Effects of Heavy Metals Especially Selenium,Vanadium and Zirconium on Movement,Growth and Survival of Certain Animal Aquatic Life.

摘要

The heavy metals Selenium (as H2SeO3and as Na2SeO3),Vanadium (as VOSO4.2H2O) and Zirconium (as ZrOCl2.xH2O) were tested for potential toxicity to the growth and swimming rates of the ciliated protozoan, Tetrahymena pyriformis. Vanadium and Zirconium,as used,were found to be less toxic in small amounts than some other metals previously tested, e.g.,Cadmium. Neither inhibited growth significantly at amounts below five parts per million (5ppm). Selenium as selenous acid (H2SeO3) slightly stimulated growth at 5to 15ppm;but as selenite (Na2SeO3) it completely blocked growth at all concentrations tested, 3to 20ppm. Vanadium did not affect growth at 3to 15ppm,but depressed it in greater amounts. Zirconium at concentrations of 3to 15ppm slightly stimulated growth,but depressed it at higher amounts. All three metals,however,inhibited swimming at concentrations over 5ppm,selenium being the more toxic,stopping swimming in 30ppm in less than 1hour. Concentrations of any of the three metals above 20ppm are detrimental to the growth and survival of Tetrahymena pyriformis.