Buba et al. J Biomed & App Sci FUD (2025) 4:2
Keywords: Mercury, Histology, Histochemistry, Lungs, Trachea.
2026-03-26 DOI: JOBASFUD_2025_4_2_001
Background: Mercury is a member of the family of metallic element known as the heavy metals. Toxicity of mercury has continued to occur in Iraq, Taiwan and in Nigeria killing several thousand people thereby placing mercury among top-most toxic metals. Despite documented cases of mercury chloride poisoning showing respiratory symptoms such as dyspnea, chess pain and chemical pneuminitis, the precise anatomical mechanisms by which mercury chloride disrupt the primary respiratory areas remain inadequately understood. Most published research overlooks detailed respiratory tissue analysis focusing instead on other organs. The microscopic and chemical alterations in the respiratory tract due to mercury chloride exposure also remains underexplored, despite known exposure and systemic risk. Methods: This study assesses mercury chloride administration on the histology and histochemistry of the lungs and trachea. Thirty adult Wistar rats were used for the purpose of this study. The rats were grouped into three (3) groups of ten (10) rats each. They were administered 2mls of distilled water, 5mg/kg and 10mg/kg body weights of mercury chloride respectively for fourteen (14) days. The rats were weighed daily using manual weighing balance and electronic weighing balance was used to weigh the organs after sacrifice. Results: The results showed that mercury caused hemorrhage, collapse and coalition of the alveolar wall, necrosis of the pneumocytes as well as depletion of the epithelial lining of the trachea. Mercury also caused an increase in the production of mucins in lungs. The presence of these mucus-secreting cells suggests an adaptive response to irritation or inflammation, which is commonly observed in various respiratory conditions. Conclusion: mercury alters the histology and histochemistry of the lungs and trachea.