Blog #2 -Chromium

Chromium

 

• Source

Chromium is a lustrous, brittle and hard metal that appears as silver- gray. Chromium is naturally found in the earth’s crust. Chromium is mined as chromite and ore. More industrial companies who are interested in mining chromium ore are now furthering to process it into chromium metal and others. Chromium metal can be categorized into two main forms; Trivalent Chromium (Cr III) and hexavalent Chromium (Cr VI).

History:

In 1797, Nicolas-Louis Vauguelin, a French chemist produced the first pure chromium metal by treating crocoite (a chromium-containing mineral) with potassium carbonate. This process resulted in the reduction of chromic acid with carbon in a graphite crucible.

• Biotransformation

 

• Toxicokinetics
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• Carcinogenicity:  The toxicity of chromium within the cell may result from damage to cellular components during the hexavalent to trivalent chromium reduction process, by generation of free radicals, including DNA damage [ATSDR 2000]. Recent studies indicate a biological relevance of non-oxidative mechanisms in Cr(VI) carcinogenesis

 

• Mechanism of Action (if known)
• Cr (III) is poorly absorbed, the main toxicity is from Cr (VI). Cr (VI) is absorbed by the lungs and the gastrointestinal tract and sometimes to certain skin intact. When reduction of Cr (VI) occurs at a distance from the target organ serves as detoxification process. Although the biological mechanism of interaction is uncertain, the variation of toxicity is possible to be related to the ease with which Cr (VI) which can pass through cell membrane and its subsequent intracellular reduction to reactive intermediates.

 

• Target organ(s):
  • Gastrointestinal effects
  • Cardiovascular effect: cardiopulmonary arrest via early hypoxia changes in the myocardium
  • Hepatic effect: derangement of the liver, necrosis, lymphocytic and histocytic infiltration and increase in kupffer cells.
  • Renal effect: injury to the brush border membrane of the proximal convoluted tubules.

 

• Signs and symptoms of toxicity
  • sinusitis, nasal septum perforation,
  • allergic and irritant dermatitis, skin ulcers,
  • respiratory irritation, bronchitis, asthma, and
  • lung cancer
  • circulatory collapse
  • coma, and even death, depending on the dose

 

• Treatments
  • There is no proven antidote available for chromium poisoning
  • Usually supportive and symptomatic treatment is used in cases of acute high-level chromium exposure
  • Treatment normally involves the removal of the patient from any further chromium exposure, reliance on the body’s naturally rapid clearance of the metal and symptomatic management
  • Physician can provide advice and patient education regarding smoking cessation and how to avoid other known

 

References

Wang, Y., Su, H., Gu, Y., Song, X., & Zhao, J. (2017). Carcinogenicity of chromium and chemoprevention: a brief update. OncoTargets and Therapy. Accessed: July 30, 2019.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5565385/