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Mass flux assessment can provide information that is essential for a sustainable management of elements in agricultural soils. In this article, we present an assessment of regional-scale averages of zinc (Zn) fluxes into agricultural soils and crops of central Iran for the period 1997–2011, using available databases such as regional agricultural statistics. The basic units of the balances were 15 townships of the provinces Qom, Isfahan and Fars. Averaged over the entire study region, the net Zn input into arable soil resulting from all fertilizer inputs – Zn removal with harvested crops was 1515 g ha−1yr−1across the entire region, with a range of 438–3009 g ha−1yr−1among townships. Estimated average Zn inputs with manure, mineral fertilizers, sewage sludge and compost were 1254, 531, 19 and 7 g ha−1yr−1, respectively. The input-to-output ratio of these fluxes ranged from 1.8 to 12.9 among townships and averaged 6.1 for the entire study area. Considering that outputs other than with crop harvests are minor, Zn stocks are rapidly building up in the soils of the study region. Uncertainties in the manure and crop removal data were the main sources of estimation uncertainty in this study. [ABSTRACT FROM AUTHOR]

Food, drinking water, soil, and air are the main routes of exposure to trace metals, thus the assessment of the risks posed to humans by these elements is important. Wheat, potatoes, and maize are very important parts of the Iranian diet. The objectives of this study were to estimate the non-carcinogenic and carcinogenic health risks of Hg, Pb, Cd, Cr, Se, As, and Ni to adults and children via soil, water, and major food crops consumed in Hamedan Province, northwest Iran, using the total non-cancer hazard quotient (THQ) and cancer risk assessment estimates. Total non-cancer hazard of Ni and Hg, were greater than 1, and total cancer risk of As and Pb was greater than 1 × 10−6. Food consumption was identified as the major route of human exposure to metals, and consuming foodstuff threatens the health of the studied population. In Hamedan Province, consumption of wheat is the main source of intake of metals from foodstuff for adults, and in children, the soil ingestion route is also important. [ABSTRACT FROM AUTHOR]

The article focuses on a study that examined the use of Soil and Water Assessment Tool (SWAT), with the Sequential Uncertainty Fitting program (SUFI-2), in testing and validating a hydrologic model of Iran based on various factors including river discharges, dam operations and irrigation practices. The study addressed the country's water balance including blue water flow, green water flow and the green water storage. The results depicted that irrigation practices have significantly affected the water balance of provinces whose people are engaging in irrigation farming. The implication of unstable water resource management on the country's food and water security is also explained.

Owing to the lack of regulations limiting pollutant concentrations in sludge and rates of sludge application on agricultural lands, high loads of heavy metals are introduced into agricultural soils by the use of sewage sludge as fertilizer in Iran. In order to examine the risk of metal transfer into vegetables arising from this practice under the farming conditions of central Iran, we performed a four-year field experiment in which we investigated the uptake of heavy metals from a sludge-amended soil (fine loamy, mixed thermic Typic Haplarigid) by lettuce (Lactuca sativa L.) and spinach (Spinacia oleracea L.). Sludge application rates were 0, 22.5, and 45 Mg ha -1 . To determine the effect of repetitive sludge applications, applications were repeated on two-thirds of each plot in the second year and on one-half of these subplots again in the third year. Thus, total sludge amounts applied were 22.5 and 45 Mg ha -1 in plots that received one application, 45 and 90 Mg ha -1 in plots with two applications, and 67.5 and 135 Mg ha -1 in plots with three applications. Single applications increased the EDTA-extractable concentrations of copper (Cu), zinc (Zn), and lead (Pb). Cadmium (Cd) concentrations increased only after two or three consecutive applications. In subsequent years with no further sludge applications, EDTA-extractable metal concentrations in soil showed a decreasing trend but, even after four years EDTA extractable metal concentrations were still significantly higher in plots that had received more than 45 Mg ha -1 sludge than in control plots. Metal uptake by the plants also increased with sludge application and decreased again after applications stopped. Close correlation with the EDTA-extractable soil metal concentrations suggests that EDTA is an effective indicator of plant-available metal concentrations in the investigated soil. Lettuce and spinach yields both increased significantly with all sludge application rates and this fertilizer effect was still evident three years after a single sludge application, indicating that sewage sludge can improve fertility of arid soils in the region. [ABSTRACT FROM AUTHOR]

Abstract: In most parts of Iran, water scarcity has been intensifying and posing a threat to the sustainability of agricultural production. Wheat is the dominant crop and the largest irrigation water user in Iran; hence, understanding of the crop yield–water relations in wheat across the country is essential for a sustainable production. Based on a previously calibrated hydrologic model, we modeled irrigated and rainfed wheat yield (Y) and consumptive water use (ET) with uncertainty analysis at a subbasin level in Iran. Simulated Y and ET were used to calculate crop water productivity (CWP). The model was then used to analyze the impact of several stated policies to improve the agricultural system in Iran. These included: increasing the quantity of cereal production through more efficient use of land and water resources, improving activities related to soil moisture conservation and retention, and optimizing fertilizer application. Our analysis of the ratio of water use to internal renewable water resources revealed that 23 out of 30 provinces were using more than 40% of their water resources for agriculture. Twelve provinces reached a ratio of 100% and even greater, indicating severe water scarcity and groundwater resource depletion. An analysis of Y-CWP relationship showed that one unit increase in rainfed wheat yield resulted in a lesser additional water requirement than irrigated wheat, leading to a larger improvement in CWP. The inference is that a better water management in rainfed wheat, where yield is currently small, will lead to a larger marginal return in the consumed water. An assessment of improvement in soil available water capacity (AWC) showed that 18 out of 30 provinces are more certain to save water while increasing AWC through proper soil management practices. As wheat self-sufficiency is a desired national objective, we estimated the water requirement of the year 2020 (keeping all factors except population constant) to fulfill the wheat demand. The results showed that 88% of the additional wheat production would need to be produced in the water scarce provinces. Therefore, a strategic planning in the national agricultural production and food trade to ensure sustainable water use is needed. This study lays the basis for a systematic analysis of the potentials for improving regional and national water use efficiency. The methodology used in this research, could be applied to other water scarce countries for policy impact analysis and the adoption of a sustainable agricultural strategy. [Copyright &y& Elsevier]

Abstract: There are no comprehensive food composition data on minerals and phytic acid (PA) contents of Iranian foods, which is an important prerequisite when assessing nutrient intake and nutritional status of the population. In this study, zinc (Zn) was analysed in major staples (rice, bread, and legumes; n =111), main animal source foods (dairy and meat products; n =107), and 9 local cooked dishes (n =38) consumed in a rural and a suburban population in central Iran. PA was additionally measured in the cereal and legume foods as well as the local dishes. Iron and calcium were also measured in selected raw and cooked samples of rice and legumes. The Zn concentration in cooked rice and bread were 0.88±0.34 and 1.32±0.16mg/100g of DW in the suburban area and 1.29±0.45 and 1.77±0.21mg/100g of DW in the rural area, respectively. The PA:Zn molar ratio of flat bread was 24 in the suburban and 22 in the rural area. Cooked rice and composite dishes had PA:Zn molar ratio between 4 and 13. The results indicated a low Zn absorption from the common flat breads but moderate absorption from the composite dishes. Food processing had a major influence on Zn concentrations in the final products. [Copyright &y& Elsevier]

Abstract: Geologic and pedologic controls have an important influence on the abundance, distribution and behavior of elements in natural soil environments. In order to assess the role of these factors on distribution and chemical speciation of selected trace elements in soil, soils on six parent materials including phyllite, tonalite, peridotite, dolerite, shale and limestone were sampled in western Alborz in Iran. Soil genesis and development of representative residual pedons were studied for each parent material and the total content of Si, Al, Fe, Ca, Mg, Co, Cr, Cu, Mn, Ni, Pb, V and Zn were compared. Enrichment/depletion patterns of trace elements were assessed using Ti as the reference element and lowest horizon as the reference layer. A modified BCR (European Community Bureau of Reference) sequential extraction procedure was used to fractionate the elements into four operationally defined species. The total contents of Co, Cr, Ni and V are highest in soils derived from peridotite (53, 984, 285, and 204 mg kg−1, respectively) and dolerite (39, 1023, 176, and 185 mg kg−1, respectively). Lead and Zn contents are highest in soils derived from shale (27 and 106 mg kg−1, respectively), which is probably due to the high sorption capacity of clay. Different elements exhibited very different enrichment/depletion patterns in a given pedon. Moreover, depth distribution patterns differed also for a given element among soils with different parent material and even showed considerable variation among soils with similar lithology. Lead, Zn, Cu and Mn have been generally enriched in most pedons, except in some acidic and strongly leached soils, whereas Co, Cr, Fe, Ni and V have been leached, especially from Dystrudepts and Eutrudepts. The latter elements, however, showed enrichment trend in Hapludalfs and Argiudolls parallel to the development of illuvial B horizons. Iron, Cr, Cu, Ni, V and Zn are present primarily in the residual fraction, independent of soil and parent material type, whereas Mn, Pb and Co were mainly present in the non-residual fractions of most pedons. Trace element concentrations in the soils of the study area are related primarily to the parent material type while pedogenic processes appear to have played a minor role. [Copyright &y& Elsevier]

Background: A large number of illnesses, afflicting one-third of the world's population, have been attributed to zinc deficiency. Inadequate dietary intake of bioavailable forms of zinc is considered the most frequent cause of zinc deficiency, which is most common in arid regions of developing countries., Objective: To employ a modeling approach in a test population to analyze how best to eliminate zinc deficiency using different plausible dietary scenarios., Methods: A comprehensive database was built upon food consumption patterns of two population groups residing in a village and a suburb in semiarid central Iran near Isfahan city. A database was created on zinc and phytic acid concentrations of different foods and ingredients consumed by the study populations. A zinc intake model was constructed and parameterized accounting for bioavailability and model input uncertainties., Results: The zinc intake of about one-third of both study populations, which did not differ significantly in their rates of zinc deficiency, was below the Estimated Average Requirement (EAR) for zinc. Scenario analyses predicted that at the current rate of food consumption, it would take up to 60 years for 97.5% of the population to meet their zinc EARs. Fortification of wheat flour and biofortification of wheat grains would result in 93% and 88% of the population, respectively, achieving their EARs in 15 years., Conclusions: The modeled results suggest that fortification and biofortification are the most effective and sustainable strategies to combat zinc deficiency. The methodology developed in this study is general and is shown to be a useful tool for the analysis of possible future trends and intervention scenarios., (© The Author(s) 2015.)

Elevated contents of mercury (Hg) and nickel (Ni) in soils and foodstuffs can threaten human health. As contents of these metals in soil, water and food vary from place to place, the associated risks will also be different in various parts of a region and it should be considered for environmental decision making and human health management. The objective of this study was to map the variation of human health risks related to Ni and Hg in soil, water and foodstuffs across an entire region, in province of Hamedan western Iran as an example case. Risks were calculated using the methods proposed by USEPA. The risk maps showed that total non-cancer relative risks of Ni and Hg were much higher than 1 (critical level). Risk of Ni in Razan and Kaboudarahang was higher than other counties. For some areas, relative non-cancer risks associated with exposure to Hg were estimated up to 7 and 11 in children and adults respectively. Consumption of plant foods particularly wheat was found to be the major route of human exposure to Ni and Hg. Soil ingestion was found to be another important route of human exposure to these metals., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The aim of this study was to estimate the zinc (Zn) and iron (Fe) status of different age groups in rural (Rooran) and suburban (Khomeini Shahr) populations in central Iran, to relate the Zn status to Zn intake from animal and plant foods, and to examine the relationship between Zn and Fe status. Blood samples from 341 subjects including preschool children (27), schoolchildren (157), women (91), and men (66) were analyzed for serum zinc (SZn), serum ferritin (SF), total C-reactive protein, and hemoglobin. Daily Zn and phytic acid (PA) intakes from major food groups were estimated using a 3-day weighed food record. The overall prevalence of Zn deficiency based on low SZn was 5.9 % in Rooran and 7.2 % in Khomeini Shahr. Anemia was higher in the village than in the suburb (33.5 % vs. 22.7 %; p = 0.04) and almost half of the anemia in Khomeini Shahr and 36 % in Rooran was associated with iron deficiency (ID) based on low SF. The PA:Zn molar ratio in the diet was 10 - 13, indicating a diet of moderate Zn bioavailability. About 18 % of the population consumed less Zn than their WHO Estimated Average Requirements. There was no association between Zn status and Fe status. The modest prevalence of Zn deficiency in the study populations can be explained by a relatively high Zn intake from animal source foods. Anemia however is a serious public health problem affecting some 30 % of the subjects, with almost half due to ID. The lower Fe status than Zn status could be due to the frequent consumption of tea and dairy products.