Uranium Sources, Uptake, Translocation in the soil-plant System and Its Toxicity in Plants and Humans: A Critical Review

Uranium(U) is one of the highly toxic heavy metals and radionuclides that has become a major threat to soil health. There are two types of sources of Uranium in the soil system, natural and anthropogenic. Natural sources of uranium include rock systems and volcanic eruptions while anthropogenic sources include mining activities, disposal of radioactive waste, application of phosphate fertilizers, etc. Uranium accumulation impacts germination, early seedling growth, photosynthesis, metabolic and physiological processes of the plants. Through its accumulation in the aerial parts of the plants, Uranium finds its way to the human body, where it has deleterious health impacts. Different studies have identified the various sources of Uranium, explored, and explained the geochemistry of Uranium in soil, assessed the Uranium uptake and toxicity to the plants, and further studied the impact on human health. Most studies focused on two stages, either soil-plant or plant-human system. However, few studies have critically reviewed and summarized the U in the soil-plant-human system. Thus, the review has been designed to focus on the sources, geochemical behaviour, uptake, and translocation, plant toxicity, food chain entry, and finally, impact on human health. The relationship between the bioavailability of Uranium in the soil-plant system with soil properties like pH, Organic matter, and microorganisms have also been included. The study is further intensified by analyzing the accumulation of Uranium in various parts of the plants.