Arsenic and heavy metals in paddy soil and polished

Catena 148 (2017) 92–100

Contents lists available at ScienceDirect

Catena journal homepage: www.elsevier.com/locate/catena

Arsenic and heavy metals in paddy soil and polished rice contaminated by mining activities in Korea Ji Cheol Kwon, Zahra Derakhshan Nejad, Myung Chae Jung ⁎ Department of Energy and Mineral Resources Engineering, Sejong University, Seoul 143-747, South Korea

a r t i c l e

i n f o

Article history: Received 4 November 2014 Received in revised form 17 November 2015 Accepted 5 January 2016 Available online 13 January 2016 Keywords: As and heavy metals Agricultural soil Polished rice Daily intake

a b s t r a c t Rice plays an essential role in Asian sustenance. Moreover, it can take up toxic elements through its roots from contaminated soils, and even its leaves and grain can absorb the elements deposited on the soil surface. Hence in 2010, forty soil and polished rice samples were collected from four representative abandoned metal mining areas in Korea and analyzed for As and heavy metals, including Cd, Cu, Pb and Zn, by atomic absorption spectrometry (AAS). Average levels of As, Cd, Cu, Pb and Zn in agricultural soil samples were 64.4, 2.31, 63.5, 146 and 393 mg kg−1, respectively. In addition, the average content of As, Cd, Cu, Pb and Zn in rice grain grown on the contaminated soils evaluated was 0.247, 0.174, 4.69, 0.804 and 16.8 mg kg−1 (dry weight, DW), respectively. These levels are relatively higher than worldwide averages reported by various researchers. Assuming the average rice consumption of 199 g day−1 by overall households in Korea, the amount of daily intake of As and the heavy metals was estimated. The appraised daily intake of As and Cd from the rice grown in the study areas is up to 50% and 80% of ADI (acceptable daily intake) suggested by the FAO/WHO Joint Food Additive and Contaminants Committee, respectively. Consequently, regular rice consumption grown in soils especially in the mining areas can cause health problems for local residents. © 2016 Elsevier B.V. All rights reserved.

1. Introduction Paddy rice (Oryza sativa L.), especially white rice, is the staple in the diet of various people including Chinese, Japanese, Koreans and the other Asians. Rice is the most common crop grown on agricultural land in Korea, with a total production of 4.2 million tons in 2012, which is 0.6% of the total rice production of the world, which in turn is 696 million tons (Ministry of Agriculture, Food and Rural Affairs and Korea Rural Community Corporation, 2012). Household rice consumption as a staple in Korea, however, decreased year after year, for example from 374 g day−1 in 1970 reduced to 199 g day−1 in 2013 (KOSTAT, 2014). In addition, rice production also decreased from 4.9 million tons in 2002 to 4.2 million tons in 2012. In spite of decreasing production and consumption of rice in Korea, rice still plays essential role as a main meal. Rice cultivated in the polluted paddy soil area can affect health detrimentally. Hereupon, obtaining information about heavy metal concentrations in food products and its consumption as a staple are very important in assessing their human health risk (Zhuang et al., 2009). With advent of the 20th century and its increasing in population, industrialization and urbanization, various kinds of environmental pollutants have been observed. In particular, environmental destruction through toxic elements including As, Cd, Co, Cr, Cu, Hg, Pb, Se and Zn has increased. Environmental pollutants, due to the accumulation of ⁎ Corresponding author. E-mail address: [email protected] (M.C. Jung).

http://dx.doi.org/10.1016/j.catena.2016.01.005 0341-8162/© 2016 Elsevier B.V. All rights reserved.

heavy metals on a serious level in plants, are affecting the food crop quality grown on contaminated areas (Jung, 1995). Meanwhile, absorbency of heavy metals by crop plants grown on contaminated soil can cause deleterious effects on local residents' health, and is one of the concerns in such area. Despite of the increase in population, serious environmental pollution can continuously occur. Therefore, sustainable management of the food quality and even water safety is desperately needed. Abandoned metal mines can be a major contamination source of arsenic and heavy metals in the environment owing to previous mining activities including processing and transportation of ores, release of tailings and waste water around mines (Adriano, 1986). The disposal of mine waste often produces more environmental problems than the mining operations themselves. The pollutants maybe transferred from tailings and waste rock dump to nearby soils by acid mine drainage and/or atmospheric deposition of wind-blown dust, depending on climatic and hydraulic conditions, which determine locations of potentially contaminated areas (Chopin and Alloway, 2007a,b; Batista et al., 2007; López et al., 2008). Thus, As and heavy metals in the vicinity of mining areas are dispersed downstream and nearby agricultural soils due to heavy rainfall or strong winds, and eventually they can be accumulated into water and soil systems (Jung and Thornton, 1997). Furthermore, crop plants grown in contaminated soils contained elevated levels of As and heavy metals. Various studies have been thus undertaken regarding the accumulation and risk assessment of the elements derived from mining activities (Liu et al., 2005a, b; Wang et al., 2005;

J.C. Kwon et al. / Catena 148 (2017) 92–100

Yang et al., 2006; Sipter et al., 2008). Numerous researchers have focused on the assessment of potential health risks for inhabitants in the vicinity of hazardous sites like mining areas (Cui et al., 2004; Sipter et al., 2008; Zheng et al., 2007; Zhuang et al., 2009). Furthermore, several researchers have investigated trace element concentrations in rice grains from various countries including Bangladesh (Meharg and Rahman, 2003; Meharg et al., 2009), Canada (Heitkemper et al., 2001), China (Chen et al., 1999; Liu et al., 2005a,b; Yang et al., 2006; Zeng et al., 2008; Qian et al., 2010; Zhao et al., 2010), India (Roychowdhury et al., 2003; Mondal and Polya, 2008; Pal et al., 2009), Jamaica (Johann et al., 2012), Japan (Shimbo et al., 2001), Korea (Jung et al., 2005), Philippines (Zhang et al., 1998), Sweden (Jorhem et al., 2008), and the USA (Williams et al., 2005, 2007).

93

In spite of the large amount of rice consumption in Korea, only a few studies have been undertaken to discover element concentrations in rice through a nation-wide survey in Korea (Moon et al., 1995; Jung and Thornton, 1997; Jung et al., 2005). Therefore, the present study aimed to investigate As and heavy metal (Cd, Cu, Pb, and Zn) concentrations in paddy soils and rice grains affected from previous mining activities and assess the potential health risks of the inhabitants who consumed locally produced rice. 2. Materials and methods Locations of the four representative abandoned metal mines selected by their extent are shown in Fig. 1, and also general information of

Fig. 1. Map showing the location of the four representative abandoned mines in South Korea.

94


the mines was summarized in Table 1. As shown in the figure and table, the Dalsung Cu–W mine located near Taegu city was one of the largest Cu mines in Korea with production reaching a maximum in the 1960s when rates accounted approximately 5–15% of the total Cu and 3–5% of the total W outputs in the country. The mineralization of the mine can be classified as a hydrothermal breccia-pipe type. The study area is underlain by the Gyoungsang sedimentary formation (MiddleUpper Jurassic era), and the geology around the mine is greatly influenced by volcanic activity. The ore minerals are chalcopyrite (CuFeS2) and wolframite ((Fe,Mn)WO4) with a minor amount of arsenopyrite (FeAsS), bismuthinite (Bi2S3) and pyrite (FeS2). The Yeongdae Au–Ag mine located near Jeonju city was a typical hydrothermal vein type with Au (and Ag) bearing quartz and granite vein. The mine was operated during 1956 to 1966 and stopped in 1968. Production from the mining area reached a maximum in the 1963–1966 when rates accounted for 76% of the total Au. In this area soil capping regarding soil remediation was carried out. In addition, the Munmyung Au–Ag mine was located nearby Youngdeokgun and it is well-known as highly contaminated site due to a tailings dam collapse accident in 2002 by a typhoon. The mine was opened in 1938 and stopped production in 1942 by reaching the maximum production of the Au (17%) in 1939. The mineralization of this mine can be classified as a hydrothermal vein type with conglomerate, sandstone, and shale. The Sambo Pb– Zn–barite mine is located 60 km away from Seoul, was opened in 1945 and stopped production in 1991. At its peak in the 1980s, the mine had produced about 10% of the total Pb production and 10–20% of the total Zn production of Korea. The geology of the mine is underlain by muscovite schist, granitic gneiss, and two mica granites. Samples of surface paddy soils (0–15 cm in depth) were taken in and around the four abandoned metal mines. The samples were disaggregated and air-dried at room temperature for 7 days. The dried soils were carefully ground and sieved to pass through 100 mesh size (b180 μm). The finely ground samples were digested in a ratio of 3:1 concentrated HCl and HNO3 and then filtered to 0.45 μm cellulose acetate membrane filter (Ure, 1995). Arsenic concentrations in the solution were measured by atomic absorption spectrometry (Varian A-240, Australia) attached a hydride generation system after adding KI solution for the reducing process. The other heavy metals were also analyzed by the AAS. A total of forty rice grain samples (10 samples each mine) were taken at the paddy field using stainless steel scissors. The samples were thoroughly washed in de-ionized water prepared by filtration of tap water through a Millipore-Q system (Millipore, France), dried in a clean room at 20 °C for 7 days, and then milled to a fine powder in a stainless steel electric grinder. The prepared grain samples were added to concentrated fuming nitric acid for the removal of organic compounds and then decomposed by aqua regia (3:1 mixing ratio of HCl and HNO3). After filtration, the solution was analyzed for As and heavy metals with the same procedure as the soils. The QA/QC scheme as a certified reference material of rice sample (NCS ZC73008) from National Analysis Center of Iron and Steel (NACIS) in China was used to estimate the recovery of the analysis. Accuracy was determined by comparing the measured concentration with the certified values and was expressed as a percentage recovery (Table 2). The recovery for all elements ranged from 87% to 104%, with the exception of uncertified Pb.

Table 2 Comparison between measured (B) and certified concentration (A) using analytical recovery percentage (B/A) of As, Cd, Cu, Pb and Zn for NCS ZC73008 (rice, China). Element (mg kg−1)

Certified value (A)

Measured value (B)

Recovery (B/A)(%)3

As Cd Cu Pb1 Zn

0.102 ± 0.0082 0.087 ± 0.005 4.9 ± 0.3 0.08 ± 0.03 23 ± 2

0.101 0.080 5.1 0.05 20

99 92 104 63 87

1 2 3

Uncertified value. Mean ± standard deviation. Recovery (%) = {(measured mean value/certified mean value) × 100}.

3. Results and discussion 3.1. Arsenic and heavy metal concentrations in paddy soil and rice grain The range and mean concentrations of As and heavy metals in paddy soils are shown in Table 3. There the evaluated levels of As, Cd, Cu, Pb and Zn were found in the soils with averages of 64.4, 2.31, 63.5, 146 and 393 mg kg−1, respectively. The maximum concentrations of As, Cd, Cu, Pb and Zn in paddy soils were 704, 12.8, 243, 885 and 1600 mg kg−1, respectively. These levels are 2 to 10 times higher than the world average soils compiled by Bowen (1979). In comparison to the national survey of background levels of heavy metals in agricultural soils from various countries, soils from the study areas contained several times higher As and heavy metal concentrations mainly due to previous mining activities (Table 4). The total content of As, Cd, Cu, Pb and Zn in polished rice samples grown on contaminated soils are furnished in Table 5. Although heavy metal concentration can be varied depending upon sampling sites, Zn in the rice grain appropriating the highest concentration and next to Cu. Thus, average values (mg kg− 1, DW) of the elements in the rice decreased on the order of Zn (16.8) N Cu (4.69) N Pb (0.804) N As (0.247) N Cd (0.174). 3.1.1. Arsenic Arsenic as a metalloid is toxic to plants and animals. Anthropogenic activities, such as contaminated irrigation water by mining and smelting industries, have released large amounts of As into paddy soils (Kham et al., 2010). Rice absorbs As more efficiently than other cereals, mainly due to the anaerobic conditions in paddy soils (Williams et al., 2007; Su et al., 2010). Rice grown on As contaminated paddy soils can accumulate elevated levels of As and increase the transfer of it from soil to rice, eventually posing a health risk to consumers (Xie and Huang, 1998; Abedin et al., 2002). Furthermore, the use of arsenic-containing compounds on soils and/ or As contaminated irrigation water appears to be driving force for increasing As concentration in rice grains. It is generally accepted that edible plants grown on uncontaminated or unmineralized soils contain 0.01–1.5 mg As kg−1 (DW) with leafy vegetables being in the upper range and fruits in the lower range (Bowen, 1979). Comparisons of As concentration in rice reported from various countries including Korea as well are shown in Table 6. There As contents in rice grain from world market are in the range of 0.11 to 0.28 mg kg−1 (DW). Jung

Table 1 General information of the four selected metal mines in Korea. Mine name

Mineralization type

Target metal

Bed rocks

Reference

Dalsung Yeongdae Munmyung Sambo

Breccia pipe Hydrothermal vein Hydrothermal vein Hydrothermal vein

Cu, W Au, Ag, Cu, Pb Au, Ag Pb, Zn

Rhyolite, volcanic, ash, tuff Granite Gneiss Muscovite schist, granite gneiss, two mica granite

Jung (1995) KMOE (2013) KMOE (2013) Jung (1995)


95

Table 3 Mean and range of As and heavy metals in paddy soil samples (unit in mg kg−1). Mine name Dalsung mine (N = 10) Yeongdae mine (N = 10) Munmyung mine (N = 10) Sambo mine (N = 10) overall (N = 40)

Range Meana Range Meana Range Meana Range Meana Range Meana

As

Cd

Cu

Pb

Zn

8.95–56.7 26.0 ± 17.8 6.66–71.0 30.2 ± 17.6 22.2–704 196 ± 215 2.85–9.71 5.40 ± 1.98 2.85–704 64.4 ± 130

0.63–3.03 1.78 ± 0.928 0.01–12.8 5.42 ± 4.47 0.416–4.21 1.74 ± 1.29 0.001–1.55 0.298 ± 0.478 0.001–12.8 2.31 ± 2.99

46.7–243 152 ± 80.5 14.7–147 48.0 ± 38.4 16.9–32.9 22.6 ± 5.80 21.7–44.6 31.6 ± 6.57 14.7–243 63.5 ± 67.9

30.1–93.1 50.4 ± 17.1 27.4–885 264 ± 258 54.6–465 214 ± 157 26.3–105 53.4 ± 27.5 26.3–885 146 ± 175

89.7–482 277 ± 144 104–1600 712 ± 496 95.6–670 288 ± 186 131–557 293 ± 135 89.7–1600 393 ± 330

N = number of samples. a = arithmetic mean ± standard deviation.

et al. (2005) also compiled As concentration in rice from various countries and reported that As concentrations in polished rice grown on uncontaminated soils was in the range of 0.04 to 0.20 mg kg−1 (DW). Studies from contaminated sites in China and Japan, however, contained elevated levels of As in rice grain with 0.93 and 1.76 mg kg−1 (DW) influenced by mining activities, respectively. As a result of the chemical analysis shown in Table 5, the As concentration in polished rice was in the range of 0.104 and 0.774 mg kg−1 (DW), with an average of 0.247 mg kg− 1 (DW). This value is lower than the current maximum allowable concentration (MAC) of 0.7 mg As kg−1 (DW) (Huang et al., 2008), while it is higher than data reported by Jung et al. (2005). The total As levels found in this study are the same magnitude as those reported by Pal et al. (2009) of 0.25 mg kg−1 (DW), while they were relatively lower than those reported by Iimura (1981) investigated from mining areas in Japan. Thereupon, the sorting of high concentration of As in rice grains was observed in the Dalsung mine and next to the Sambo mine, while rice grains from the Munmyung and Yeongdae mines represented relatively low As concentrations. Furthermore, it should be considered that not only the As content in soil but also so many different factors (oxides/hydroxide) affect arsenic uptake by rice. The most important factor determining whether arsenic in the soil gets into the plant-based food crops, however, is the genetic makeup of the plant itself. Arsenic and silicon are chemically very similar under the soil conditions found in flooded rice paddies, and as a result, arsenic literally fits into the silicon transporters; it is integrated into the plant as it grows, finding its way into the grain (i.e., associated with sulfides; Conesa et al., 2008). To date, there is neither a clear consensus surrounding the concept of bioavailability, nor is there an exact way of defining it in the context of As. In plants, the bioavailable As fraction would be the amount of As a plant takes up from the soils, although this concept has yet to be measured and cannot be predicted (Fitz and Wenzel, 2006). The available and unavailable fractions of contaminants tend to be in equilibrium within the soil, but any change in environmental factors (pH, Eh, climate, biology, hydrology, organic matter, etc.) or alterations in mineral content (e.g., from dissolution–precipitation; oxidation–reduction; formation of complexes–disassociation; adsorption–desorption) can alter the availability of an element (Mench et al., 2009). This dynamic Table 4 Background or uncontaminated levels of As and heavy metals in surface soils from various countries. Country

China Germany Korea Serbia Spain Whole Europe

Arithmetic mean (mg kg−1)

References

As

Cd

Cu

Pb

Zn

5.60 – 5.30 – – –

– 0.17 0.15 – 0.32 –

6.10 8.00 16.7 28.4 20.3 12.0

15.7 40.0 22.0 2.70 19.7 15.0

34.3 82.0 62.5 61.3 72.2 48.0

Su and Yang (2008) Reimann et al. (2003) KMOE (2013) Skrbic and Cupic (2004) Tume et al. (2011) Salminen et al. (2005)

behavior notwithstanding, the analysis of soils by many methods have produced interesting results when estimating a contaminant's potential plant bioavailability. But this topic is beyond the scope of our research focus. 3.1.2. Cadmium It is generally accepted that Cd is one of the most toxic and mobile elements of the all toxic heavy metals (Zhao et al., 2009, 2010). It can be readily absorbed by rice and transferred to aerial organs where it can accumulate to high levels, possibly entering the food chain (Liu et al., 2005a,b; Qian et al., 2010). Consequently, excessive intake of Cd in the diet may lead to impairment of kidney function and other chronic toxicities (Yeung and Hsu, 2005). In many regions, cultivated rice in paddy soil is heavily exposed to Cd, posing a health hazard to local residents. According to literature surveys, average concentrations of Cd in rice from various countries are summarized in Table 7. Jung (1995) reported Cd concentrations in various crop plants grown on uncontaminated soils lower than 1.0 mg kg− 1 (DW). In Japan, for example, an average Cd concentration of 0.05 mg kg− 1 (DW) in polished rice (n = 1198) was recorded by Shimbo et al. (2001). Other studies also reported the variations of total cadmium content in rice from markets and household areas with the range of 0.02 mg kg− 1 (DW) in the Philippines to 0.08 mg kg−1 (DW) in China, while rice grain grown in contaminated soils were in the range of 0.24 to 0.40 mg kg−1 (DW). In this study, the Cd concentrations in rice grains ranged 0.010 to 0.98 mg kg−1 (DW) with an average of 0.17 mg kg−1 (DW). This average value is higher than the current allowance value of 0.1 mg kg−1 (DW) (Huang et al., 2008), and lower than maximum level for Cd suggested by the European Commission (2002) of 0.24 mg kg−1 (DW) in foodstuff and CODEX standard of 0.4 mg kg−1 (DW) in polished rice (CODEX, 2009). With the exception of rice from the Yeongdae mine contaminated up to 0.34 mg kg−1 (DW), most polished rice samples from the other mines contained relatively low concentrations, ranging from 0.05 to 0.18 mg Cd kg−1 (DW). 3.1.3. Copper Copper is an essential element for plant growth, and yet it is toxic to plants at high concentrations. For instance, Cu concentrations from top vineyard soil and sludge-treated soil can reach up to 1500 mg kg− 1 (Besnard et al., 1999) and 1170 mg kg−1 (Crompton, 1998), respectively. In addition, over 4500 mg kg−1 of Cu in soils was also reported around a Cu–Ni smelter area (Barcan and Kovnatsky, 1998). Thus, elevated levels of Cu in soils may inhibit the growth and development of rice plants. Meanwhile, accumulation of Cu in rice grain is directly related to rice safety. In general, Cu levels in plants grown on uncontaminated soils rarely exceed to 20 mg kg−1 (DW) (Adriano, 1986). As a reference, compiled data for average Cu in rice from various countries are summarized in Table 8. Jung (1995) reported the Cu concentration in rice grain grown in uncontaminated soils at about 10 mg kg−1 (DW). Kabata-Pendias and Mukherjee (2007) also reported the world average Cu concentration in rice of 4.7 mg kg−1 (DW). As illustrated in Table 8,

96


Table 5 Mean and range of As and heavy metals in rice grain samples (unit in mg kg−1 (DW)). Mine name Dalsung mine (N = 10) Yeongdae mine (N = 10) Munmyung mine (N = 10) Sambo mine (N = 10) overall (N = 40)

Range Meana Range Meana Range Meana Range Meana Range Meana

As

Cd

Cu

Pb

Zn

0.212–0.454 0.314 ± 0.087 0.162–0.280 0.218 ± 0.040 0.124–0.442 0.217 ± 0.091 0.104–0.774 0.238 ± 0.195 0.104–0.774 0.247 ± 0.120

0.020–0.120 0.052 ± 0.032 0.060–0.980 0.344 ± 0.316 0.020–0.800 0.180 ± 0.228 0.010–0.320 0.114 ± 0.145 0.010–0.980 0.174 ± 0.228

2.06–4.20 3.02 ± 0.822 2.32–7.12 4.32 ± 1.46 3.48–29.6 7.80 ± 2.01 2.00–7.50 3.63 ± 1.53 2.00–29.6 4.69 ± 4.41

0.180–3.34 1.14 ± 0.967 0.080–1.80 0.748 ± 0.67 0.020–1.29 0.655 ± 0.418 0.010–1.09 0.676 ± 0.358 0.010–3.34 0.804 ± 0.654

7.28–38.0 13.3 ± 8.91 10.3–20.6 15.6 ± 3.48 14.5–33.0 19.8 ± 5.59 12.0–34.1 18.4 ± 6.82 7.28–38.0 16.8 ± 6.75

N = number of samples. a = arithmetic mean ± standard deviation.

average levels of Cu in polished rice collected from markets or fields were 1.65 mg kg− 1 (DW) in Jamaica, 1.96 mg kg−1 (DW) in Korea, 3.09 mg kg−1 (DW) in China, and 3.33 mg kg−1 (DW) in India. On the other hand, studies around mining sites in China revealed elevated Cu levels in rice grains with an average of 7.46 mg kg−1 (DW) (Liu et al., 2005a). In the present study, Cu concentrations in rice grains were in the range of 2.00 to 29.6 mg kg−1 (DW) with an average of 4.69 mg kg−1 (DW). The maximum level of 29.6 mg Cu kg−1 (DW) is much greater than the current maximum allowance level of 10 mg kg−1 (DW) suggested by FAO/WHO (1972). With the exception of rice from the Munmyung mine contaminated up to 7.8 mg Cu kg−1 (DW), the polished rice samples from the other mines contained relatively low concentrations of Cu, ranging from 2.00 to 4.32 mg kg−1 (DW).

3.1.4. Lead Lead has been used worldwide since ancient times for its malleability, resistance to corrosion, and low melting point. In general, Pb concentrations in uncontaminated soil can be expected to range from 30 to 100 mg kg−1 (McLaughlin et al., 1999). With rapid industrialization since the 20th century, however, the inputs of Pb to agricultural soils through the combustion of gasoline containing Pb, the fugitive emissions from nonferrous metal mining activity, widespread uses of fertilizers, herbicides and pesticides, and the additions of sewage sludge to the soil have occurred (Davies, 1990). Furthermore, Mining, smelting, refining, manufacturing, recycling, and disposal of Pb-containing products can release extraordinarily high levels of Pb into air, soil, and water environment. Consequently, Pb ranks the first on the priority list of hazardous substances found at Superfund sites in the United States (i.e., based on its frequent presence at cleanup sites, its toxicity, and its potential for human exposure) (ATSDR, 1992). In general, Pb levels in plants grown on uncontaminated soils rarely exceed to 1.0 mg kg−1 (DW) (Kabata-Pendias and Mukherjee, 2007). As a reference, compiled data for average Pb in rice from various countries

Table 6 Arsenic concentrations in rice grains from various countries (unit in mg kg−1 (DW)). Country

Mean

Sampling

References

Bangladesh Canada China

0.13 0.11 0.14 0.12 0.93 0.28 0.25 0.13 1.76 0.13 0.16 0.26

Market Market Market Market Contaminated site Market Contaminated site Market Contaminated site Household and market Market Market

Meharg et al. (2009) Heitkemper et al. (2001) Meharg et al. (2009) Qian et al. (2010) Liu et al. (2005a) Meharg et al. (2009) Pal et al. (2009) Mondal and Polya (2008) Iimura (1981) Jung et al. (2005) Jorhem et al. (2008) Williams et al. (2005)

France India Japan Korea Sweden U.S.A

are summarized in Table 9. According to the compiled data, average Pb concentrations in rice grain from various countries are in the range of 0.004 mg kg− 1 (DW) in Sweden to 0.014 mg kg−1 (DW) in the Philippines, while rice grown on soils from mining area in China illustrated Pb concentrations in the range of 0.800 to 3.10 mg kg−1 (DW). In this study, Pb concentrations in rice grain ranged from 0.01 to 3.34 mg kg−1 (DW) with a mean value of 0.80 mg kg−1 (DW), which was similar to Liu et al. (2005a). Among the study areas, the maximum Pb concentration in rice grain was found in the Dalsung mine with 3.34 mg kg−1 (DW), which may be due to its mineralization.

3.1.5. Zinc Zinc is the 24th most abundant element in the earth's crust, with an average value of 70 mg kg−1 (Krauskopf, 1979). Zinc is an essential element for plant nutrition (Kochian, 1993; Romheld and Marschner, 1991). Most of the Zn produced globally comes from ores containing Zn sulfide minerals. Zinc ranks fourth among metals of the world in annual consumption behind Fe, Al, and Cu. The zinc content of soils develops from the parent rocks, organic matter contents, soil texture, and pH values. In general, Zn concentrations in crop plants are in the range of 1.2 to 73 mg kg−1 (DW), highest in leafy plants and low in grain and fruit (Kabata-Pendias and Mukherjee, 2007). Various studies investigated Zn concentrations in rice grains from the various countries (Table 10). In general, Zn content in rice grains collected from various public markets was about 20 mg kg−1 (Jung et al., 2005; Johann et al., 2012). In addition, Roychowdhury et al. (2003) and Zhao et al. (2009) also reported Zn concentrations in rice grown in uncontaminated areas about 12.7 and 20.7 mg kg−1 (DW), respectively. However, elevated levels of Zn were found in rice grown on soils from mining sites, with an average of 43.2 mg kg−1 (DW) reported by Liu et al. (2005a). In the present study, Zn content in polished rice was in the range of 7.28 to 38.0 mg kg− 1 (DW) with an average of 16.8 mg kg−1 (DW). With the exception of a few samples directly influenced by contaminated sites, most of rice samples contained similar levels of Zn reported by other studies. Among the four study mines, relatively high Zn concentrations in rice grain was observed in collected samples from the Munmyung and Sambo mines due to their mineralization of bed rocks. Table 7 Cadmium concentrations in rice grains from various countries (unit in mg kg−1 (DW)). Country

Mean

Sampling

References

China

0.08 0.05 0.24 0.40 0.08 0.05 0.04 0.02

Field Market Contaminated site Contaminated site Market Market Household and market Household

Cheng et al. (2006) Qian et al. (2010) Yang et al. (2006) Zeng et al. (2008) Johann et al. (2012) Shimbo et al. (2001) Jung et al. (2005) Zhang et al. (1998)

Jamaican Japan Korea Philippines

J.C. Kwon et al. / Catena 148 (2017) 92–100 Table 8 Copper concentrations in rice grains from various countries (unit in mg kg−1 (DW)).

97

Table 10 Zinc concentrations in rice grains from various countries (unit in mg kg−1 (DW)).

Country

Mean

Sampling

References

Country

Mean

Sampling

References

China

7.46 3.09 3.33 1.65 1.96

Contaminated site Field Field Market Household and market

Liu et al. (2005a,b) Zhao et al. (2010) Roychowdhury et al. (2003) Johann et al. (2012) Jung et al. (2005)

China

43.2 20.7 12.7 16.6 15.6

Contaminated site Field Field Household and market Market

Liu et al. (2005a,b) Zhao et al. (2010) Roychowdhury et al. (2003) Jung et al. (2005) Johann et al. (2012)

India Jamaica Korea

3.2. Daily intake of As and heavy metals Arsenic and heavy metals can be naturally present in food or can enter food as a result of human activities such as industrial and agricultural processes. Although rice is a staple in Korea, in recent years its production has continuously decreased. In addition, the average annual consumption of rice per capita has decreased every year, as well. For instance, rice consumption from 374 g day − 1 in 1970 reach to 199 g day− 1 in 2013 (KOSTAT, 2014). As shown in Fig. 2, rice consumption by local farm household (rural area) and non-farm household (urban area) decreased significantly compared to the total population in Korea (overall). Heavy metals can be harmful to human health when foodstuffs containing them are consumed regularly in the diet. To predict the health effects of consuming contaminated toxic heavy metal compounds through the actual dietary, several allowance levels including PTWI (provisional tolerable weekly intake) and ADI (acceptable daily intake) were established. Based on the results achieved from the present study (milled rice samples obtained), As, Cd, Cu, Pb and Zn intake by rice consumption was calculated according to the following equation: ‐1 Daily intake mg day ‐1 ‐1 Concentrations in rice mg kg ; DW Amount of rice consumption g day ¼ 1000

ð1Þ Computed daily intake of As, Cd, Cu, Pb and Zn through rice consumption in different sites by farm households and nonfarm households is summarized in Table 11. 3.2.1. Daily intake of arsenic No evidence exists that As is essential for plant nutrition, although stimulation of root growth with small amounts of As added in a solution culture has been reported (Liebig et al., 1959). The uptake and translocation of As by plants are also influenced by the source of As (MarcusWyner and Rains, 1982). The effective factors on uptake and accumulation of As by rice plants depend upon cultivars and soil types (affected by phosphorus and sulfur content) (Norton et al., 2009a,b; Ahmed et al., 2011). Daum et al. (2001) indicated that rice grain can accumulate relatively large amounts of As even from uncontaminated or unmineralized sites. Moreover, the bioavailability of As in paddy soil is very important for understanding the variation of As accumulation in rice, which also can be affected by geographic location, soil properties, redox conditions and cropping season (Meharg and Rahman, 2003). Exposure of humans living near hazardous waste sites may involve inhalation of arsenic

India Korea Jamaica

dusts in the air, ingestion of arsenic in water and food, and dermal contact with contaminated soil or water. Arsenic occurs naturally in soils as a result of the weathering of the parent rock, while anthropogenic activity has resulted in the widespread atmospheric deposition of arsenic from the burning of coal and the smelting of non-ferrous metals including copper (O'Neill, 1995). Agricultural practice including the historical use of arsenic-based pesticides and ongoing application of fertilizers, sludge and manures containing arsenic has resulted in the accumulation of arsenic in surface soils (Kabata-Pendias and Mukherjee, 2007). In addition, several surveys of arsenic in rice grain from paddy soils have been undertaken (Duxbury et al., 2003; Zavala and Duxbury, 2008). Although there are several factors governing As uptake by rice, the main factor is concentration of As in soil (Jung et al., 2005). Thus, WHO has set the regulation for As intake at 0.126 mg day−1 based on 60 kg (0.0021 mg kg− 1 body weight per day) body weight in adult (WHO, 2011). The estimated daily intake of As from rice consumption grown in soils from the Dalsung mine equals to 0.058 mg day−1, covering nearly 50% of the As intake allowance level suggested by WHO (Table 11). Furthermore, highest As intake by rice consumption for residents in the Dalsung mine area is estimated to be 0.102 mg day− 1, which is over 90% of allowance by WHO. Similar results also found in the other mining areas, within the range of .04 μg day−1 (the Munmyung mine) to .044 μg day−1 (the Sambo mine). 3.2.2. Daily intake of cadmium There are several factors affecting the absorption of Cd in crop plants including rice. In particular, many studies have concluded that the uptake of Cd by plants was directly affected by Cd bioavailability more than the total metal content (Erwin et al., 2007). Hence, the effect of soil type on Cd absorption in rice must be considered and soil quality standards need to be updated regarding control soil Cd contamination. In addition, the rice varieties as an effective factor in paddy fields should be considered. According to Saito et al. (1977), 22% of residents in Cd polluted areas face health problems, such as low-molecular-weight proteinuria, diabetes and kidney proximal tubular dysfunction. WHO, thus, defined the provisional tolerable daily intake (PTDI) of Cd consumption to be 0.060 mg day−1 (0.001 mg kg−1 body weight per day) for an adult with an average 60 kg body weight (WHO, 2011). Several researches

Table 9 Lead concentrations in rice grains from various countries (unit in mg kg−1 (DW)). Country

Mean

Sampling

References

China

0.80 3.10 0.062 0.002 0.361 0.014 0.004

Contaminated site Contaminated site Market Market Household and market Household Market

Liu et al. (2005a,b) Zeng et al. (2008) Qian et al. (2010) Shimbo et al. (2001) Jung et al. (2005) Zhang et al. (1998) Jorhem et al. (2008)

Japan Korea Philippines Sweden

Fig. 2. Annual rice consumption per capita in South Korea.

98


Table 11 Computed daily intake of As, Cd, Cu, Pb and Zn by consumed rice. Mine

Dalsung

Yeongdae

Munmyung

Sambo

Jung et al. (2005) Guideline (μg day−1) 1 2

Consumer

Farm household Nonfarm household Overall Farm household Nonfarm household Overall Farm household Nonfarm household Overall Farm household Nonfarm household Overall Farm household Nonfarm household Overall

Daily rice consumption (g day−1) 325 197 199 325 197 199 325 197 199 325 197 199 375 244 256 –

Daily intake (mg day−1) As

Cd

Cu

Pb

Zn

0.102 0.062 0.063 0.071 0.043 0.043 0.071 0.043 0.043 0.078 0.047 0.047 0.047 0.031 0.032 0.1261

0.017 0.010 0.010. 0.112 0.068 0.069 0.059 0.036 0.036 0.037 0.023 0.023 0.015 0.010 0.010 0.0601

0.983 0.596 0.601 1.400 0.850 0.858 1.600 0.972 0.982 1.180 0.715 0.723 0.735 0.478 0.502 302

0.369 0.224 0.226 0.243 0.147 0.148 0.213 0.129 0.130 0.220 0.133 0.135 0.135 0.880 0.092 0.2141

4.329 2.624 2.650 5.064 3.069 3.100 6.427 3.896 3.936 5.987 3.630 3.667 6.230 4.050 4.250 601

WHO (2011). FAO/WHO (1972).

were conducted in measuring Cd intake by rice in different countries, for instance, 0.002 mg day−1 in Brazil (Santos et al., 2004)), 0.021 mg day−1 in Japan (Ikeda et al., 2000), and 0.018 mg day−1 in the UK (MAFF, 1998). As estimation of Cd intake by rice analyzed, residents who are regularly consuming locally grown rice around the Yeongdae mine can take in Cd about 2 times of the PTDI, which is 0.06 mg day−1 suggested by WHO (Table 11). Among the studied mines, the minimum Cd consumption (0.0096 mg day−1) was observed in the Dalsung mine, while the Sambo and Munmyung mines showed Cd consumption by rice at around 0.037–0.059 mg day−1, respectively. Those are equal to 61% and 97% of allowance levels suggested by WHO (2011). Although there was no evidence for adverse health effect on Cd toxicity in the area, careful attention is needed for rice intake by the residents. In addition to the other mines studied, elevated levels of Cd intake by rice grown in contaminated soils were also estimated. Therefore, it is strongly recommended that residents who are consuming rice grown on the sites should take care of their health and need periodic medical examination and management program. 3.2.3. Daily intake of copper Copper exists as a widely distributed metal in nature. When Cu concentrations in the human body are over the safe values, health problems like deficiency hypochromic anemia, vomiting, hypotension, coma and jaundice can occur. For this reason, WHO has set provisional maximum tolerable daily intake for Cu of 0.05–0.50 mg kg−1 body weight, which means that an adult with 60 kg is allowed an uptake of 3–30 mg day−1. According to a national survey, daily Cu intake through rice was reported to be 1.20 mg day − 1 in The Netherlands (Ellen et al., 1990), 1.40 mg day− 1 in UK (MAFF, 1998) and 1.00 mg day− 1 in India (Raghunath et al., 2006). Based on the allowance level by FAO/WHO (1972), daily Cu intake in the study area showed values in the normal range. In particular in all four mining areas, the highest Cu intake was illustrated in a farm household area. Although the highest value of Cu intake was estimated in samples from the Munmyung mine, which represented daily intake of Cu of about 1.60 mg day − 1 in farm household area (as highest value) that is equal to 5% of allowance level supposed by FAO/WHO (1972). Furthermore, a rice intake of 0.908 mg day− 1 was obtained overall, which is 3% of the allowance level. Obtained results in the Sambo, Yeongdae and Dalsung mines are approximately the same (in range of 0.668–1.40 mg day − 1). A soil survey in British mining area showed a 5% Cu intake based on WHO, which was equaled to 1.402 mg day− 1 that was higher than observed natural background value in the country.

3.2.4. Daily intake of lead Lead is known as an environmental contamination source which detrimentally affects ecosystems, humans and animals. The soil Pb concentration is toxic to vital plant processes and can vary greatly in different cases, due to the interaction of Pb species by plant and many environmental factors. More than 70% of the consumable Pb in the world was applied to produce lead-acid batteries used in automobiles and industrial machinery (Bingham et al., 2001; Kabata-Pendias and Mukherjee, 2007). Some problems caused by lead toxicity include death by lead poisoning, serious long-term toxicity of the skull accompanied with increasing acute brain disorders (Kokori et al., 1999). A provisional maximum tolerable daily Pb intake was established for adults to be 0.0035 mg kg−1 body weight per day by WHO (2011). So each adult of 60 kg body weight has an allowance of 0.214 mg kg−1 body weight per day of Pb. The results of soils survey showed lead intake at 0.032 mg day − 1 (Ikeda et al., 2000) in China, 0.052 mg day− 1 (Alberti-Fidanza et al., 2003) in Italy, 0.032 mg day− 1 (Raghunath et al., 2006) in India and 0.030 mg day− 1 (MAFF, 1998) in United Kingdom. Considering the highest Pb concentration in the study area of 0.369 mg day− 1 in the Dalsung mine makes clear that it is more than twice the allowance level based on WHO regulations. Obtained results from the Yeongdae, Munmyung and Sambo mines are the same, showing 0.120–0.243 mg day− 1 which is close or over the allowance level. Thus, all these areas are exposed to lead pollution, so people who live around these mining areas should be careful using rice planted there. An investigation of the farming area around mines in the UK showed 0.243 mg day − 1 , which was two times higher intake than a natural background value in the country.

3.2.5. Daily intake of zinc Zinc is an essential trace element in the environment, and it is considered one of the microelements which is used by the human body. Based on WHO regulations, the daily intake of Zn per 60 kg adult weight was expressed 8.4 mg day−1 (Ellen et al., 1990) in The Netherlands, 4.8 mg day− 1 (Santos et al., 2004) in Brazil, and 6.26 mg day−1 (Raghunath et al., 2006) in India. The provisional maximum tolerable daily intake of Zn for an adult at 60 kg body weight was established to be 18 to 60 mg day−1 (0.3 to 1 mg kg−1 body weight per day) based on WHO (WHO, 2011). As a result of this study farm household intake at the Dalsung mine showed lowest Zn intake. Based on WHO regulations, 7% of the allowance intake in the mine was observed which is equal to 4.33 mg day−1, and the Yeongdae and Sambo mines showed approximately the same results


(2.87–5.99 mg day−1). While in the Munmyung mine maximum Zn intake was observed. This value is equaled to 6.43 mg day−1 that was equal to 11% of allowance level based on WHO regulations. In British mine area, allowance intake level of Zn was recorded 8% of the WHO regulation which is 5.06 mg day−1 and seems content was lower than natural background value. As illustrated in Table 11, in all four mine areas daily intake value of zinc is lower than boundary standard range which was obtained from WHO. Overall in farm household area Zn concentration has its higher value. 4. Conclusions Self-planted rice is thought to have the main hazardous effects for local inhabitants who consume rice affected by heavy metals. Generally, the concentration of heavy metals in rice stalks and leaves increased with increasing metal contents in surface soils (P b 0.001) and the rate of increase of metals in the rice varied for each metal. Universally, Cd and Zn allocated a higher intake rate through rice while Cu and Pb showed a lower rate (due to differences in solubility and bioavailability). The combination of using AAS to measure heavy metal concentrations in agricultural samples and investigating PTDI are powerful tools for predicting and protecting against heavy metal contamination in the environment. In this regard, the present study examined the baseline of essential and trace elements in 40 rice grain samples in 4 abandoned mining areas of South Korea in 2010. Results are listed as follows: 1) Comparison between observed data in research area and uncontaminated areas showed that the research area has, in general, higher concentration levels of Zn, As, Cd, Cu, and Pb at about 6, 13, 2, 4, and 6 times, respectively. 2) Average content of As and heavy metals in polished rice demonstrated much higher concentrations than the natural background of the existing research. 3) The daily intake of As and heavy metals in mining areas with the assumption of 199 g as an average value of rice consumption in Korea were investigated. The daily intake of As and Pb taken from rice appeared to be 50 and 80% of the ADI (acceptable daily intake) suggested by FAO/WHO, respectively. In the Yeongdae mine, however, a Cd intake of 30% over the allowance level by WHO was observed. Hence, considering the As, Cd, and Pb pollution of rice intake in these contaminated areas, necessary precautions should be considered. References Abedin, M.J., Cresser, M.S., Meharg, A.A., Feldmann, J., Cotter-Howells, J., 2002. Arsenic accumulation and metabolism in rice (Oryza sativa L). Environ. Sci. Technol. 36, 962–968. Adriano, D.C., 1986. Trace Elements in the Terrestrial Environment. Springer-Verlag, New York Inc (432 pp.). Ahmed, Z.U., Panaullah, G.M., Gauch Jr., H., McCouch, S.R., Tyagi, W., Kabir, M.S., Duxbury, J.M., 2011. Genotype and environment effects on rice (Oryza sativa L.) grain arsenic concentration in Bangladesh. Plant Soil 338, 367–382. Alberti-Fidanza, A., Burini, G., Perriello, G., Fidanza, F., 2003. Trace element intake and status of Italian subjects living in the Gubbio area. Environ. Res. 91, 71–77. ATSDR (Agency for Toxic Substances and Disease Registry), 1992. Lead Toxicity. Dept of Health and Human Services, Atlanta, USA. Barcan, V., Kovnatsky, E., 1998. Soil surface geochemical anomaly around the copper– nickel metallurgical smelter. Water Air Soil Pollut. 103, 197–218. Batista, M.J., Abreu, M.M., Serrano, M., 2007. Biogeochemistry in Neves-Corvo mining area, Iberian pyrite belt, Portugal. J. Geochem. Explor. 92, 159–176. Besnard, E., Chenu, C., Robert, M., 1999. Distribution of copper in champagne vineyards soils, as influenced by organic amendments. Proc. 5th Int. Conf. Biogeochem. Trace Elements, 11–15 July, Vienna, pp. 416–418. Bingham, E., Chorsson, B., Powell, C.H., 2001. Patty's Toxicology. fifth ed. Vol. 2. John Wiley and Sons, New York. Bowen, H.J.M., 1979. Environmental Chemistry of the Elements. Academic Press, New York (333 pp.). Cheng, W.D., Zhang, G.P., Yao, H.G., Wu, W., Xu, M., 2006. Genotypic and environmental variation in cadmium, chromium, arsenic, nickel and lead concentrations in rice grains. J. Zhejiang Univ. Sci. B. 7, 565–571. Chen, H.M., Zheng, C.R., Tu, C., Zhu, Y.G., 1999. Heavy metal pollution in soils in China: status and countermeasures. Ambio 28, 130–134.

99

Chopin, E.I.B., Alloway, B.J., 2007a. Trace element partitioning and soil particle characterisation around mining and smelting areas at Tharsis, Riotinto and Huelva, SW Spain. The Science of the Total Environment. 373, pp. 488–500 (d). Chopin, E.I.B., Alloway, B.J., 2007b. Distribution and mobility of trace elements in soils and vegetation around the mining and smelting areas of Tharsis, Riotinto and Huelva, Iberian Pyrite Belt, SW Spain. Water Air Soil Pollut. 182, 245–261. CODEX, 2009. General standard for contaminants and toxins in food and feed. Codex Standard 193-1995. Conesa, H.M., Robinson, B.H., Schulin, B., Nowack, B., 2008. Metal extractability in acidic and neutral mine tailings from the Cartagena–La Unión Mining District (SE Spain). Appl. Geochem. 23, 1232–1240. Crompton, T.R., 1998. Occurrence and Analysis of Organometallic Compounds in the Environment. John Wiley & Sons, Chichester, pp. 250–258. Cui, Y.J., Zhu, Y.G., Zhai, R.H., Chen, D.Y., Huang, Y.Z., Qiu, Y., Liang, Z.L., 2004. Transfer of metals from soil to vegetables in an area near a smelter in Nanning, China. Environ. Int. 30, 785–791. Daum, D., Bogdan, K., Schenk, M.K., Merkel, D., 2001. Influence of the field water management on accumulation of arsenic and cadmium in paddy rice. Dev. Plant Soil Sci. 92, 290–291. Davies, B.E., 1990. In: BJ, A. (Ed.), Heavy Metals in Soils. Blackie and Son, Glasgow, UK, pp. 177–196. Duxbury, J.M., Mayer, A.B., Lauren, J.G., Hassan, N., 2003. Food chain aspects of arsenic contamination in Bangladesh: effects on quality and productivity of rice. J. Environ. Sci. Health, part A:toxic/hazard subst. Environ. Eng. 38, 61–69. Ellen, G., Egmond, E., Van Loon, J.W., Saherhiand, E.T., Tolsma, K., 1990. Dietary intakes of some essential and non-essential trace elements, nitrate, nitrite and N-nitrosoamines by Dutch adults estimated via a 24 h duplicate portion study. Food Addit. Contam. 7, 221. Erwin, J., Kalis, J., Erwin, J., Temminghoff, M., Visser, A., Willem, H., 2007. Metal uptake by Lolium perenne in contaminated soils using a four-step approach. Environ. Toxicol. Chem. 26, 335–345. European Commission, Commission Regulation, 2002. Setting Maximum Levels for Certain Contaminants in Foodstuffs No. 466/2001. FAO/WHO, 1972. Evaluation of certain food additives and of the contaminants mercury, lead and cadmium. Sixteenth report of the joint FAO/WHO expert committee of food additives. World Health Organization Geneva (4–12 April 1972). Fitz, W.J., Wenzel, W.W., 2006. Sequestration of Arsenic by Plants. In: Naidu, R., et al. (Eds.), Managing Arsenic in the Environment. From soils to human health. CSIRO Pub, Collingwood, Australia, pp. 209–222. Heitkemper, D.T., Vela, N.P., Stewart, K.R., Westphal, C.S., 2001. Determination of total and speciated arsenic in rice by ion chromatography and inductively coupled plasma mass spectrometry. J. Anal. At. Spectrom. 16, 299–306. Huang, M., Zhou, S., Sun, B., Zhao, Q., 2008. Heavy metal in wheat grain: assessment of potential health risk for inhabitants in Kunshan, China. Sci. Total Environ. 405, 54–61. Iimura, K., 1981. In: Kitagishi, K., Yamane, I. (Eds.), Heavy metal problems in paddy soils. “Heavy Metal Pollution in Soils of Japan”. Japan Scientific Societies Press, Tokyo, pp. 37–50. Ikeda, M., Zhang, Z.M., Shimbo, S., Watanabe, T., Nakatsuka, H., Moon, C.S., 2000. Urban population exposure to lead and cadmium in east and south-east Asia. Sci. Total Environ. 249, 373–384. Johann, M.R., Antoine, L.A., Fung, H., Grant, C.N., Dennis, H.T., Lalor, G.C., 2012. Dietary intake of minerals and trace elements in rice on the Jamaican market. Food Compos. Anal. 26, 111–121. Jorhem, L., Astrand, C., Sundstrom, B., Baxter, M., Stokes, P., Lewis, J., 2008. Elements in rice from the Swedish market: 1. Cadmium, lead and arsenic(total and inorganic). Food Addit. Contam. 25, 284–292. Jung, M.C., 1995. Environmental contamination of heavy metals in soils, plants, waters and sediments in the vicinity of metalliferous mine in Korea (Ph.D. thesis) University of London (455 pp.). Jung, M.C., Thornton, I., 1997. Environmental contamination and seasonal variation of metals in soils plants and waters in the paddy fields around a Pb–Zn mine in Korea. Sci. Total Environ. 198, 105–121. Jung, M.C., Yun, S.-T., Lee, J.-S., Lee, J.-U., 2005. Baseline study on essential and trace elements in polished rice from South Korea. Environ. Geochem. Health 27, 455–464. Kabata-Pendias, A., Mukherjee, A.B. 2007. Trace Elements from Soil to Human. New York Springer-Verlag Berlin Heidelberg, (550 pp.). Kham, M.A., Stroud, J.L., Zhu, Y.G., McGrath, S.P., Zhao, F.J., 2010. Arsenic bioavailability to rice is elevated in Bangladeshi paddy soils. Environ. Sci. Technol. 44, 8515–8521. KMOE(Korea Ministry of Environment), 2013. Detailed Survey for Soil and Water Contamination in Abandoned Metal Mines in Korea. KMOE, Sejong-City, South Korea (in Korean). Kochian, L.V., 1993. Zinc absorption from hydroponic solutions by plant roots. In: Robson, A.D. (Ed.), Zinc in soils and plants. Kluwer, Dordrecht, The Netherlands, pp. 45–57. Kokori, H., Giannakopoulou, C.H., Hatzidaki, E., Athanaselis, S., Tsatsakis, A., Sbyrakis, S., 1999. An unusual case of lead poisoning in and infant: nursing-associated plumbism. J. Lab. Clin. Med. 134, 522–525. KOSTAT (Statistics Korea), 2014. http://kostat.go.kr. Krauskopf, K.B., 1979. Introduction to Geochemistry. third ed. McGraw-Hill, New York. Liebig, G.F., Bradford, G.R., Vanselow, A.P., 1959. Effects of arsenic compounds on citrus plants in solution culture. Soil Sci. 88, 342–348. Liu, H., Probst, A., Liao, B., 2005a. Metal contamination of soils and crops affected by the Chenzhou lead/zinc mine spill (Hunan, China). Sci. Total Environ. 339, 153–166. Liu, J., Zhu, Q., Zhang, Z., Xu, J., Yang, J., Wong, M.H., 2005b. Variations in cadmium accumulation among rice cultivars and types and the selection of cultivars for reducing cadmium in the diet. J. Sci. Food Agric. 85, 147–153.

100


López, M., González, I., Romero, A., 2008. Trace elements contamination of agricultural soils affected by sulphide exploitation (Iberian Pyrite Belt, SW Spain). Environmental Geology 54, 805–818. MAFF, 1998. Ministry of Agriculture, Fisheries and Food (MAFF) steering group on chemical aspects of food surveillance: survey of lead, arsenic and other metals in food. Food Surveillance Information Sheet, Paper No. 52. HMSO, London (1998). Marcus-Wyner, L., Rains, D.W., 1982. Uptake, accumulation, and translocation of arsenical compounds by cotton. J. Environ. Qual. 11, 715–719. McLaughlin, M.J., Parker, D.R., Clarke, J.M., 1999. Metals and micronutrients-food safety issues. Field Crop Res. 60, 143–163. Meharg, A.A., Rahman, M.M., 2003. Arsenic contamination of Bangladesh paddy field soils: implications for rice contribution to arsenic consumption. Environ. Sci. Technol. 37 (2), 229–234. Meharg, A.A., Williams, P.N., Adomako, E., Lawgali, Y.Y., Deacon, C., Villada, A., Cambell, R.C.J., Sun, G., Zhu, Y.-G., Feldmann, J., Raab, A., Zhao, F.-J., Islam, R., Hossain, S., Yana, J., 2009. Geographical variation in total and inorganic arsenic content of polished (white) rice. Environ. Sci. Technol. 43, 1612–1617. Mench, M., Schwitzguébel, J.P., Schroeder, P., Bert, V., Gawronski, S., Gupta, S., 2009. Assessment of successful experiments and limitations of phytotechnologies: contaminant uptake, detoxifi cation, and sequestration, and consequences to food safety. Environ. Sci. Pollut. Res. Int. 16, 876–900. Ministry of Agriculture, Food and Rural Affairs and Korea Rural Community Corporation, 2012. Statistical yearbook of land and water development for agriculture. Mondal, D., Polya, D.A., 2008. Rice is a major exposure route for arsenic in Chakdaha block, Nadia district, West Bengal, India: a probabilistic risk assessment. Appl. Geochem. 23, 2987–2998. Moon, C.S., Zhang, Z.W., Shimbo, S., Watanabe, T., Moon, D.H., Lee, C.U., Lee, B.K., Ahn, K.D., Lee, S.H., Ikeda, M., 1995. Dietary intake of cadmium and lead among the general population in Korea. Environ. Res. 71, 46–54. Norton, G.J., Islam, M.R., Deacon, C.M., Zhao, F.J., Stroud, J.L., McGrath, S.P., Islam, S., Jahiruddin, M., Feldmann, J., Price, A.H., Meharg, A.A., 2009a. Identification of low inorganic and total grain arsenic rice cultivars form Bangladesh. Environ. Sci. Technol. 43, 6070–6075. Norton, G.J., Duan, G., Dasgupta, T., Islam, M.R., Lei, M., Zhu, Y.G., Deacon, C.M., Moran, A.C., Islam, S., Zhao, F.J., Stroud, J.L., McGrath, S.P., Feldmann, J., Price, A.H., Meharg, A.A., 2009b. Environmental and genetic control of arsenic accumulation and speciation in rice grain: comparing a range of common cultivars crown in contaminated sites across Bangladesh, China, and India. Environ. Sci. Technol. 43, 8381–8386. O'Neill, P., 1995. Arsenic. In: BJ, A. (Ed.), Heavy Metals in Soils, second ed. Blackie Academic and Professional, Glasgow, pp. 105–121. Pal, A., Chowdhury, U.K., Mondal, D., Das, B., Nayak, B., Ghosh, A., Maity, S., Chakraborti, D., 2009. Arsenic burden from cooked rice in the populations of arsenic affected and nonaffected areas and Kolkata city in West-Bengal, India. Environ. Sci. Technol. 43, 3349–3355. Qian, Y.Z., Chen, C., Zhang, Q., Chen, Z., Li, M., 2010. Concentrations of cadmium, lead, mercury and arsenic in Chinese market milled rice and associated population health risk. Food Control 21, 1757–1763. Raghunath, R., Tripathi, R.M., Suseela, B., Bhalke, S., Shukla, V.K., Puranik, V.D., 2006. Dietary intake of metals by Mumbai adult population. Sci. Total Environ. 356, 62–68. Reimann, C., Siewers, U., Tarvainen, T., Bityukova, L., Erikson, A., Gilucis, V., Gregorauskiene, V., Lukasev, V.K., Matinian, N.N., Pasieczna, A., 2003. Agricultural soils in Northern Europe: a geochemical atlas. Geologisches Jahrbuch Sonderhefte. Reihe D Heff SD5, Stuttgart (ISBN 3–510-95906-X). Romheld, V., Marschner, H., 1991. Function of micronutrients in plants. In: Mortvedt, J.J., Cox, F.R., Shuman, L.M., Welch, R.M. (Eds.), Micronutrients in Agriculture. Soil Science Society of America, Book Series No. 4, pp. 297–328 (Madison, USA, pp. 297–328). Roychowdhury, T., Tokunaga, H., Ando, M., 2003. Survey of arsenic and other heavy metals in food composites and drinking water and estimation of dietary intake by the villagers from an arsenic-affected area of West Bengal, India. Sci. Total Environ. 308, 15–35. Saito, H., Shioji, R., Hurukawa, Y., Nagai, K., Arikawa, T., Sasaki, Y., Furuyama, T., Yoshinaga, K., 1977. Cadmium-induced proximal tubular dysfunction in a cadmium-polluted area. Nephrology 6, 1–12. Salminen, R., Batista, M.J., Bdovec, M., Demetriades, A., De Vivo, B., De Vos, W., Duris, M., Gilucis, A., Gregorauskiene, V., Halamic, J., Heitzmann, P., Lima, A., Jordan, G., Klaver, G., Klein, P., Lis, J., Locutura, J., Marsina, K., Mazreku, A., O'Connor, P.J., Olsson, S.A.,

Ottesen, R.T., Petersell, V., Plant, J.A., Reeder, S., Salpeteur, I., Sandstrom, H., Siewers, U., Steenfelt, A., Tarvainen, T., 2005. Geochemical atlas of Europe. Part 1. Background Information, Methodology and Maps. Geological Survey of Finland. Monografija (ISBN: 951–690-921-3). Santos, E.E., Lauria, D.C., Porto, D.A., Silveira, C.L., 2004. Assessment of daily intake of trace elements due to consumption of foodstuffs by adult inhabitants of Rio de Janeiro city. Sci. Total Environ. 327, 69–79. Shimbo, S., Zhang, Z.W., Watanabe, T., Nakatsuka, H., Naoko, M.I., Higashikawa, K., Ikeda, M., 2001. Cadmium and lead contents in rice and other cereal products in Japan in 1998–2000. Sci. Total Environ. 281, 165–175. Sipter, E., Rozsa, E., Gruiz, K., Tatrai, E., Morvai, V., 2008. Site specific risk assessment in contaminated vegetable gardens. Chemosphere 71, 1301–1307. Skrbic, B., Cupic, S., 2004. Trace metal distribution in surface soils of Novi sad and bank sediment of the Danube river. J. Environ. Sci. Health 39, 1547–1558. Su, Y.Z., Yang, R., 2008. Background concentrations of elements in surface soils and their changes as affected by agriculture use in the desert–oasis ecotone in the middle of Heihe River Basin, North-west China. J. Geochem. Explor. 98, 57–64. Su, Y.H., McGrath, S.P., Zhao, F.J., 2010. Rice in more efficient in arsenite uptake and translocation than wheat and barley. Plant Soil 328, 27–34. Tume, P., Bech, J., Reverter, F., Bech, J., Longan, L., Tume, L., Sepulveda, B., 2011. Concentration and distribution of twelve metals in Central Catalonia surface soils. J. Geochem. Explor. 109, 92–103. Ure, A.M., 1995. Methods of analysis for heavy metals in soils. Blackie and Son, Glasgow (58-102 pp.). Wang, X.L., Sato, T., Xing, B.S., Tao, S., 2005. Health risks of heavy metals to the general public in Tianjin, China via consumption of vegetables and fish. Sci. Total Environ. 350, 28–37. WHO, 2011. Joint FAO/WHO food standards programme codex committee on contaminants in foods. Fifth Session. The Hague, The Netherlands (21–25 March 2011). Williams, P.N., Price, A.H., Raab, A., Hossain, S.A., Feldmann, J., Meharg, A.A., 2005. Variation in arsenic speciation and concentration in paddy rice related to dietary exposure. Environ. Sci. Technol. 39, 5531–5540. Williams, P.N., Villada, A., Raab, A., Figuerola, J., Green, A.J., Feldmann, J., Meharg, A.A., 2007. Greatly enhanced arsenic shoot assimilation in rice leads to elevated grain levels compared to wheat and barley. Environ. Sci. Technol. 41, 6854–6859. Xie, Z.M., Huang, C.Y., 1998. Control of arsenic toxicity in rice plants grown on an arsenicpolluted paddy soil. Commun. Soil Sci. Plant Anal. 29, 2471–2477. Yang, Q.W., Lan, C.Y., Wang, H.B., Zhuang, P., Shu, W.S., 2006. Cadmium in soil-rice system and health risk associated with the use of untreated mining wastewater for irrigation in Lechang, China. Agric. Water Manag. 84, 147–152. Yeung, A.T., Hsu, C.N., 2005. Electrokinetic remediation of cadmium contaminated clay. J. Environ. Eng. 131, 298–304. Zavala, Y.J., Duxbury, J.M., 2008. Arsenic in rice: I. Estimating normal levels of total arsenic in rice grain. Environ. Sci. Technol. 42, 3856–3860. Zeng, F.R., Mao, Y., Cheng, W.D., Wu, F.B., Zhang, G.P., 2008. Genotypic and environmental variation in chromium, cadmium and lead concentrations in rice. Environ. Pollut. 153, 309–314. Zhang, Z.W., Subida, R.D., Agetano, M.G., Nakatsuka, H., Inoguchi, N., Watanabe, T., Shimbo, S., Higashikawa, K., Ikeda, M., 1998. Non-occupational exposure of adult women in Manila, the Philippines, to lead and cadmium. Sci. Total Environ. 215, 157–165. Zhao, K., Zhang, W., Zhou, L., Liu, X., Xu, J., Huang, P., 2009. Modeling transfer of heavy metals in soil-rice system and their risk assessment in paddy fields. Environ. Earth Sci. 59, 519–527. Zhao, K., Liu, X., Xu, J., Selim, H.M., 2010. Heavy metal contaminations in a soil-rice system: identification of spatial dependence in relation to soil properties of paddy fields. J. Hazard. Mater. 181, 778–787. Zheng, N., Wang, Q., Zheng, D., 2007. Health risk of Hg, Pb, Cd, Zn, and Cu to the inhabitants around Huludao Zinc plant in China via consumption of vegetables. Sci. Total Environ. 383, 81–89. Zhuang, P., McBride, M.B., Xia, H.P., Li, N.Y., Li, Z.A., 2009. Health risk from heavy metals via consumption of food crops in the vicinity of Dabaoshan mine, South China. Sci. Total Environ. 407, 1551–1561.