ABSTRACT

The reason of the interest shown in the properties of NTA is the possibility of its use for the replacement of polyphosphates in washing powders which are the cause of water eutrophization. In the light of literature data the chemical properties of NTA and the conditions influencing the course of the reaction of complex formation with metal ions in aqueous solutions are discussed Equilibrium constants of these reactions are presented, with diagrams obtained in computer assisted analysis of the conditions of equilibrium of NTA reaction with metal ions in the solutions occurring in physiological conditions and in the environment. On the basis o f the opinions of expert committees the toxicity of NTA for mammalian organisms are described. It has been shown that NTA has no teratogenic or mutagenic action, however, in 2-year observations of mice and rats the intake of NTA produced lesions of uroepithelium with development of turn ours. This effect of NTA has been demonstrated to be closely connected with its property of complex formation with metal ions. Experiments are described in which confirmation was obtained of the hypothesis that pathological lesions of renal tabules are caused by accumulation of zinc and bladder tumours are caused by binding by NTA of calc ium from epithelial cells.