use of a reduced source-to-skin distance (approximately 5 mm) and a longer measurement time (3600 seconds) using a weaker radioisotope source (< or =0.42 GBq). Measurement uncertainty tended to increase with body mass index. For a given body mass index, female subjects returned a measurement uncertainty approximately 1 microg g(-1) greater than males.
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6.
IQ and blood lead from 2 to 7 years of age: are the effects in older children the residual of high blood lead concentrations in 2-year-olds?
Chen, A, Dietrich, KN, Ware, JH, Radcliffe, J, Rogan, WJ
Environmental health perspectives. 2005;(5):597-601
Abstract
Increases in peak blood lead concentrations, which occur at 18-30 months of age in the United States, are thought to result in lower IQ scores at 4-6 years of age, when IQ becomes stable and measurable. Data from a prospective study conducted in Boston suggested that blood lead concentrations at 2 years of age were more predictive of cognitive deficits in older children than were later blood lead concentrations or blood lead concentrations measured concurrently with IQ. Therefore, cross-sectional associations between blood lead and IQ in school-age children have been widely interpreted as the residual effects of higher blood lead concentrations at an earlier age or the tendency of less intelligent children to ingest more leaded dust or paint chips, rather than as a causal relationship in older children. Here we analyze data from a clinical trial in which children were treated for elevated blood lead concentrations (20-44 microg/dL) at about 2 years of age and followed until 7 years of age with serial IQ tests and measurements of blood lead. We found that cross-sectional associations increased in strength as the children became older, whereas the relation between baseline blood lead and IQ attenuated. Peak blood lead level thus does not fully account for the observed association in older children between their lower blood lead concentrations and IQ. The effect of concurrent blood level on IQ may therefore be greater than currently believed.
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7.
Blood lead changes during pregnancy and postpartum with calcium supplementation.
Gulson, BL, Mizon, KJ, Palmer, JM, Korsch, MJ, Taylor, AJ, Mahaffey, KR
Environmental health perspectives. 2004;(15):1499-507
Abstract
Pregnancy and lactation are times of physiologic stress during which bone turnover is accelerated. Previous studies have demonstrated that there is increased mobilization of lead from the maternal skeleton at this time and that calcium supplementation may have a protective effect. Ten immigrants to Australia were provided with either calcium carbonate or a complex calcium supplement (approximately 1 g/day) during pregnancy and for 6 months postpartum. Two immigrant subjects who did not conceive acted as controls. Sampling involved monthly venous blood samples throughout pregnancy and every 2 months postpartum, and quarterly environmental samples and 6-day duplicate diets. The geometric mean blood lead at the time of first sampling was 2.4 microg/dL (range, 1.4-6.5). Increases in blood lead during the third trimester, corrected for hematocrit, compared with the minimum value observed, varied from 10 to 50%, with a geometric mean of 25%. The increases generally occurred at 6-8 months gestation, in contrast with that found for a previous cohort, characterized by very low calcium intakes, where the increases occurred at 3-6 months. Large increases in blood lead concentration were found during the postpartum period compared with those during pregnancy; blood lead concentrations increased by between 30 and 95% (geometric mean 65%; n = 8) from the minimum value observed during late pregnancy. From late pregnancy through postpartum, there were significant increases in the lead isotopic ratios from the minimum value observed during late pregnancy for 3 of 8 subjects (p < 0.01). The observed changes are considered to reflect increases in mobilization of lead from the skeleton despite calcium supplementation. The identical isotopic ratios in maternal and cord blood provide further confirmation of placental transfer of lead. The extra flux released from bone during late pregnancy and postpartum varies from 50 to 380 microg lead (geometric mean, 145 microg lead) compared with 330 microg lead in the previous cohort. For subjects replete in calcium, the delay in increase in blood lead and halving of the extra flux released from bone during late pregnancy and postpartum may provide less lead exposure to the developing fetus and newly born infant. Nevertheless, as shown in several other studies on calcium relationships with bone turnover, calcium supplementation appears to provide limited benefit for lead toxicity during lactation.
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8.
Effects of iron therapy on infant blood lead levels.
Wolf, AW, Jimenez, E, Lozoff, B
The Journal of pediatrics. 2003;(6):789-95
Abstract
OBJECTIVES To determine the effects of iron therapy on blood lead levels in infants with mildly elevated lead levels and varied iron status. METHODS Infants from a community-derived sample in Costa Rica were categorized into five groups. Group 1 had iron-deficiency anemia with hemoglobin levels RESULTS After 3 months of oral iron therapy, nonanemic iron-depleted infants had the greatest decrease in lead levels, followed by nonanemic iron-deficient infants and iron-deficient infants with hemoglobin levels <120 g/L. Lead levels increased among iron-deficient infants with hemoglobin levels <120 g/L who received intramuscular iron and iron-sufficient nonanemic infants who received placebo. CONCLUSIONS Changes in lead levels corresponded closely to changes in iron status and were plausible in terms of absorption mechanisms for lead and iron. Correcting and/or preventing iron deficiency appear to be rapid and effective means of improving infant lead levels, even in nonanemic infants.
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9.
Calcium supplementation during lactation blunts erythrocyte lead levels and delta-aminolevulinic acid dehydratase zinc-reactivation in women non-exposed to lead and with marginal calcium intakes.
Pires, JB, Miekeley, N, Donangelo, CM
Toxicology. 2002;(1-3):247-55
Abstract
The purpose of this study was to evaluate the effect of calcium supplementation during lactation on changes in blood lead indices from late pregnancy to early lactation in women with low calcium intakes and low lead-exposure. Forty-seven women, non-occupationally exposed to lead and with habitually low calcium intake ( approximately 600 mg/d), participated in the study from 29 to 38 weeks of pregnancy to 7-8 weeks post-partum, non-supplemented (n=25) and supplemented (n=22) with calcium (500 mg/d) during 6 weeks after delivery. Erythrocyte lead (PbRBC) and in vitro reactivation with zinc of blood delta-aminolevulinic acid dehydratase (Zn-delta-ALAD% reactivation) were used as lead indices. In the non-supplemented group, PbRBC and Zn-delta-ALAD% reactivation increased significantly (P<0.001) from pregnancy (0.202+/-0.049 microg Pb/g protein and 18.3+/-6.0%) to lactation (0.272+/-0.070 microg Pb/g protein and 22.7+/-6.2%). No significant changes of these indices were observed in the calcium-supplemented group from pregnancy (0.203+/-0.080 microg Pb/g protein and 15.8+/-4.5%) to lactation (0.214+/-0.066 microg Pb/g protein and 16.3+/-4.1%). PbRBC levels and Zn-delta-ALAD% reactivation at lactation were lower (P<0.05) and hematocrit levels were higher (P<0.05) in the calcium-supplemented compared to the non-supplemented women. Calcium supplementation during lactation appears to blunt the lactation-induced increase in maternal blood lead and its inhibitory effect on delta-ALAD and possibly on maternal erythropoiesis.
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10.
Alteration of biochemical parameters related with exposure to lead in heavy alcohol drinkers.
Lopez, CM, Vallejo, NE, Piñeiro, AE, Uicich, R, Damin, CF, Sarchi, MI, Villaamil Lepori, EC, Roses, OE
Pharmacological research. 2002;(1):47-50
Abstract
Blood lead levels (PbB), delta-ALA dehydratase activity (ALAD) and erythrocytic protoporphyrin (EPP) values were studied in heavy wine and spirit drinkers. Results were compared in both groups and with a control group (teetotalers). Results in all cases are expressed as arithmetic means +/- SD. PbB values found in the three groups were statistically different inter se: wine group, 195 +/- 82 microg l(-1); spirits group, 159 +/- 69 microg l(-1); teetotalers, 72 +/- 43 microg l(-1). ALAD was significantly lower in the drinker groups (wine 26.9 plus minus 11.4 U l(-1)and spirits 28.3 plus minus 11.6 U l(-1))vs the control group (48.3 plus minus 13.5 U l(-1)). Differences in EPP levels in the three groups were only significant between the teetotaler and the wine drinker groups. Our findings indicate that, in heavy drinkers (more than 2 liters of wine per day), not only are lead levels increased in the blood but there are also biochemical alterations that affect the heme biosynthetic pathway, which should be taken into account in treatment for alcoholics.