Major and trace elements levels in multifloral and unifloral honeys in Croatia

Different honey types were collected in Croatia during 2010 and 2011: 7 multifloral orchard honeys, 7 multifloral meadow honeys, 19 black locust, 9 chestnut, 11 lime and 6 sage honeys. Elements were measured using graphite (As, Cu, Cd, Pb, Se) and flame atomic absorption spectrometer (Ca, Fe, K, Mg, Na, Zn) and by mercury analyser (Hg). Significant differences in Ca, Fe, K, Mg, Zn, As and Hg levels were observed between honey types. In chestnut honey were determined (K, Ca, Mg: mg kg⁻¹; Hg, Ad, Cd: μg kg⁻¹): the highest concentrations of K 2824.4, Ca 486.7, Mg 59.1 and Hg 2.52; the lowest of As 24.1 and Cd 2.52. Lime honey has been shown the highest content of Cu (20.6 mg kg⁻¹), Zn (6.78 mg kg⁻¹), Cd (2.14 μg kg⁻¹) and Pb (810.3 μg kg⁻¹). The lowest levels of following elements were determined in black locust honey (Fe, K, Mg: mg kg⁻¹; Hg: μg kg⁻¹): Fe 2.77, K 304.7, Mg 8.02 and Hg 0.82. Sage honey had the lowest Ca and Na content (173.9 and 31.8 mg kg⁻¹). Among the multifloral honeys, the following was determined (Fe, Na, Cu: mg kg⁻¹; As, Pb: μg kg⁻¹): orchard honey – highest of Fe 5.17 and As 276.1, lowest Pb 301; meadow honey – highest Na 36.1, lowest Cu 4.38. The average Ca, Cu and Pb levels found in multifloral honey types were much higher than those reported in other European countries. Calcium levels in lime, chestnut and black locust were higher than those from other countries.     

A Brazilian Total Diet Study: Evaluation of essential elements

Total Diet Study (TDS) has been adopted worldwide and is based on the evaluation of food samples representing a Market Basket, which shows dietary habits of a large-scale population. This TDS presents results of the element concentrations, daily dietary intakes and contributions to the total daily intake of essential elements, Na, K, Ca, Fe, Zn and Cr in 30 food groups of a Market Basket of São Paulo State, Brazil. The methodology for the first Brazilian TDS for the São Paulo State population and its respective Market Basket was developed. Food consumption data and information were obtained from the National Household Food Budget Survey, Pesquisa de Orçamentos Familiares (POF) 2002–2003 conducted by the Brazilian Institute for Geography and Statistics, which includes 5440 foods. The selection criteria to carry out the Market Basket were the foods consumed at more than 2 g/day/person, which represented 72% of the total weight of the foods for this population. Element concentrations were determined by instrumental neutron activation analysis and ranged in mg kg⁻¹ as follows: Na: 1.5–256,185; K: 0.51–532; Ca: 22–1827; Fe: 0.08–49; Zn: 0.030–98; and in μg kg⁻¹ Cr: 2.6–799. The dietary intakes contributed by the Market Basket were: 1928 mg/day⁻¹ Na; 861 mg/day⁻¹ K; 275 mg/day⁻¹ Ca; 5.70 mg/day⁻¹ Fe; 4.25 mg/day⁻¹ Zn and 20.7 μg/day⁻¹ Cr. The observed low levels are probably due to the fact that Market Basket represented 72% of the weight of the household consumed foods. The highest contributions to the total intake of the essential elements were: salts, 78.9% of Na; breads, 36.9% of Fe and 46.4% of Cr; cereals, 18.7% of Zn; and milk/cream, 58.7% of Ca and 23.6% of K.     

Elemental (As,Zn, Fe and Cu) analysis and health risk assessment of rice grains and rice based food products collected from markets from different cities of Gangetic basin,India

The present study measured arsenic (As), copper (Cu), zinc (Zn) and iron (Fe) concentrations in grains of different rice varieties and rice based food products collected from various cities located in Gangetic basin in India. Total 44 rice samples were collected from local markets from different locations and analyzed for elemental concentrations by Atomic Absorption Spectroscopy. The results showed that the mean concentration of As, Zn, Cu and Fe were 0.15 ± 0.10, 117 ± 24, 4.6 ± 0.5 and 32.5 ± 5.7 μg g^-1 dw, respectively in rice grains and 0.17 ± 0.09, 193 ± 241, 4.5 ± 1.0 and 45.7 ± 25 μg g^-1 dw, respectively in rice based food products. The hazard quotient (HQ) of As was the lowest in Patna (2.4) and the highest in Kolkata (5.0) but it was always higher than threshold value of one. The carcinogenic risk of the As for rice grains was found to be higher (10^-3) than safe range of 10^-6-10^-4 set by USEPA except Jabalpur. Daily consumption analyses also indicated that consumption of rice and rice products was not sufficient to fulfill daily requirement of Fe in most of the cities. The present results implicate that the consumption of rice and rice products may act as source of As on one hand and may not provide sufficient essential elements on the other.     

Toxic and essential trace element concentrations in the freshwater shrimp Macrobrachium amazonicum in the Lower Amazon,Brazil

This study aimed to evaluate the concentrations of toxic elements (As, Cd, Hg, Pb) and essential trace elements (Co, Cu, Cr, Fe, Mn, Mo, Ni, Se, Zn) in the freshwater shrimp M. amazonicum in the region of Santarem (lower Amazonia), which is affected by mining activities. The level of metal accumulation in the shrimp was found to be similar to that measured in other regions affected by anthropogenic polluted in both in Brazil and elsewhere, and does not pose a significant risk for human consumption. The different patterns of metal accumulation between the Amazon and Tapajos basins appear to be (at least partly) related to respectively bauxite exploitation and gold mining in the region. Bioaccumulation of the trace elements Co, Fe, and Mn mainly occurred in the visceral part of the shrimps from the Amazon river.     

Distribution of essential and non-essential elements in rice located in a Protected Natural Reserve “Marjal de Pego-Oliva”

Anthropogenic agronomic practices could negatively affect the agricultural soil which is the main source for inorganic arsenic (i-As) contamination in rice fields due to flooding. The presence of essential elements could be impacted by food industry units operations. The aim of this study was to evaluate the effect of husking and polishing on mineral essential elements and inorganic As species in rice from Protected Natural Reserve “Marjal de Pego-Oliva”. The amount of all studied elements was significantly affected by husking (a decrease of Ca, Na and Pb, 360 to 101 mg kg⁻¹, 202 to 46.9 mg kg^-1 and 17.9 to 5.70 μg kg⁻¹, respectively) and by polishing (a reduction of Na, Mg, P, K, Ca and Cu, 46.9–26.8 mg kg⁻¹, 1600 to 481 mg kg⁻¹, 4050 to 1530 mg kg⁻¹, 2780 to 882 mg kg⁻¹, 101 to 53.7 mg kg⁻¹, and 3600 to 2840, μg kg⁻¹, respectively).The replacement of white rice (WR) to brown rice (BR) could enhance the daily dietary intake of essential elements to reach the dietary reference values and the maximum i-As (40.9 and 44.9 i-As μg kg^-1 for BR and WR, respectively) was below the maximum level recently established by European Food Safety Agency.     

Determination and chemometric evaluation of the mineral profile of maize flours

Maize flour is a food rich in nutrients important for the proper functioning of the human body. Nevertheless, for the determination of metals in maize flour there are few studies, which raise concern about quality and its mineral composition for consumption. In this work, it was evaluated the concentration of essential (Ca, Cu, Fe, Mn, Mg, Cr and Zn) and non-essential (Cd and Cr) metals in yellow and white maize flour samples produced in Paraná State - Brazil. For this purpose, it was performed a sample treatment employing wet digestion in a digester block and determination of metals by atomic absorption spectrometry (AAS). The highest concentrations found in the flour were Ca (55.4 mg kg⁻¹) and Mg (86.9 mg kg⁻¹) and the lowest concentrations were Cr (0.11 mg kg⁻¹) and Cd (0.01 mg kg⁻¹). In yellow and white maize flour the highest concentration was for Mg, 81.5 mg kg⁻¹and 98.4 mg kg⁻¹, respectively. Principal component analysis (PCA) showed that some samples had a similar mineral profile, such as the relationship with the place of origin of the cereal.     

Assessing arsenic,cadmium, and lead contents in major crops in Brazil for food safety purposes

The food chain is one of the major sources of human exposure to non-essential trace elements (TEs) present in soils. Human exposure to contaminated food is a worldwide health concern and a food safety issue that threatens agricultural trade. To assess the quality of Brazilian food products with respect to non-essential TEs, we evaluated arsenic (As), cadmium (Cd), and lead (Pb) contents in five major crops grown in Brazil: rice, wheat, corn, soybeans, and potatoes. The samples were collected from field trials with a record of long-term use of phosphate fertilizers in the states of Mato Grosso and Minas Gerais, Brazil. The TE concentrations in soils were all bellow the maximum allowable concentrations for agricultural soils. The mean concentrations of As, Cd, and Pb (μg kg⁻¹ dry weight) were as follows: below the detection limit <15, 29, and <40 for rice; 19, 23, and 64 for wheat; 47, 40, and 95 for corn; 65, 23, and 106 for soybeans; and 59, 22, and <40 for potatoes, respectively. Significant differences were found in the As and Cd contents of the different wheat cultivars. The levels of As, Cd, and Pb found in the studied crops are well below the values reported in the literature and are in accordance with the Codex Alimentarius and the European Union and Brazilian guidelines, indicating that the concentrations of these elements in the crops do not pose a risk to human health.     

Element differences and evaluation of the dietary intake from farmed oysters and mussels collected at different sites along the Croatian coast of the Adriatic Sea

Concentrations of the macroelements Ca, Mg, K and Na, microelements Cr, Cu, Fe, Mn and Zn and toxic metals As, Cd, Hg and Pb were determined in oysters and mussels collected at farming sites in the northern, central and south Adriatic Sea. Mean concentrations in oysters were (mg kg⁻¹): As 4.51, Ca 1551, Cd 1.44, Cu 53.6, Cr 0.23, Fe 45.9, Hg 0.047, K 2476, Mg 895, Mn 2.80, Na 7148, Pb 0.52, Zn 675. Mean values in mussels were (mg kg⁻¹): As 4.71, Ca 601, Cd 0.37, Cu 1.91, Cr 0.29, Fe 49.6, Hg 0.026, K 2246, Mg 1043, Mn 2.49, Na 7992, Pb 0.58, Zn 28.8. Significant differences in the concentrations of toxic metals and elements were found in oysters and mussels among farming sites. Obtained Cd, Hg and Pb concentration in oysters and mussels were lower than the limit levels set by the European Community. However, Cd concentration exceeded the limit level of 1 mg kg⁻¹ in oysters from all locations except Lim Bay. The estimated daily intakes (EDIs) indicate that oysters are a good source of Ca, Cu and Zn. The higher Cu and Zn concentrations than the toxicity reference values suggest a risk for consumers if larger quantities of oysters are consumed frequently.     

Essential and non-essential elements in Brazilian infant food and other rice-based products frequently consumed by children and celiac population

Rice and its derivatives are important source of essential and non-essential elements. Essential elements as cobalt (Co) and selenium (Se) are vital for human homeostasis. However, non-essential elements such as arsenic (As), cadmium (Cd) and lead (Pb) may be present in rice-based food and consequently, people can be exposed—especially children and the celiac population. This study aimed to determine essentials and non-essentials elements in rice-based products and baby food and also to evaluate nutritional risk by estimating the daily intake of non-essential elements. Regarding essential elements, Co and Se presented the highest concentrations in rice flour (56 μg kg⁻¹) and porridge (254 μg kg⁻¹), respectively. For non-essential elements, the highest concentrations of As, Cd and Pb were 104 μg kg⁻¹ (porridge), 16 μg kg⁻¹ (flour), and 188 μg kg⁻¹ (bread), respectively. Total As concentration in Brazilian rice-based baby food was <29 μg kg⁻¹. However, As-speciation revealed inorganic-As (i-As) as the main specie. The highest estimated daily intake of Cd, Pb and i-As were 1.37 (rice-based baby food); 10.39 (pasta); and 3.34 (pasta) μg d⁻¹, respectively. Therefore, continuous food monitoring for nutritional and toxicological purpose is necessary, especially concerning these particular populations and discussions for maximum levels of non-essential elements.     

Patterns and Determinants of Essential and Toxic Elements in Chinese Women at Mid-Pregnancy,Late Pregnancy,and Lactation

Maternal status of essential and toxic elements affects the health of the mother, developing fetus, or breastfeeding infant. However, few studies have examined the patterns of these elements and their determinants in pregnant or lactating women. Plasma samples of 1211 healthy mid-pregnant, late pregnant, and lactating women enrolled in coastland, lakeland, and inland areas of China from May–July 2014, were analyzed for concentrations of 15 elements, using inductively coupled plasma mass spectrometry. The adjusted median concentrations of elements varied by physiologic stage and region. Lactating versus pregnant women showed higher concentrations of Zn, Cr, Mo, Ni, Sb, Cd and Pb, but lower concentrations of Cu, I, Al and Hg. In pregnant women, the concentrations of Fe, Zn, I, Mo, Ni, Al, Hg and Cd were higher in mid- versus late-pregnancy. Overall, the highest concentrations were observed in Zn, I, Mn, Al, and Pb in coastland, in Hg in lakeland, and in Fe in inland area. Element concentrations varied by maternal age, pre-pregnancy BMI, education, parity, delivery mode, feeding practice, and intakes of aquatic products and mutton. In conclusion, essential and toxic elements coexisted in pregnant and lactating women, and their concentrations varied by physiologic stages, regions, maternal socio-demographic characteristics and dietary factors.     

“Metals in Fresh Honeys from Tenerife Island, Spain”

Ashes and contents of Zn, Cu, Fe, Cd and Pb in 140 fresh honey samples from three different areas of Tenerife Island were determined by inductively coupled plasma atomic emission spectrometry and graphite furnace atomic absorption spectrometry. A mean ash content of 0.35% has been determined. The mean Fe, Cu, Zn, Pb and Cd concentrations observed have been 3.37 mg kg⁻¹, 1.28 mg kg⁻¹, 2.83 mg kg⁻¹, 37.33 μg kg⁻¹, 4.38 μg kg⁻¹, respectively. A direct statistical correlation has been found between the Fe–Zn and Fe–Pb content, and between the Cd–Zn and Cd–Pb levels.     

Contents of mineral elements in Swedish market basket diets

The aim of this study was to estimate the average dietary exposure to toxic and essential mineral elements in the Swedish population (Cd, Pb, Zn, Cu, Ni, Cr, Fe, Mn, Co, Se, Ca, K, Mg, Na, I). Market baskets were purchased during March-May 1999 in four cities representing the major geographical regions and population centres in Sweden. The market baskets were based on food disappearance data representing more than 90% of annual supply, and were divided into 12 food groups.Large variations between food groups were seen for the average concentrations of most essential elements. Differences between the four cities were relatively small (CoV < 10-20%), exceptions being e.g. Se in cereals and I in meat. Pb concentration varied considerably among food groups ranging from <0.001 mg/kg in soft drinks to 0.027 mg/kg in wine. Cd concentration varied from <0.001 mg/kg in soft drinks and dairy products to 0.024 mg/kg in cereal products. Average contents of the elements were (per/person/day) 1110 mg Ca, 2580 mg Na, 3320 mg K, 285 mg Mg, 11.3 mg Zn, 9.2 mg Fe, 3.5 mg Mn, 1.15 mg Cu, 0.20 mg I, 0.052 mg Se, 0.09 mg Ni, 0.025 mg Cr, 0.011 mg Co, 0.007 mg Pb and 0.010 mg Cd. Compared to a previous study in 1987 no or minor changes in the supply of Ca, Mg, Zn, Mn, Cu and Cd have occurred. The content of Fe was about 40% lower in the present study, mainly due to cessation of flour fortification. The content of Se was about 30% higher. The content of Pb was about 50% lower, probably due to the elimination of Pb from petrol and other measures taken to reduce Pb emissions in Sweden. The average content of essential mineral elements in the Swedish diet was close to or above daily recommended intakes for adults, except for Mg and Fe. The average Pb and Cd content corresponds to 3% and 17% of the JECFA PTWI, respectively. The content of Cd corresponds to 47% of the new TWI established by EFSA in 2009.     

Determination and health risk assessment of heavy metals in imported rice bran oil in Iran

In this current study, the contents of heavy metals including Pb, As, Cr, Cd, Zn, Cu, and Mn in imported rice bran oil in Iran were investigated with microwave digestion method based on an inductively coupled plasma optical emission spectrometry system (ICP-OES). The concentrations range of Pb, Cr, Cd, As, Zn, and Cu in rice bran oil samples were measured as 0.066–0.30, 0.008–0.014, 0.005–0.01, 0.047–0.01, 0.025–0.74 and 0.01–0.096 μg/g, respectively. A significant difference (p-value < 0.05) in the mean concentration of Pb in imported rice bran oils samples was observed. The sum of incremental lifetime cancer risk (ILCR) for heavy metals for children and adults were 2.6 × 10⁻⁴ and 2.4 × 10⁻⁵, respectively, which an acceptable level proposed values (10⁻⁴–10⁻⁶) by U.S. EPA. Moreover, the target hazard quotients (THQs) of As, Pb, Cr, Cd, Cu, and Zn for children were limited to between 1.17 × 10^-5 and 9.49 × 10⁻⁹, and in adults were limited to 2.33 × 10⁻⁷and 6.82 × 10^-7, which were lower than the acceptable limit (THQ < 1). There have been concerns regarding heavy metals since past up to now in all foodstuffs. We demonstrated in this study that there are traceable concentrations of heavy metals in six brand of rice bran oils.     

Trace Element Concentration in Groundwater,Tuticorin City,Tamil Nadu,India

The aim of the present study is to investigate the pollution vulnerability of groundwater aquifers in the coastal regions of Tuticorin city, Tamil Nadu, India. Fourteen samples were analyzed to determine the concentration of trace elements (Pb, Zn, Cd, Hg, Cr and Cu) in the groundwater. Among the total samples six were collected from industrial areas and eight from non-industrial areas of Tuticorin city. The concentration of trace element ranges from 0.01 to 0.19 mg/kg⁻¹ for Pb, from 0.01 to 0.16 mg/kg⁻¹ for Zn, from BDL to 0.21 mg/kg⁻¹ for Cd, from BDL (Below Detection Limit) to 0.023 mg/kg⁻¹ for Hg, from 0.02 to 0.18 mg/kg⁻¹ for Cr and from 0.01 to 0.16 mg/kg⁻¹ for Cu. The trace element concentration in groundwater is higher than the WHO suggested maximum permissible limit except Zn and Cu.     

Determination of inorganic arsenic in Argentinean rice by selective HGAAS: Analytical performance for paddy,brown and polished rice

Inorganic As (iAs) species require strict monitoring in foodstuff due to their toxicity. Rice is of particular concern, with recent legislations establishing limits for these species. In this work we develop a method based on selective hydride generation atomic absorption spectrometry (HGAAS) for the determination of iAs in different types of rice (polish, parboiled, brown and paddy rice). The multivariate design of experiments used for optimization showed interactions between different factors involved in hydride generation. Matrix effects were systematically studied, where the flow rate of the carrier gas proved to be a critical parameter for the minimization of matrix interferences. Nevertheless, matrix-matching was found to be necessary for accurate quantification of paddy rice samples. Comparison of the iAs concentrations obtained by HGAAS and HPLC-ICP-MS showed non-significant differences between the methods. Analysis of 86 rice samples from the province of Entre Ríos showed relatively low concentrations of iAs (<282 μg kg⁻¹ for paddy rice and <120 μg kg⁻¹ for polished rice), regardless of total As concentrations (which ranged from 63 μg kg⁻¹ to 932 μg kg⁻¹), suggesting that the rice analyzed tends to accumulate As in its organic forms.     

Semi-quantitative analysis for selecting Fe- and Zn-dense genotypes of staple food crops

Four semi-quantitative screening methods were developed for plant breeding purposes to identify iron (Fe) and zinc (Zn)-dense genotypes in germplasm, elite lines and early generation progeny. Methods include colour image analysis for Fe and Zn in wheat and rice grains, and spectrophotometric analysis of Fe and Zn in ground flour of rice, wheat, potato, sweet potato and cassava. Staining with 71 mM Perl's Prussian blue solution (PPB) and subsequent image analysis with Adobe Photoshop^® to determine pixel numbers in the stained regions lead to the quantification of Fe. Due to differences in grain size between the genotypes evaluated, correlations between inductively coupled plasma-optical emission spectrophotometry (ICP-OES) Fe and PPB derived Fe were improved by standardizing according to grain weight. The ratio of total blue pixel number (TPN)/total grain weight (TGW) of 21 rice lines correlated (r=0.84, p<0.001) with the Fe concentration derived by ICP-OES. Similarly, a colorimetric method was developed for Zn analysis using 1.56 mM Dithizone (DTZ) solution and subsequent quantification by image analysis with Adobe Photoshop^®. As with the Fe analysis, the ratio of TPN/TGW of 70 wheat lines correlated better with ICP-OES Zn analysis (r=0.82, p<0.001) and successfully separated low and high Zn grain germplasm. Ground polished rice and wheat flour were spectrophotometrically analysed after simple extraction in 0.5 M HCl solution using a modified 2,2′-dipyridyl method for Fe, and a modified Zincon^® method for Zn. These two methods show good correlations with ICP analyses (r=0.93 and 0.92 for Fe and Zn, respectively) and thus can be used for semi-quantitative screening to discriminate between genotypes that are either high or low in Fe or Zn. The more precise ICP-OES and AAS methods could then be used to quantify actual amounts of Fe and Zn in those genotypes identified as Fe- and Zn-dense from the initial screening.     

Metallothionein induction is not involved in cadmium accumulation in the duodenum of mice and rats fed diets containing high-cadmium rice or sunflower kernels and a marginal supply of zinc, iron, and calcium

Rats fed diets with cadmium (Cd) concentrations similar to that found in human diets, and nutritionally marginal with respect to iron (Fe), zinc (Zn), and calcium (Ca) retained 10 times more Cd in the duodenum than rats fed adequate mineral diets. In the current study, 2 experiments were performed to determine the role of intestinal metallothionein (MT) in the accumulation of duodenal Cd, and to determine whether endogenous rice grain Cd is as available as Cd exogenously incorporated into the grain. In Expt. 1, wild-type and MT-null mice were fed 40% rice diets containing marginal or adequate amounts of Fe, Zn, and Ca, and 240 mug Cd/kg. Duodenal Cd was 10 times higher in both wild-type and MT-null mice regardless of their mineral status. In Expt. 2, one group of rats was fed 40% rice diets in which Cd was incorporated into the rice during growth and maturation, and another group was fed 40% rice diets in which Cd was incorporated into the rice during cooking. Each group also was fed either marginal or adequate amounts of Zn, Fe, and Ca. After 5 wk, rats were given a single meal labeled with (109)Cd, and the amount of label retained after 7 d was determined by whole-body counting. Rats with marginal mineral status retained 10 times more (109)Cd than those with adequate status; however, there was no difference between rats fed endogenous or exogenous Cd rice. Although duodenal Cd concentration was 8 times higher in the marginally fed rats, MT concentration was unchanged. These 2 experiments indicate that MT induction is not involved in duodenal Cd accumulation in animals with marginal dietary status of Fe, Zn, and Ca. In addition, they support the hypothesis that marginal deficiencies of Fe, Zn, and Ca, commonly found in certain human populations subsisting on rice-based diets, play an important role in increasing the risk of dietary Cd exposure.     

夏枯草茎微量元素分析

使用灰化法处理样品,火焰原子吸收光谱法测定夏枯草茎中的铬、银、锌、镍、镉、铁、铜的含量。结果表明,除Ag元素未检出外,夏枯草茎的微量元素含量Cr、Zn、Ni、Cd、Fe、Cu分别为4.040、11.824、3.896、0.080、71.92、12.440μg/g,各元素含量Fe>Cu>Zn>Cr>Ni>Cd,加标回收率为98.6%~111.1%,该法测定快速、简单,具有可行性。     

Comparisons and selection of rice mutants with high iron and zinc contents in their polished grains that were mutated from the indica type cultivar IR64

Developing rice varieties biofortified with iron (Fe) and zinc (Zn) is an important strategy to alleviate nutritional deficiencies in developing countries, where polished rice is consumed as the staple food. In this study, the contents of several macro- and micro-minerals in polished rice grains of cultivar IR64 and its 254 sodium azide-induced mutants (M8 generation) were assessed. The results indicated that the contents of potassium, phosphorus, calcium, magnesium, iron, manganese, copper, and zinc varied among the tested mutants. The polished rice grains of mutants M-IR-75 and M-IR-58 accumulated more Fe (28.10 and 27.26 mg kg⁻¹, respectively) than cultivar IR64 (3.90 mg kg⁻¹). Mutant M-IR-75 also produced higher yield (average of 8.65 ton ha⁻¹ over two crop seasons) than cultivar IR64 (average of 7.27 ton ha⁻¹). Mutants M-IR-180, M-IR-49 and M-IR-175 contained more Zn (26.58, 28.95 and 26.16 mg kg⁻¹, respectively) than cultivar IR64 (16.00 mg kg⁻¹), but only mutant M-IR-180 showed a grain yield comparable to cultivar IR64. Thus, the mutant M-IR-75 can be recommended to rice growers to produce Fe-rich rice grains. Additionally, the high-Fe (M-IR-75 and M-IR-58) and high-Zn (M-IR-180, M-IR-49 and M-IR-175) mutants can be used as genetic resources for rice improvement programs.     

Heavy Metal Contamination of Arable Soil and Corn Plant in the Vicinity of a Zinc Smelting Factory and Stabilization by Liming

The heavy metal contamination in soils and cultivated corn plants affected by zinc smelting activities in the vicinity of a zinc smelting factory in Korea was studied. Soils and corn plants were sampled at the harvesting stage and analyzed for cadmium (Cd) and zinc (Zn) concentration, as well as Cd and Zn fraction and other chemical properties of soils. Cd and Zn were highly accumulated in the surface soils (0–20 cm), at levels higher than the Korean warning criteria (Cd, 1.5; Zn, 300 mg kg⁻¹), with corresponding mean values of 1.7 and 407 mg kg⁻¹, respectively, but these metals decreased significantly with increasing soil depth and distance from the factory, implying that contaminants may come from the factory through aerosol dynamics (Hong et al., Kor J Environ Agr 26(3):204–209, 2007a; Environ Contam Toxicol 52:496–502, 2007b) and not from geological sources. The leaf part had higher Cd and Zn concentrations, with values of 9.5 and 1733 mg kg⁻¹, compared to the stem (1.6 and 547 mg kg⁻¹) and grain (0.18 and 61 mg kg⁻¹) parts, respectively. Cd and Zn were higher in the oxidizable fraction, at 38.5% and 46.9% of the total Cd (2.6 mg kg⁻¹) and Zn (407 mg kg⁻¹), but the exchangeable + acidic fraction of Cd and Zn as the bioavailable phases was low, 0.2 and 50 mg kg⁻¹, respectively. To study the reduction of plant Cd and Zn uptake by liming, radish (Raphanus sativa L.) was cultivated in one representative field among the sites investigated, and Ca(OH)₂ was applied at rates of 0, 2, 4, and 8 mg ha⁻¹. Plant Cd and Zn concentrations and NH₄OAc extractable Cd and Zn concentrations of soil decreased significantly with increasing Ca(OH)₂ rate, since it markedly increases the cation exchange capacity of soil induced by increased pH. As a result, liming in this kind of soil could be an effective countermeasure in reducing the phytoextractability of Cd and Zn.