| 31. |
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| 32. |
- Bergdahl, Ingvar A., et al.
(author)
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Lead binding to delta-aminolevulinic acid dehydratase (ALAD) in human erythrocytes
- 1997
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In: Basic and Clinical Pharmacology and Toxicology. - : Wiley. - 0901-9928. ; 81:4, s. 153-158
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Journal article (peer-reviewed)abstract
- Over 99% of the lead present in blood is usually found in erythrocytes. To investigate the nature of this selective accumulation of lead in erythrocytes, the specific binding of lead to proteins in human erythrocytes was studied using liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC-ICP-MS). The principal lead-binding protein had a mass of approximately 240 kDa, and adsorption to specific antibodies showed that protein was delta-aminolevulinic acid dehydratase (ALAD). Thus, the previous notion that lead in erythrocytes was bound primarily to haemoglobin has to be revised. Furthermore, in lead-exposed workers, the percentage of lead bound to ALAD was influenced by a common polymorphism in the ALAD gene. Specifically, in seven carriers of the ALAD2 allele, 84% of the protein-bound lead recovered was bound to ALAD compared to 81% in seven homozygotes for the ALAD1 allele whose erythrocytes were matched for blood-lead concentration. The small difference was statistically significant in Wilcoxon matched-pairs signed-rank test (P = 0.03). No ALAD allele-specific difference in ALAD-bound lead was found among 20 unexposed controls. Perhaps the difference in ALAD-bound lead can provide an explanation for the previously reported finding of higher blood-lead levels among carriers of the ALAD2 allele than among ALAD1 homozygotes in lead-exposed populations.
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| 33. |
- Bergdahl, Ingvar A
(author)
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Lead in blood. ICP-MS studies of lead in plasma, blood and erythrocyte proteins
- 1997
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Doctoral thesis (other academic/artistic)abstract
- An inductively coupled plasma mass spectrometry (ICP-MS) method for the determination of lead in blood plasma has been developed. The detection limit was below 0.1 microgram/liter, and the precision 5%. There was no significant difference between levels in plasma and serum. Studies of individuals with varying lead exposure showed that in the general population the plasma concentrations were less than 1% of the levels in blood, and up to a few percent in highly lead-exposed individuals. There was a non-linear relationship between blood- and plasma-lead concentrations. The non-linearity could be described by a model based on high-affinity erythrocyte lead-binding proteins with a limited binding capacity. The association was relatively close, with an inter-individual variation in plasma lead of 30% relative standard deviation at a given blood-lead concentration. Neither age, sex, current lead exposure, nor the polymorphism in the delta-aminolevulinic acid dehydratase (ALAD) gene affected the distribution of lead between cells and plasma. Moreover, lead-binding erythrocyte proteins were studied by gel-chromatography with ICP-MS detection. The studies showed that the protein with the highest affinity for lead was ALAD. Together with a smaller protein, with an apparent molecular mass of 45 kDa, it bound more than half of the lead in the erythrocytes. There was also a small lead-binding component; the quantity of lead bound to it its not known. Lead in erythrocytes appeared not to be bound to hemoglobin.
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| 34. |
- Bergdahl, Ingvar A, et al.
(author)
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Lung cancer and exposure to quartz and diesel exhaust in Swedish iron ore miners with concurrent exposure to radon
- 2010
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In: Occupational and Environmental Medicine. - : BMJ. - 1351-0711 .- 1470-7926. ; 67:8, s. 513-518
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Journal article (peer-reviewed)abstract
- OBJECTIVES: Studies of underground miners have documented an increased risk of lung cancer mainly linked to radon exposure but possibly influenced by other concurrent exposures. METHODS: A cohort study was carried out in 8321 iron ore miners with low exposure to radon, employed in 1923-1998 and followed up for lung cancer in 1958-2000. Historical exposures to radon, crystalline silica and diesel exhaust were assessed. Data including exposure to radon, quartz and diesel exhaust from another mine with higher exposure to radon were reanalysed. RESULTS: Miners had increased risk for lung cancer (SIR 1.48 (95% CI 1.22 to 1.78), based on 112 cases during 227,000 person-years). The increased risk could not be explained by exposure to radon or diesel exhaust but was associated with exposure to crystalline silica: SIR 0.96 (0.53 to 1.62), 1.45 (1.10 to 1.87), 1.99 (1.31 to 2.90) and 1.77 (0.92 to 3.10) in groups with exposure to 0, 0-2, 2-5 and >5 mg years/m3, respectively. Reanalysis of data from the other mine indicated that quartz was a possible confounder in the analysis of relationship between radon and lung cancer. In the highest radon exposed group, the point estimate for the RR decreased from 5.65 to 3.90 when adjusting for concurrent exposure to quartz. CONCLUSIONS: Crystalline silica, a known carcinogen, probably affects lung cancer risk in iron ore miners. The main implication of the results is for interpretation of the dose-response curve for radon and lung cancer in underground iron ore miners. Since exposure to radon and quartz is often correlated, quartz exposure can be an important confounder.
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| 35. |
- Bergdahl, Ingvar A., et al.
(author)
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Mercury in serum predicts low risk of death and myocardial infarction in Gothenburg women.
- 2013
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In: International archives of occupational and environmental health. - : Springer Science and Business Media LLC. - 1432-1246 .- 0340-0131. ; 86:1, s. 71-7
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Journal article (peer-reviewed)abstract
- Abstract Purpose Markers of mercury (Hg) exposure have shown both positive and negative associations with cardiovascular disease (CVD). We assessed the association between serum Hg (S–Hg) and risk of cardiovascular disease in a prospective population-based cohort, with attention to the roles of dental health and Wsh consumption. Methods Total mortality, as well as morbidity and mortality from acute myocardial infarction (AMI) and stroke, was followed up for 32 years in 1,391 women (initially age 38–60), in relation to S–Hg at baseline, using Cox regression models. Potential confounders (age, socioeconomic status, serum lipids, alcohol consumption, dental health, smoking, hypertension, waist-hip ratio, and diabetes) and other covariates (e.g., Wsh consumption) were also considered. Results Hazard ratios (HR) adjusted only for age showed strong inverse associations between baseline S–Hg and total mortality [highest quartile: hazard ratio (HR) 0.76; 95% conWdence interval (CI) 0.59–0.97], incident AMI (HR 0.56; CI 0.34–0.93), and fatal AMI (HR 0.31; CI 0.15–0.66). Adjustment for potential confounding factors, especially dental health, had a strong impact on the risk estimates, and after adjustment, only the reduced risk of fatal AMI remained statistically signiWcant. Conclusions There was a strong inverse association between Hg exposure and CVD. Likely, reasons are confounding with good dental health (also correlated with the number of amalgam Wllings in these age groups) and/or Wsh consumption. The results suggest potential eVects of dental health and/or Wsh consumption on CVD that deserve attention in preventive medicine.
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| 36. |
- Bergdahl, Ingvar A, et al.
(author)
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Metallmätningar hos gravida kvinnor i Västerbotten : Rapport till Miljöövervakningsenheten, Naturvårdsverketkontrakt nr 215 0305
- 2006
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Reports (other academic/artistic)abstract
- I denna studie har vi 2003-04 undersökt koncentrationerna av kvicksilver, kadmiumoch bly i blod från 96 gravida kvinnor i Västerbotten. För kvicksilver har vi ävenundersökt koncentrationen i hår. Västerbotten har tidvis haft ett betydandekvicksilvernedfall. Dessutom är fritidsfiske, inte minst i insjöar och mindrevattendrag, en vanlig hobby. Det finns därför skäl att undersöka om gravida kvinnor iVästerbotten har högre kvicksilvernivåer än i andra delar av Sverige.Drygt 40% av kvinnorna brukade äta insjöfisk och drygt en fjärdedel hade ätitinsjöfisk senaste månaden. Detta är högre andelar än vad man sett på andra orter.Dock hade endast 3 kvinnor ätit sådana arter som Livsmedelsverket rekommenderargravida att undvika. Kvicksilverkoncentrationen i blod var 0,02-3,5 (median: 0,6)μg/L. Det mesta var i organisk form (0,0-3,2; median: 0,5 μg/L). För kadmium varkoncentrationen 0,04-2,5 (median: 0,14) μg/L och för bly 4-47 (median: 9) μg/L.Kvicksilverkoncentrationen i hår var 0,05-1,0 (median: 0,19) μg/g.De kvicksilverkoncentrationer vi fann var likvärdiga eller lägre än vad som tidigareuppmätts på andra orter i Sverige. Det är alltså inte så att gravida i Västerbotten harsärskilt höga kvicksilverkoncentrationer, trots det kvicksilvernedfall som förekommitoch den relativt höga konsumtionen av insjöfisk. Bly- och kadmiumkoncentrationernaär att betrakta som låga, vilket dock inte innebär att säkerhetsmarginalen till nivåerdär effekter konstaterats är särskilt stor.
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| 37. |
- Bergdahl, Ingvar A, et al.
(author)
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Plasma-lead concentration: investigations into its usefulness for biological monitoring of occupational lead exposure.
- 2006
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In: American journal of industrial medicine. - New York : Wiley. - 0271-3586 .- 1097-0274. ; 49:2, s. 93-101
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Journal article (peer-reviewed)abstract
- BACKGROUND: The lead concentration in plasma is correlated to that in whole blood with a two to fourfold variation. It has never been investigated if this variation is inter-individual. METHODS: Lead and hemoglobin were determined in blood and plasma from 13 lead workers with a history of relatively high blood-lead concentrations, sampled three times during 1 day. The variation in the distribution of lead between cells and plasma was studied, but not the variation in the lead concentrations as such. RESULTS: Blood hemoglobin decreased with rising plasma lead (0.9-3.0 microg/L). Regarding the distribution of lead, no effect of current exposure during the day or of recent meals appeared. As much as 84% of the overall variance of the distribution of lead between cells and plasma could be attributed to individual factors. After adjustment for erythrocyte volume fraction this decreased to 67%. Plasma samples with elevated hemoglobin concentrations (due to in vitro hemolysis) had somewhat elevated lead concentrations. CONCLUSIONS: Plasma lead is not significantly altered by variation in a single day's exposure and, therefore, the choice of time of the day is not critical for sampling. However, plasma lead is negatively correlated to blood hemoglobin and mild hemolysis (not visible by the eye) in a sample may increase plasma lead with up to 30%. Finally, plasma provides lead exposure information that differs from whole blood, but it is not clear which one of these is the biomarker with the closest relation to exposure and/or effects.
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| 38. |
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| 39. |
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| 40. |
- Chen, Xiao, et al.
(author)
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Changes in bone mineral density 10 years after marked reduction of cadmium exposure in a Chinese population.
- 2009
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In: Environmental research. - : Elsevier BV. - 1096-0953 .- 0013-9351. ; 109:7, s. 874-9
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Journal article (peer-reviewed)abstract
- The main focus of this study was to evaluate the long-term effects of Cd on forearm bone mineral density after the cessation of the ingestion of Cd-polluted rice. A total of 458 persons (294 women, 164 men) from three Cd exposure areas (low, moderately, and heavy) participated in this study. Those living in the moderate and heavy exposure areas ceased ingesting Cd-polluted rice (0.51 and 3.7mg/kg, respectively) in 1996 (10 years prior to present analysis). The participants completed a questionnaire and bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DXA) at the proximal radius and ulna. The changes and change percentage in forearm bone density and the prevalence of osteoporosis between 1998 and 2006 were used as markers of bone recovery. The Cd concentrations in urine (UCd) and blood (BCd) in 1998 were used as Cd exposure markers. The values of the BMD change and change percentage of groups in which UCd was above 5microg/g creatinine (microg/g crea) and BCd was above 10microg/L were significantly higher than those of the low-exposure groups (in women, p<0.001; in men, p>0.05). The BMD change and change percentage correlated positively with the UCd and BCd (in women, p<0.01; in men, p>0.05). Analysis of the Z-score revealed that the prevalence of osteoporosis in 2006 was higher than that in 1998 and increased along with the level of UCd and BCd in both women and men, especially for those subjects with the higher BCd [BCd>5microg/L, OR=3.45 (0.95-13.6); BCd>10microg/L, OR=4.51(1.57-13.54)] and UCd [UCd>10microg/g crea, OR=4.74 (1.82-12.81)] in women. It is concluded that decreasing dietary cadmium exposure at the population level is not associated with bone recovery at the individual level, and the adverse bone effects of Cd exposure persisted after the main source of Cd exposure had been blocked, especially in women.
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