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), includi ng the inner transition series, in the aquatic environment in southern China have resulted from increased industrial and agricultural applic ations. Environmental residues of REEs entered into aquatic flora, nam ely Eichhornia crassipes, commonly known as water hyacinth, via the ro ot system in contaminated substrate water and could distribute to vari ous 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 e nter into the plant via the leaves that are exposed to atmospheric con taminants. While officially permitted residual concentrations of mixed REE nitrates in foodstuffs or animal feedstocks are not available, hi gh REE concentrations in the substrate water in which water hyacinth g rew could possibly enter the human food chain and lead to adverse publ ic health problems. (C) 1998 Elsevier Science B.V.