[Effect of drinking water with a high nitrate content on the body in a toxicological experiment]

A chronic, four-month, toxicological experiment with albino rats was carried out with a view to study the effect of nitrates on organism. The animals, grouped into six groups, were daily intoxicated by probing with aqueous solution of sodium nitrate in concentrations of 30, 50, 100, 500 and 1000 mg/l. The toxicological studies established statistically significant changes in some integral, hematological, biochemical and pathologico-anatomical indices with the drinking of potable water with 500 and 1000 mg/l nitrates and in single cases - with 100 mg/l: body weight loss among the female animals; reduction of hemoglobin and erythrocytes; urea fluctuation (hypo- and hyperazotemia); increase of glutathione, of peroxidase activity and alkaline phosphatase; reduction of catalase activity; light parenchymal-dystrophic changes in liver and kidneys. No changes were established in methemoglobin. With a view to those results, the authors presume that no risk for organisms exists with the consumption of potable water, containing nitrates to 50 mg/l, a slight risk--up to 100 mg/l, enhanced risk--over 100 mg/l and high risk--with 500 and over 500 mg/l.