Chromium Sources, Toxicity and Recent Bioremediation Approaches: A Critical Review

ABSTRACT

Chromium (Cr) is a ubiquitous naturally occurring transition metal in the environment and an environmental pollutant of utmost significance. Chromium trivalent [Cr (III)] is an ultra‐trace element, whereas hexavalent [Cr (VI)] is highly toxic, mutagenic and carcinogenic with enormous risk to the environment and human health. This review article provides an overview of atmospheric, aqueous and terrestrial environmental chemistry of chromium and controlling parameters for speciation, mobility and bioavailability and also outlines the mechanisms of induction of oxidative damage, DNA damage. Apart from that, this review also expresses newly found bioremediation technologies of fungal, bacterial and algal microbial metabolic processes of Cr (VI) reduction to comparatively much less toxic Cr (III) via biosorption and bioaccumulation processes. New molecular biological, nanotech and omics technologies have been applied as evidence of improvement in efficiency of chromium remediation and optimization of extent and have potentialities for possibility cutting chromium pollution from contaminated ecosystems.