Deliberations on the microplastic-guided rare heavy metal toxicity in agricultural crops grown around nuclear reactors: molecular regulation and strategies for remediation

Rapid growth in the nuclear energy sector has led to increased construction of nuclear power plants (NPPs). Although this promotes the generation of alternate sources of "clean" energy that does not harm the environment, potential concerns regarding soil and water pollution with microplastics and multiple rare heavy metals (HMs) used in NPPs usually do not grab the required attention. The group of rare HMs comprises of uranium, cadmium, mercury, cobalt, germanium, and indium, which are known ecological toxins affecting agricultural quality and consumer safety. When expunged as nuclear waste discharges, these rare HMs adsorb to the surface of microplastics and together pollute the adjacent cultivable lands and water sources used for irrigation. Microplastics increase the phyto-availability of the HMs, which mimic micronutrient elements and are actively transported into root cells via calcium, iron, zinc, copper, or other HM transporters. The toxicants are then translocated to aerial biomass and reproductive or storage organs via the symplastic or apoplastic routes. Humans or animals consuming such contaminated crops and vegetables can develop irreversible neurological and physiological disorders, including cancers. Plant growth regulators like abscisic acid, gibberellic acid, and nitric oxide have been found to synchronize the stress-adaptive signaling in crops, although the sensitive genotypes ultimately succumb to oxidative injuries. To abate such ecological and economic loss, remote sensing can be used to avoid contaminated areas or bio(phyto)remediation can be performed to depollute contaminated landscapes and water bodies. Genetically engineered, tolerant crops can also be cultivated directly, with lower yield loss.