“…The heavy metal contamination may affect human via the food chain (Arif et al, 2019 ) as Cd, Hg, As, and Pb are among the top 20 toxic heavy metals according to the Agency for Toxic Substances and Disease Registry (ATSDR) and the US Environmental Protection Agency (EPA). Heavy metals endanger food production (Irshad et al, 2020 ; Javaid, 2020 ), while NPs may boost seed germination, photosynthetic rate, antioxidant defense system, yield, and plant vigor (Lian et al, 2020 ; Usman et al, 2020 ; Wang et al, 2020 ). Experts agreed using NPs to combat the varied effects of toxic ions on plants (Liu et al, 2018 ; Rizwan et al, 2018 ), as CuO NPs (50 and 100 nm) alleviated adverse effects of As on the number of root branches in rice ( Oryza sativa L. subsp.…”