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BACKGROUND Although adverse neuropsychological and neurological health effects are well known among workers with high manganese (Mn) exposures in mining, ore-processing and ferroalloy production, the risks among welders with lower exposures are less well understood. METHODS Confined space welding in construction of a new span of the San Francisco-Oakland(More)
The purpose of this investigation was to estimate excess lifetime risk of lung cancer death resulting from occupational exposure to hexavalent-chromium-containing dusts and mists. The mortality experience in a previously studied cohort of 2,357 chromate chemical production workers with 122 lung cancer deaths was analyzed with Poisson regression methods.(More)
The goal of occupational risk assessment is often to estimate excess lifetime risk for some disabling or fatal health outcome in relation to a fixed workplace exposure lasting a working lifetime. For sub-chronic or sub-clinical health effects measured as continuous variables, the benchmark dose method can be applied, but poses issues in defining impairment(More)
Welding fume contains manganese (Mn) which is known to be bio-available to and neurotoxic for the central nervous system. Although an essential metal, Mn overexposure may cause manganism, a parkinsonian syndrome. The present welder study sought to improve the clinical portrait of manganism and to determine dose-effect relationships. The welders were(More)
Experimenters in toxicology often compare the concentration-response relationship between two distinct populations using the median lethal concentration (LC50). This comparison is sometimes done by calculating the 95% confidence interval for the LC50 for each population, concluding that no significant difference exists if the two confidence intervals(More)
BACKGROUND Standardized mortality ratios (SMRs) and other measures of relative risk by themselves may not suffice as descriptors of occupational hazards for many audiences including decision-makers and those at direct risk from hazardous work. To explore other approaches, we calculated excess years of potential life lost and excess lifetime risk for both(More)
A survey of Ohio nursing homes was conducted in 2007 to examine whether injury rates were related to facility characteristics and availability of safety equipment. The median rate of injury in the 898 facilities was 5.7 injuries per 100 workers per year. Although 95% of the facilities had written resident lift-ing policies, only 22% of these were zero-lift(More)
BACKGROUND Studies have reported associations between manganese (Mn) exposures and Mn levels in blood and urine, though the suitability of these biological measures as biomarkers of exposure is not well known. METHODS We evaluated whether whole blood, plasma, and urine Mn levels reflect exposures in occupationally exposed humans. RESULTS In active(More)
BACKGROUND The mortality experience of iron and steel workers from modern plants in developing countries has not been extensively described. METHODS Mortality at two Korean iron and steel manufacturing complexes was analyzed using Poisson regression methods with both direct and indirect standardization. Work histories were linked with a national mortality(More)
OBJECTIVE The exposure-response relationship for manganese (Mn)-induced adverse nervous system effects is not well described. Symptoms and neuropsychological deficits associated with early manganism were previously reported for welders constructing bridge piers during 2003 to 2004. A reanalysis using improved exposure, work history information, and diverse(More)