Cadmium Contamination, Bioavailability, Uptake Mechanism and Remediation Strategies in Soil-Plant-Environment System: a Critical Review

Abstract

Background: Cadmium contamination is becoming severe and intense issue for the ecosystem due to its highlevel toxicity and carcinogenic nature. It comes from different sources and affects environment and human health. This review paper is aimed to address different sources of cadmium, its toxic effects on environment and human health as well as to discuss influence of different soil factors in changing speciation and bioavailability of cadmium in soil. This paper also covers research on different remediation strategies for alleviating cadmium bioavailability. Methods: Previous Research and critical comparison of cadmium extent, toxicity, effects and management was studied. Results: Cadmium carcinogenic nature is of concern for human health. Cadmium is found as in free state and in complex form, but its availability depends on its speciation in soil. Oxidizing conditions and high pH decrease cadmium bioavailability and speciation in the soil. organic matter act as a sink as well as a source of cadmium. Microbes carried out many mobilization processes include protonation, chelation, and chemical transformation whereas, sorption or precipitation and hinders cadmium availability. Continuing exposure to cadmium can result in browning, decomposing and mucilaginous roots; shoot reduction and apical growth of root, chlorosis and rolling of leaves. Its toxicity may inhibit lateral root formation or can result in rigid, twisted and browning the main root. Its toxicity also affects photosynthesis and availability of mineral nutrients. In this paper, the remediation techniques of soil polluted by Cd, including biological, chemical and physical remediation are reviewed. The methods of remediation, developing trends, drawbacks and strengths were reviewed to provide a reference to the research in this field. Conclusion: Although cadmium toxicity is of great concern, but many remediation techniques can be used to hinders its adverse effects. Phytoremediation, hyper accumulation, bioremediation and use of different amendments proved significant results in alleviating cadmium bioavailability. Among all techniques, in-situ immobilization with inorganic, organic or clay amendments is an environmentally friendly and cost-effective strategy to remediate cadmium contaminated soils and sustainable agriculture production.

Differentiating Wild and Apiary Honey by Elemental Profiling: a Case Study from Mangroves of Indian Sundarban

“…Cadmium (Cd) naturally presents in the environment with less than 1 μg/g but mishandling and overuse result in biomagnifications of Cd in successive trophic levels [93][94][95]. The maximum, minimum, and average concentration in wild honey samples were 6.25 μg/kg (Kumirmari-HW8), BDL and 1.34 ± 2.10 μg/kg whereas in apiary honey samples the above said concentrations were 5.23 μg/kg (Lothian Wildlife Sanctuary-HA9), BDL and 2.03 ± 1.91 μg/kg.…”

Salicylic acid improves Nasturtium officinale phytoremediation capability for cadmium-contaminated paddy soils

“…The major pollutants in the soil are heavy metals. The major heavy metals causing soil contamination is cadmium (Cd), which far exceeds the contamination due to other heavy metal elements ( Riaz et al., 2021 ). As a non-essential element, excessive Cd causes toxicity and affects the growth of plants ( Garg et al., 2015 ; Vatehová et al., 2015 ).…”

Bioremediation of Soil Pollution Based on Fungal Immobilization Technology

“…And man-made economic activities make the content of lead in the soil exceed the standard value, resulting in a decline in the quality of the soil ecological environment. The burning of leaded gasoline, coal (thermal power plants), and ore smelting in other high-temperature industries are the main sources of anthropogenic lead in the environment, and agricultural soils are exacerbated by livestock manure, atmospheric deposition, fertilizer application, sewage irrigation, and solid waste deposition lead content in [1][2].…”