Toxic heavy metals: A bibliographic review of risk assessment, toxicity, and phytoremediation technology

Heavy metal contamination of soil is becoming a life-threatening issue causing serious threat to our ecosystem. These metals reduce the potency of soil and affect the entire environment negatively. In plants, these metals inhibit the rate of photosynthesis, production of major proteins and enzymes. Decrease in the trend of seed germination, premature- growth have also been observed. Phytoremediation is a modern strategy that is used for treatment of contaminated soil using various methods, including phytoextraction, phytostabilization, phytovolatilization and phytofiltration. Phytoremediation has gained importance over different physical and chemical methods like soil replacement, washing policies and solidification as it is cost-effective and easy to adopt technology. The utilization of this green technology has benefited mankind via the reduction of heavy metal accumulation in plant parts, specifically non-edible plants. In view of the several merits of the green technology, this review paper discussed several literatures published on heavy metal toxicity, their risk assessment and phytoremediation method, while various research gaps were suggested to tackle some challenges inherent in phytoremediation approach for the treatment of heavy-metal contaminated soils.