Histopathology of Internal Organs of Fish Living in Lignite Mine

The acidity of mine water generally makes it toxic to most organisms. The gills, kidneys and livers of Anabas testudineus Bloch fish inhabiting the acidic water (pH 2-4) of an unused lignite mine in Li District, Lamphun Province, Thailand were examined and compared to those of farmed fish. Tissue abnormalities were found in all investigated organs. Deterioration and telangiectasia of gill filaments were found. Liver tissue revealed hemorrhages, blood congestion and necrotic cells with mononuclear cell infiltration. In addition, hypertrophy of the epithelial cells of the renal tubules with reduced lumens, aneurisms of the renal tubules, and contractions of the glomeruli in the Bowman’s capsule were observed. These histopathological findings suggest the acidic water in this habitat causes severe damage to the internal organs of fish and consequently alter their physiological status. Since the water in this pond is utilized by local people, these findings highlight the need for adequate water treatment. been used as biomarkers (Hinton et al, 1985). Fish diseases and pathologies have also been used as indicators of environmental stress (Matthiessen et al, 1993). Acid water resulting from mining activity is highly toxic to most aquatic life. In this case, the acidity is not only harmful to aquatic life but to the food chain (Cotter and Brigden, 2006). The ecological effects of aquatic pollutants are related to species distribution (Mosisch and Arthington, 2000). This study investigated the histological alterations caused by environmental contaminants in the gills, liver and kidneys of A. testudineus inhabiting unused acid mines at Ban Pu, Li District, Lamphun Province, Thailand. MATERIAL AND METHODS Adult Anabas testudineus fish (n = 10) were procured from an unused lignite mine INTRODUCTION The water reservoir at Ban Pu, Li District, Lamphun Province, Thailand is an abandoned lignite mine, whose water is highly acidic. However, surprisingly a population of climbing perch fish (Anabas testudineus) inhabit this water. Because of direct and continuous contact with the environment, fish gills, organs for respiratory gas exchange, osmoregulation, excretion of nitrogenous waste products and acid-base regulation, are directly affected by contaminants. Histopathological features of the liver, ovaries, skeletal system and skin of organisms exposed to one or more toxins have SOUTHEAST ASIAN J TROP MED PUBLIC HEALTH 1122 Vol 40 No. 5 September 2009 (pH 2-4) at Ban Pu, Li District, Lamphun Province, Thailand. The liver, gills and kidneys were sectioned 1-2 mm, in thickness and fixed in 10% formalin and processed according to standard paraffin procedures. Five micrometer thick paraffin sections were placed on glass slides and stained with hematoxylin and eosin. Approximately 2-4 paraffin sections of each fish were histologically analyzed under a light microscope. Histopathological changes in these tissues were recorded and compared with controls under the guidance of a pathologist.