Vegetables as one of the most important sources of nitrate, have positive and negative effects on human health.The goal of this paper was to estimate the nitrate concentration in vegetables production in Pol-e Dokhtar County as one of the main centers of Iranian vegetable production and the possible health risks correlated with high concentration of nitrate in theses crops. Using United States Environmental Protection Agency (USEPA) method, the risk was evaluated and presented as risk diagrams. Additionally, type, amount and method of fertilization in farms with different concentrations of nitrate in vegetables were presented. Almost, all results were within the range of nitrate concentrations in vegetables. Lettuce and Persian leek (716.200 and 378.500 mg NO3 − kg−1 FW, respectively) were the most and least predominant contributors in total NO3 – uptake, respectively. The risk diagrams showed that all values were lower than the acceptable levels for each of vegetables. Furthermore, in most age groups, this index was greater in women than in men. According to the information in the questionnaires, perhaps one of the most important factors in reducing the nitrate accumulation in the vegetables of Pol-e Dokhtar is due to optimal and timely use of fertilizer. Use of nitrogen fertilizers in form of split in 73% of fields decreased the nitrate concentration in plants with no reduction in yield. Therefore, considering crop yields and nitrate accumulation impacts, improved nitrogen management could provide an opportunity to promote production of vegetables and reducing the effects of negative health in high-risk regions in Lorestan Province. پرونده مقاله

Pollution caused by heavy metals, due to their toxicity and harmful effects on plant species, is considered one of the fundamental problems. The unique properties of graphene oxide (GO) in adsorbing heavy metals from contaminated soil systems have garnered attention in the past decade. This study evaluates the effects of different doses of graphene oxide (0.5 and 1.5 g kg-1) on the adsorption and distribution of heavy metals, including Cadmium (Cd) and Copper (Cu) fractions, in soil contaminated with two rates (2% and 10%) of sewage sludge (SS) over a 92-day period. Subsamples were collected from the soils at intervals of 5, 15, 29, 57, and 92 days, air-dried, and subjected to metal fractionation. The aim was to evaluate the separation of Cd and Cu by employing a five-stage sequential extraction technique, where each stage involved 2 grams of air-dried soil as a sample. The overall metal quantity in the treatments was determined by utilizing aqua regia digestion. The recovery rate was determined by calculating the percentage of the total metal concentration obtained from acid digestion, involving the summation of the concentrations of the five metal fractions. The results showed that the F1 fraction of heavy metals in the soil with a 2% SS rate decreased with an increase in GO dosage. The calculated mobility factor of the metals at five incubation times (5, 15, 29, 57, and 92 days) was found to be in the range of 28.1-60.9 for Cd and 14.4-25.3 for Cu, indicating a higher mobility of Cd. The findings suggest that the presence of GO as an adsorbent and the incubation time were critical parameters in stabilizing heavy metals in the soil with different rates of SS. Additionally, the nature of the applied SS was found to influence the fractionation of heavy metals in the soil, besides providing elements. پرونده مقاله