Piyanut Peebuaปิยะนุช ปี่บัวMaleeya Kruatrachueมาลียา เครือตราชูPrayad Pokethitiyookประหยัด โภคฐิติยุกต์Pahol Kosiyachindaพหล โกสิยะจินดาMahidol University. International College. Science Division.2014-10-242018-02-222014-10-242018-02-222014-10-242006Science Asia Vol. 32, (2006), 143-50https://repository.li.mahidol.ac.th/handle/20.500.14594/8787Histopathological biomarkers of toxicity in fish organs are a usful indicator of environmental pollution. Nile tilapia, Oreochromis niloticus exposed for one month to sediments from the Mae Klong River, Samutsongkram province, South West Thailand, which contained elevated levels of heavy metals (lead and chromium), developed abnormalities of the gills, liver and kidney. In the gill filaments, cell proliferation, lamellar cell hyperplasia, and lamellar fusion were observed. In the liver, there was vacuolation of hepatocytes and nuclear pyknosis. Kidney lesions consisted of dilation of Bowman’s space and accumulation of hyaline droplets in the tubular epithelial cell. No recognizable changes were observed in muscle tissue. Despite these histopathological changes, no firm correlation between levels of heavy metals in sediments and those in fish tissues could be established.engMahidol UniversityHistological effectsContaminated sedimentsMae Klong riverOreochromis niloticusArticleThe Science Society of Thailand and the National Research Council of Thailand.