Bioaccessibility of Metallic Nickel and Nickel Oxide Nanoparticles in Four Simulated Biological Fluids.

Bioaccessibility of metals from substances and alloys is increasingly used as part of the assessment to predict potential toxicity. However, data are sparse on the metal bioaccessibility from nanoparticle (NP) size metal substances. This study examines nickel ion release from metallic nickel and nickel oxide micron particles (MPs) and NPs in simulated biological fluids at various timepoints including those relevant for specific routes of exposure.

Bioaccessibility of nickel and cobalt in synthetic gastric and lung fluids and its potential use in alloy classification.

This study investigated nickel and cobalt ion release from the metals and several alloys in synthetic gastric, as well as interstitial and lysosomal lung fluids. Results were used to calculate the relative bioaccessible concentrations (RBCs) of the metals. Nickel release from SS 316L powder in gastric fluid was >300-fold lower than from a simple mixture of powders of the same bulk composition.

Toxicity of sodium tungstate to earthworm, oat, radish, and lettuce.

Due to unknown effects of the potential exposure of the terrestrial environment to tungsten substances, a series of toxicity studies of sodium tungstate (Na(2) WO(4) ) was conducted. The effect on earthworm (Eisenia fetida) survival and reproduction was examined using Organisation for Economic Co-operation and Development (OECD) Guideline 222. No effect on either endpoint was seen at the highest concentration tested, resulting in a 56-d no-observed-effect concentration (NOEC) of ≥586 mg tungsten/kg dry soil (nominal concentrations).

Children's clothing fasteners as a potential source of exposure to releasable nickel ions.

Background: Cutaneous nickel allergy in the very young is not well documented or characterized. A significant number of individuals are nickel sensitized by their mid-teenage years. Recent studies suggest that children may become sensitized to nickel at an early age.

Oral carcinogenicity study with nickel sulfate hexahydrate in Fischer 344 rats.

Until now, existing data on the oral carcinogenicity of nickel substances have been inconclusive. Yet, the assessment of oral carcinogenicity of nickel has serious scientific and regulatory implications. In the present study, nickel sulfate hexahydrate was administered daily to Fischer 344 rats by oral gavage for 2 years (104 weeks) at exposure levels of 10, 30 and 50 mg NiSO(4).