Toxicity Concerns of Hexavalent Chromium from Tannery Waste

Environmental pollution by toxic heavy metals results largely from industrial activities, although sources such as agriculture and sewage disposal also contribute to some extent. Industrial wastewater discharged from tanneries contains hexavalent chromium and other toxic compounds. Chromium (VI) is soluble, toxic, mutagenic, teratogenic, and known to cause several adverse effects on human health. It can alter the genetic materials and cause cancer. The toxicity occurs in humans because of environmental pollution through soil or water contamination or due to occupational and non-occupational exposure of heavy metals. Chromium (VI) is transported into the cells through sulfate transport mechanism. To meet the challenge of toxic chromium (VI) pollution in environment, several treatment technologies such as physical, chemical and biological have been employed. However, the unregulated treatment process for disposal of polluted effluent has led to contamination of biotic and abiotic components of the environment. Whereas, bioremediation primarily using microorganisms offers a clean and cost effective technique for transforming toxic chromium (VI) into its non-toxic or less-toxic forms.