ACUTE TOXICITY OF HEAVY-METALS (COPPER, LEAD, ZINC), PHENOL AND SODIUM ON ALLIUM-CEPA L, LEPIDIUM-SATIVUM L AND DAPHNIA-MAGNA ST - COMPARATIVE INVESTIGATIONS AND THE PRACTICAL APPLICATIONS

The investigations of the effects of various heavy metal: Cu (as CuSO4 ), Pb (as Pb(NO3)(2)) and Zn (as ZnSO4), phenol and Na (as Na2SO4 and NaCl) concentrations on root length of onion bulbs (Allium cepa L.) an d garden cress (Lepidium sativum L.), as well as on the survival rate of great water flea (Daphnia magna St.) showed varied sensitivity of t he above test organisms. Based on IC50 Value (50% inhibitory concentra tion) for A. cepa L. and L. salivum L. and on LC5O value for D. magna St., the acute toxicity of the tested substances decreased after a 48- hour exposition in the following order: A. cepa L.: Cu > Pb > Zn > phe nol > Na2SO4 > NaCl; L. sativum L.: phenol > Cu > Pb > Zn > Na2SO4 > N aCl; D. magna St.: Cu > Zn > phenol > Pb > Na2SO4 > NaCl.