Chromium Toxicology

Chromium toxicology centers on a metal whose toxicity is critically dependent on its oxidation state, with hexavalent chromium (CrVI) being of primary occupational health concern. This topic is vital for Zambian university students in occupational health, industrial hygiene, and toxicology, particularly in contexts involving welding, plating, and tannery work. The topic contrasts the relatively low toxicity and poor absorption of trivalent chromium (CrIII) with the high toxicity of CrVI, which is readily absorbed and intracellularly reduced to CrIII, generating reactive intermediates that cause DNA damage. The principal focus is on CrVI as a known human carcinogen, specifically inducing lung cancer among exposed workers via inhalation of dusts or mists. Students will learn about the mechanism of bronchogenic carcinoma development and other non-cancerous respiratory effects like irritation and ulceration. Understanding chromium toxicology is essential for performing well in tertiary examinations and for developing and enforcing workplace exposure limits and safety protocols to protect workers in Zambia's growing industrial sector.