Hexavalent chromium (Cr(VI)) is a serious environmental pollutant and human toxicant. Mammalian cells are very sensitive to chromate as they lack efficient chromate detoxifying strategy, e.g., chromate-reducing genes that are widely present in prokaryotes. To test whether introduction of prokaryotic chromate-reducing gene into mammalian cells could render higher chromate resistance, an Escheric...

Key words: mineral/water interface, reduced Fe minerals, natural attenuation To address the potential for abiotic natural attenuation of chromate, we have studied the kinetics and mechanism of chromate removal in the presence of hydroxycarbonate green rust. The kinetics of chromate removal were studied in batch systems to evaluate the effect of green rust surface area and pH. The rate of chroma...

Aluminum and aluminum alloys can be protected against corrosion by various methods of surface modification (e.g., metal finishing, anodizing, chromate conversion coatings, metallic cladding with Alclad, corrosion protection compounds, and solution phase inhibitors). The desire to deploy environmentally compliant multi-functional coatings has created the need for new concepts that can protect Al...

Inhalation of soluble chromium(VI) is firmly linked with higher risks of lung cancer in humans. However, comparative studies in rats have found a high lung tumorigenicity for moderately soluble chromates but no tumors for highly soluble chromates. These major species differences remain unexplained. We investigated the impact of extracellular reducers on responses of human and rat lung epithelia...

The effects of chromate on sulfate uptake and assimilation were investigated in the accumulator Brassica juncea (L.) Czern. Seven-day-old plants were grown for 2 d under the following combination of sulfate and chromate concentration: (i) no sulfate and no chromate (-S), (ii) no sulfate and 0.2 mmol L(-1) chromate (-S +Cr), (iii) 1 mmol L(-1) sulfate and no chromate (+S), or (iv) 1 mmol L(-1) s...

Various chemicals can be added to urine specimens collected for drug analysis to abnormally elevate ionic concentrations and/or interfere with either immunoassay urine drug-screening procedures or gas chromatographic-mass spectrometric confirmation techniques. One such adulterant, "Urine Luck" (formula 5.3), has been identified in our previous research to contain potassium dichromate. Screening...

Hexavalent chromium [Cr(VI)] compounds are established human lung carcinogens. The carcinogenicity of Cr(VI) is related to its solubility, with the most potent carcinogens being the insoluble particulate Cr(VI) compounds. However, it remains unknown why particulate Cr(VI) is more carcinogenic than soluble Cr(VI). One possible explanation is that particulates may provide more chronic exposures t...

The chromate resistance determinant of Pseudomonas aeruginosa plasmid pUM505 was cloned into broad-host-range vector pSUP104. The hybrid plasmid containing an 11.1-kilobase insert conferred chromate resistance and reduced uptake of chromate in P. aeruginosa PAO1. Resistance to chromate was not expressed in Escherichia coli. Contiguous 1.6- and 6.3-kilobase HindIII fragments from this plasmid hy...

S INCE THE INITIAL work of Gray and Sterling,”2 the determination of red cell mass with radioactive sodium chromate has undergone several modifications. Read’ developed the technic of adding ascorbic acid in vitro to the blood-sodium chromate mixture to reduce chromate to trivalent chromium and prevent further uptake by red cells. The inhibition of chromium uptake by ascorbic acid supported the...