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Occupational Lead Exposure (occupational + lead_exposure)

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Medical Sciences	100%

Selected Abstracts

Brain cancer mortality and potential occupational exposure to lead: Findings from the National Longitudinal Mortality Study, 1979,1989

INTERNATIONAL JOURNAL OF CANCER, Issue 5 2006
Edwin van Wijngaarden
Abstract We evaluated the association between potential occupational lead exposure and the risk of brain cancer mortality in the National Longitudinal Mortality Study (NLMS), which is a prospective census-based cohort study of mortality among the noninstitutionalized United States population (1979,1989). The present study was limited to individuals for whom occupation and industry were available (n = 317,968). Estimates of probability and intensity of lead exposure were assigned using a job-exposure matrix (JEM). Risk estimates for the impact of lead on brain cancer mortality were computed using standardized mortality ratio (SMR) and proportional hazards and Poisson regression techniques, adjusting for the effects of age, gender and several other covariates. Brain cancer mortality rates were greater among individuals in jobs potentially involving lead exposure as compared to those unexposed (age- and gender-adjusted hazard ratio (HR) = 1.5; 95% confidence interval (CI) = 0.9,2.3) with indications of an exposure,response trend (probability: low HR = 0.7 (95% CI = 0.2,2.2), medium HR = 1.4 (95% CI = 0.8,2.5), high HR = 2.2 (95% CI = 1.2,4.0); intensity: low HR = 1.2 (95% CI = 0.7,2.1), medium/high HR = 1.9 (95% CI = 1.0,3.4)). Brain cancer risk was greatest among individuals with the highest levels of probability and intensity (HR = 2.3; 95% CI = 1.3,4.2). These findings provide further support for an association between occupational lead exposure and brain cancer mortality, but need to be interpreted cautiously due to the consideration of brain cancer as one disease entity and the absence of biological measures of lead exposure. © 2006 Wiley-Liss, Inc. [source]

Plasma-lead concentration: Investigations into its usefulness for biological monitoring of occupational lead exposure

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 2 2006
Ingvar A. Bergdahl
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 µg/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. Am. J. Ind. Med. 49:93,101, 2006. © 2006 Wiley-Liss, Inc. [source]

Evaluation of a second-generation portable blood lead analyzer in an occupational setting

AMERICAN JOURNAL OF INDUSTRIAL MEDICINE, Issue 12 2007
Noel V. Stanton MS
Abstract Background A new blood lead testing instrument has qualities that make the instrument attractive for on-site testing of occupational lead exposures. This study evaluated the accuracy of the instrument when used in a manufacturing setting, and examined the impact of blood storage and shipment on results. Methods Venous blood specimens (n,=,121) were obtained and immediately analyzed on-site using the new instrument. They were then shipped to a reference laboratory and analyzed using electro-thermal atomization atomic absorption spectrometry (ETAAS), and retested using the new instrument. Results The cohort blood lead concentration averaged 40.1 µg/dl. Results obtained on the new analyzer with freshly collected blood averaged 38.7 µg/dl. The mean difference of 1.2 µg/dl on paired samples was not statistically significant. Following blood shipment and storage, results on the analyzer increased to an average of 42.4 µg/dl. The mean increase of 3.0 µg/dl on stored blood samples also failed to reach statistical significance. Under OSHA proficiency test acceptability requirements, 94% of the results had satisfactory agreement. Conclusions The new analyzer might be a useful tool for on-site monitoring of occupational lead exposures. The manufacturer's instructions should be adhered to with respect to specimen age and storage requirements. Am. J. Ind. Med. 50:1018,1024, 2007. © 2007 Wiley-Liss, Inc. [source]