[Values of nitrate and nitrite in selected vegetables and potatoes cultivated in the region of Puław].

Nitrate and nitrite contents were determined in selected vegetables and potatoes from plantations of individuals farmers, situated either in the vicinity of the Nitrogen Plant in Puławy or at a distance from this plant (control). Vegetables and potatoes both newly harvested and stored for 4 months in cellars were analysed. From farms selected by lot, samples of lettuce, cabbage, sauerkraut, beets, carrots and potatoes (all harvested in 1986 and 1987) were collected. Nitrate and nitrite contents were determined in 1215 plant samples. Nitrates were reduced on a cadmium column to nitrites, whereupon they were determined colorimetrically using sulphanilic acid and N-1-naphthylethylenediamine. This results showed that the nitrate contents are higher in the vegetables and potatoes cultivated in the region of the Nitrogen Plant, as compared with those from the Janowiec village distant from this plant (control). Differences in mean nitrate contents per 100 g dry matter were in years 1986 and 1987 for: lettuce 73%, 36%; cabbage 54%, 39%; beets 16%, 20%; carrots 51%, 29%; potatoes 77%, 36%, respectively. Moreover, the vegetables and potatoes grown in the region of the Nitrogen Plant, as compared with the control vegetables from the village located at a distance from this plant, displayed a greater percentage of samples with plants characterized by higher nitrate contents. The greater percentage of samples containing high nitrate levels, as well as the higher mean nitrate contents in vegetables and potatoes testify to the effect of the Nitrogen Plant on nitrate concentrations in the crops. In vegetables from both regions, the nitrite contents did not exceed 1 mg NaNO2/kg.(ABSTRACT TRUNCATED AT 250 WORDS)