Comparing the Nitrate Level in Vegetables Irrigated with Zayandehrood River and Well Water

High intake of nitrate and nitrite is harmful for human health. Vegetables are the major source of nitrate and nitrite in human diet. The objective of this study was to compare the amount of nitrate and nitrite in vegetables irrigated with Zayandehrood’s water and well water. 106 samples of eight top used vegetables (cucumber، tomato، onion، leek، lettuce، potato، parsley، and spinach) irrigated with Zayandehrood’s water and 106 samples of those vegetables irrigating with well water from east of Isfahan were randomly selected، and nitrate and nitrite levels were determined by spectrophotometric method. The mean value of nitrate in cucumber، tomato، onion، leek، lettuce، parsley، spinach، and potato irrigated with Zayandehrood’s water was 30 ± 1. 1، 30. 7 ± 1. 4، 45. 2 ± 2. 6، 230. 7 ± 4. 3، 173. 8 ± 19. 3، 319. 7 ± 8. 4، 321. 2 ± 18. 5 and 62. 2 ± 2. 0، respectively. The mean nitrate level in cucumber، tomato، onion، leek، lettuce، parsley، spinach and potato irrigated with well water was 26. 7 ± 0. 9، 26. 7 ± 2. 8، 28. 4 ± 2. 9، 161. 8 ± 20. 6، 275. 7 ± 58. 2، 312. 5 ± 37. 4، 311 ± 28. 7 and 116. 9 ± 0. 06، respectively. Independent t-test showed that mean nitrate level in cucumber، tomato، onion and leek irrigated with Zayanderood’s water was significantly higher than those vegetable irrigated with well water (P = 0. 001). The mean nitrate level in parsley and spinach had no statistically significant difference. In different vegetables، the mean nitrate level was not equal. In these samples، cucumber and tomato had the lowest amount of nitrate. Parsley and spinach had the highest amount of nitrate. The mean nitrate in the most of vegetables irrigated with Zayandehrood’s water was significantly higher than those vegetable irrigated with well water; thus it is necessary that industrial wastes is disposed correctly because they treat our life.