Bio-accumulation of environmental residues of rare earth elements in aquatic flora Eichhornia crassipes (Mart.) Solms in Guangdong Province of China

Scattering and bio-accumulation of rare earth elements (REEs), including the inner transition series, in the aquatic environment in southern China have resulted from increased industrial and agricultural applications. Environmental residues of REEs entered into aquatic flora, namely Eichhornia crassipes, commonly known as water hyacinth, via the root system in contaminated substrate water and could distribute to various parts of the plant. REEs could also bio-accumulate and concentrate in the leaves at a concentration ratio of approx. 3 times regardless of initial REE concentration in the substrate water. REEs could also enter into the plant via the leaves that are exposed to atmospheric contaminants. While officially permitted residual concentrations of mixed REE nitrates in foodstuffs or animal feedstocks are not available, high REE concentrations in the substrate water in which water hyacinth grew could possibly enter the human food chain and lead to adverse public health problems.