Development of an inhalation unit risk factor for hexavalent chromium
| Autor: | Robert L. Sielken, Joseph T. Haney, Ciriaco Valdez-Flores, Neeraja K. Erraguntla |
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| Rok vydání: | 2014 |
| Předmět: |
Male
Risk Chromium Lung Neoplasms Air Pollutants Occupational Toxicology Risk Assessment Cohort Studies symbols.namesake chemistry.chemical_compound Risk Factors Occupational Exposure Statistics Covariate Chromates Animals Humans Medicine Poisson Distribution Poisson regression Mortality Risk factor Hexavalent chromium Lung Proportional Hazards Models Cancer Carcinogenicity Toxicity Chromate conversion coating Proportional hazards model business.industry General Medicine Hexavalent Regulatory Occupational Diseases Inhalation chemistry Chemical Industry Relative risk Cohort Linear Models Respiratory symbols Regression Analysis Female business |
| Zdroj: | Regulatory Toxicology and Pharmacology. 68:201-211 |
| ISSN: | 0273-2300 |
| Popis: | A unit risk factor (URF) was developed for hexavalent chromium (CrVI). The URF is based on excess lung cancer mortality in two key epidemiological studies of chromate production workers. The Crump et al. (2003) study concerns the Painesville, OH worker cohort, while Gibb et al. (2000) regards the Baltimore, MD cohort. A supporting assessment was also performed for a cohort from four low-dose chromate plants (Leverkusen and Uerdingen, Germany, Corpus Christi, TX, Castle Hayne, NC). For the Crump et al. (2003) study, grouped observed and expected number of lung cancer mortalities along with cumulative CrVI exposures were used to obtain the maximum likelihood estimate and asymptotic variance of the slope (β) for the linear multiplicative relative risk model using Poisson regression modeling. For the Gibb et al. (2000) study, Cox proportional hazards modeling was performed with optimal exposure lag and adjusting for the effect of covariates (e.g., smoking) to estimate β values. Life-table analyses were used to develop URFs for each of the two key studies, as well as for supporting and related studies. The two key study URFs were combined using weighting factors relevant to confidence to derive the final URF for CrVI of 2.3E-03 per μg CrVI/m3. |
| Databáze: | OpenAIRE |
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