Strontium (Sr) is accumulated in plant calcium oxalate crystals to a concentration far in excess of the concentration the plant is exposed to. 90Sr is a major constituent of nuclear fallout and nuclear industry processes, which can readily be incorporated into bone tissue. Given the high toxicity of 90Sr, its long half-life and the real possibility of it being released into the environment, research aimed at determining if Sr from ingested plant crystals can be incorporated into mammalian tissues is proposed. Various tissues of mice exposed to a diet of plants having Sr oxalate crystals will be analyzed by energy dispersive X-ray analysis (EDXA) to determine if Sr from the crystals can be incorporated into the tisuses as soluble or insoluble deposits. The possibility of transfer of Sr from mother to fetus will also be explored. Such studies will help to establish an understanding of the health risks imposed by this accumulation process. Numerous toxic metals are released to the environment as a result of various industrial practices, waste disposal inadequacies and accidents. Recent evidence indicates that one of these metals, cadmium, is incorporated into plant calcium oxalate crystals. Considering the ubiquity of crystals in crop species, studies to establish the range of toxic metals incorporated into plant crystals and the prevalence among plant species of this phenomenon are proposed. Crop plants and aquatic plants, which may be useful as bioindicators of contamination, will be exposed to various toxic metals and analyzed by EDXA for both soluble and insoluble (crystals, cell wall) deposits of metals. Another objective of the proposed research is to investigate the mechanisms that regulate the accumulation and incorporation of Sr into plant crystals. An understanding of such mechanisms may lead to strategies to inhibit the accumulation process or to utilize the process for cleanup of contaminated areas. The overall objectives of the proposed research are to identify the range of toxic metal ions that can be incorporated into plant crystals and to characterize the potential health risks this accumulation phenomenon may pose, especially with respect to Sr, which is a deadly longlived product of nuclear processes.
| Li, X X; Franceschi, V R (1990) Distribution of peroxisomes and glycolate metabolism in relation to calcium oxalate formation in Lemna minor L. Eur J Cell Biol 51:9-16 |
