Robert M. Park

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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)
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)
OBJECTIVES To estimate excess lifetime risk of (a) mortality from lung disease other than cancer (LDOC), and, (b) onset of radiographic silicosis, arising from occupational exposure to respirable crystalline silica dust. METHODS Data from a cohort of California diatomaceous earth mining and processing workers exposed to crystalline silica dust (mainly as(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 Associations between occupations and neurodegenerative diseases (NDD) may be discernable in death certificate data. METHODS Hypotheses generated from 1982 to 1991 study were tested in data from 22 states for the years 1992-1998. Specific occupations and exposures to pesticides, solvents, oxidative stressors, magnetic fields, and welding fumes(More)
BACKGROUND Endocrine disrupting chemicals and carcinogens, some of which may not yet have been classified as such, are present in many occupational environments and could increase breast cancer risk. Prior research has identified associations with breast cancer and work in agricultural and industrial settings. The purpose of this study was to further(More)
Exposure to manganese (Mn) is associated with neurobehavioral effects. There is disagreement on whether commonly occurring exposures in welding, ferroalloy, and other industrial processes produce neurologically significant neurobehavioral changes representing parkinsonism. A review of methodological issues in the human epidemiological literature on Mn(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)
BACKGROUND In a group of 43 confined space welders dose-effect relationships had been identified for adverse neurological/neuropsychological functional effects in relation to manganese (Mn) in blood or air (cumulative exposure index). The welders' exposure to Mn was unprotected and with poor ventilation, lasting on average 16.5 months. A follow-up(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)