Erionite.

Plant availability of radiocaesium is usually high immediately after incorporation in a soil. However, for some Swedish soils, e.g, peat soils, a high radiocaesium uptake in plants has also been observed during a second growth period after contamination. For these soils the reduction in the plant availability of the nuclide seems to be a slow process. In the last two years the mineral zeolite has become of interest and has been tested as a caesium binding agent in both animal and in soil-plant systems. The aim of this study was to evaluate the time dependency and the effect of zeolite on the plant availability of radiocaesium in a peat soil-plant system. The pot experiments designed for this purpose were carried out in a climate chamber, using winter wheat as the test crop. A significant reduction of the uptake of 134Cs was obtained in wheat when increasing amounts of zeolite were added. This reduction in plant uptake, up to a factor of 8, might depend on two factors. One is that zeolite has reduced the activity concentration of radiocaesium in the soil solution available to the plant roots. The other is that the potassium added with the natural zeolite increased the degree of dilution of caesium in the soil solution. Also, increasing equilibration time for caesium in soil before sowing brought about an effective reduction in the caesium uptake.

Aluminum Silicates↗

PubMed1992

In vitro activity of silicon carbide whiskers in comparison to other industrial fibers using four cell culture systems.

Silicon carbide whiskers (SiCW) and continuous glass filaments are important components of composite materials having potentially widespread use in the automotive, aerospace, and power generation industries. We determined the in vitro activity of three well-characterized samples of silicon carbide whiskers and a continuous glass filament sample in four different cellular assays and compared this to the activities of UICC crocidolite, JM Code 100 glass microfiber, and erionite in the same assay systems. The SiCW had a diameter range of 0.32-0.75 microns and a length range of 4.5-20.1 microns. The SiCW was significantly toxic; on a mass basis, one SiCW sample was more toxic than crocidolite; however, JM Code 100 glass microfiber, which is not toxic in vivo (i.e., it does not cause fibrogenesis or carcinogenesis when inhaled), was also more toxic than crocidolite. The glass filament sample was the least cytotoxic of all the samples tested. On a fiber number basis, all three SiCW samples were more toxic than crocidolite. The results of our study showed that SiCW exhibits significant in vitro biological reactivity. Thus, despite the caution that must be exercised in extrpolating the results of in vitro studies to conclusions about in vivo health effects, SiCW should be considered toxic until further toxicological data are available.

Aluminum Silicates↗