20. Solving a chemistry problem

74. If an excess of nitrogen fertilizers is applied to the soil, then harmful salts - nitrates - accumulate in fruits, leaves, root crops. Once in the human digestive system, they are reduced to nitrites, and this threatens with poisoning: nitrites oxidize blood hemoglobin, depriving it of its ability to carry oxygen. Most nitrates accumulate dill, lettuce and parsley, to a lesser extent - beets, cabbage and carrots. Potatoes, tomatoes, apples almost do not accumulate nitrates: their content in these products rarely exceeds 100 mg/kg. Is it possible to eat cabbage containing 2.4 * 10-3 mol of potassium nitrate in 1 kg?