Hexavalent chromium induces testicular dysfunction in small Indian mongoose (Herpestes javanicus) inhabiting tanneries area of Kasur District, Pakistan

Hexavalent chromium (Cr-VI) is widely used in tanning industries, however, being highly toxic metal, its accumulation in the animal body can adversely affect reproductive functioning. If directly discharged untreated into the environment (adjoining nullahs and soil), it can contaminate the environment. Resultantly, along with human, inhabiting wildlife species get exposed to chromium toxicity, which may enter into the animal body through drinking water and food chain. The current study investigated toxic effects of Cr (VI) on testicular functioning of adult male small Indian mongooses inhabiting the tannery area of Kasur district, Pakistan. Soil, water and animal specimens were sampled from study area on monthly basis from February 2015 to January 2016. The captured mongooses were sacrificed to collect blood and body tissues (liver, kidneys and testes) samples. The concentrations of chromium in the samples were quantified using atomic absorption spectrophotometry. Hormonal concentrations were estimated using ELISA kits. The cellular changes occurring in the testicular tissues were studied through light microscopy. Average Cr-concentrations were found significantly higher in experimental area soil and water samples, and in the blood and body tissues of the mongooses compared to control, while body and testicular weights of experimental animals were found reduced. Serum testosterone (p = 0.037) and luteinizing hormone (p = 0.000) levels were found significantly lowered while follicle stimulating hormone (p = 0.000) levels significantly increased in experimental animals. Histological analysis revealed disorganization of seminiferous tubules, and apparently decreased numbers of Sertoli and the Leydig cells. Spermatozoa and seminiferous tubular counts were also found significantly (p = 0.000) reduced compared to control. Interstitial spaces were found widened. The study concludes that Cr from tanneries environment is up taken by mongooses leading to testicular tissue damage and potential impairment of reproductive functioning of the species.