Environmental Cadmium Toxicity and Its Bioremediation

Heavy metal pollution is nowadays a serious issue of global concern. Heavy metal pollutants, including Pb, Hg, Cr, Se, and Cd+2 (cadmium), enter the environment from various sources and potentially contaminate every part of our environment, such as soil, water, and the air. Cd+2 is a malleable, bluish-white metal—atomic number 48, a d-block element—that is associated with zinc ore impurities. Rapid urbanization, industrialization, and anthropogenic and natural activities contribute to Cd+2 pollution. Cd+2 leaches into water supplies and contaminates lakes, ponds, streams, river, and groundwater. Cd+2 is corrosion resistant and used primarily in batteries, plastics, pigments, and metal coatings. Cd+2 is a potent toxin and adversely affects vegetation, aquatic life, and land animals, including humans. It is a potent carcinogen and mutagen and may induce cancer, DNA malfunctioning, and chromosomal aberrations. The other toxic effects of Cd+2 include growth retardation and liver, kidney, and other organ toxicity. Cd+2 is not easily metabolized, persists for a long time in the environment, and is difficult to remove. The available chemical and conventional approaches to bioremediation are not efficient. Bioremediation, which includes both the remediation of both plants (phytoremediation) and microbes (microbial remediation), is a sustainable and economical approach to managing Cd+2 pollution.