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Aliso Viejo, CA, United States

Madl A.K.,Chemical Risk. LLC | Unice K.,Chemical Risk. LLC | Kreider M.,Chemical Risk. LLC | Kovochich M.,Chemical Risk. LLC | And 2 more authors.
Technical Proceedings of the 2013 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2013 | Year: 2013

The unique combination of size, structure, morphology, and physical/chemical characteristics of nanomaterials presents challenges to understanding the potential hazards and health risks of engineered nanomaterials. A hierarchical risk ranking framework was developed for two nanomaterials, carbon black and carbon nanotubes, as a case study for industrial and consumer use settings. A numerical risk ranking scheme was derived from product and nanomaterial characteristics, use and exposure patterns, and toxicological information. Primary drivers of risk ranking estimates included releasability from the matrix or system, exposure pathway and intensity, bioavailability, biopersistence and severity of health effects. Evident differences in hazard ranking were observed between nanostructured materials of similar elemental composition but different morphologies. This framework offers a novel strategy to identify and prioritize the hazard and potential health risks of nanomaterials and associated products throughout their lifecycle.

Unice K.M.,Chemical Risk. LLC | Monnot A.D.,Chemical Risk. LLC | Gaffney S.H.,Chemical Risk. LLC | Tvermoes B.E.,Chemical Risk. LLC | And 3 more authors.
Food and Chemical Toxicology | Year: 2012

Soluble cobalt (Co) supplements with recommended daily doses up to 1000 μg Co/day are increasingly being marketed to consumers interested in healthy living practices. For example, some athletes may consider using Co supplements as blood doping agents, as Co is known to stimulate erythropoesis. However, the distribution and excretion kinetics of ingested Co are understood in a limited fashion. We used a Co-specific biokinetic model to estimate whole blood and urine Co levels resulting from oral exposure or ingestion of Co in amounts exceeding typical dietary intake rates. Following 10. days of Co supplementation at a rate of 400 to 1000 μg/day, predicted adult Co concentrations range from 1.7 to 10 μg/L in whole blood, and from 20 to 120 μg/L in urine. Chronic supplementation (≥1. year) at a rate of 1000 μg Co/day is predicted to result in blood levels of 5.7 to 13 μg/L, and in urine levels from 65 to 150 μg/L. The model predictions are within those measured in humans following ingestion of known doses. The methodology presented in this paper can be used to predict urinary or blood Co levels following acute or chronic occupational incidental ingestion, medicinal therapy, supplemental intake, or other non-occupational exposures. © 2012 Elsevier Ltd.

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