Elevated Levels of Cadmium and Zinc in Paddy Soils and Elevated Levels of Cadmium in Rice Grain Downstream of a Zinc Mineralized Area in Thailand: Implications for Public Health

Simmons, Robert W.; Pongsakul, P.; Saiyasitpanich, D.; Klinphoklap, S.

doi:10.1007/s10653-005-7857-z

Cited by 253 publications

(201 citation statements)

References 30 publications

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“…In general, total metal levels for Cd, Cu, Pb, and Zn in individual samples were highly correlated with correlation coefficients ranging from 0.6 to 0.9 (data not shown). Similar trends of metal levels in soil in paddy fields have been observed by Simmons et al (2005), and the distance within a paddy field to the main inlet of irrigation water is crucial in relation to the metal levels observed in soil. These examples indicate that soil monitoring programs have to consider the heterogeneous nature of metal distribution between and within paddy fields in order to be able to accurately assess human health and ecosystem risks related to metals in soil in industrialized areas like those in the western plains of Taiwan.…”

Section: Soil Properties Across the Paddy Fieldssupporting

confidence: 79%

Characterization of soil heavy metal pools in paddy fields in Taiwan: chemical extraction and solid-solution partitioning

et al. 2009

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Background, aim, and scope Ongoing industrialization has resulted in an accumulation of metals like Cd, Cu, Cr, Ni, Zn, and Pb in paddy fields across Southeast Asia. Risks of metals in soils depend on soil properties and the availability of metals in soil. At present, however, limited information is available on how to measure or predict the directly available fraction of metals in paddy soils. Here, the distribution of Cd, Cu, Cr, Ni, Zn, and Pb in 19 paddy fields among the total, reactive, and directly available pools was measured using recently developed concepts for aerated soils. Solid-solution partitioning models have been derived to predict the directly available metal pool. Such models are proven to be useful for risk assessment and to derive soil quality standards for aerated soils. , and directly available metal pools (0.01 M CaCl 2 ) were determined. Solid-solution partitioning models were derived by multiple linear regressions using an extended Freundlich equation using the reactive metal pool, pH, and the cation exchange capacity (CEC). The influence of Zn on metal partitioning and differences between both sampling events (May/November) were evaluated. Results Total metals contents range from background levels to levels in excess of current soil quality standards for arable land. Between 3% (Cr) and 30% (Cd) of all samples exceed present soil quality standards based on extraction with AR. Total metal levels decreased with an increasing distance from the irrigation water inlet. The reactive metal pool relative to the total metal content is increased in the order Cr << Ni = Zn < Pb < Cu < Cd and ranged from less than 10% for Cr to more than 70% for Cd. Despite frequent redox cycles, Cd, Pb, and Cu appear to remain rather reactive. The methods to determine the reactive metal pool in soils yield comparable results, although the 0.43 M HNO 3 extraction is slightly stronger than HCl and EDTA. The close correlation between these methods suggests that they release similar fractions from soils, probably those reversibly sorbed to soil organic matter (SOM) and clay. The average directly available pool ranged from less than 1% for Cu, Pb, and Cr to 10% for Ni, Zn, and Cd when compared to the reactive metal pool. For Cd, Ni, Zn, and to a lesser extent for Cu and Pb, solid-solution partitioning models were able to explain up to 93% (Cd) of the observed variation in the directly available metal pool. CaCl 2 extractable Zn increased the directly available pool for Ni, Cd, and Cu but not that of Pb and Cr. In the polluted soils, the directly available pool was higher in November compared to that in May. Differences in temperature, rainfall, and changes in soil properties such as pH are likely to contribute to the differences observed within the year. The solid-solution partitioning model failed to explain the variation in the directly available Cr pool, probably because Cr is present in precipitates rather than being adsorbed onto SOM and clay. Despite obvious differences in parent material, source of pollu...

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Section: Soil Properties Across the Paddy Fieldssupporting

confidence: 79%

Characterization of soil heavy metal pools in paddy fields in Taiwan: chemical extraction and solid-solution partitioning

et al. 2009

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“…This map was created using Geographic Information Systems software (Arc GIS version 10.2,ESRI Inc.,Redlands,Calif) In addition, China's rough rice imported from other countries accounted for 1.9 % of the national total yield in 2014, 99 % of which was from Thailand (NBS 2015;Shi 2015). The International Water Management Institute (IWMI) investigated 524 paddy soils in Thailand and found that Cd concentrations were 0.5-284 mg/kg (Simmons et al 2005). Kosolsaksakul et al (2014) stated that paddy fields were severely contaminated by zinc ore extraction in the Mae Tao watershed of northwest Thailand, and Cd contents there ranged from 2.5-87.6 mg/kg.…”

Section: Anthropogenic Pollution Sources Analysismentioning

confidence: 99%

Cadmium (Cd) distribution and contamination in Chinese paddy soils on national scale

Liu

Tian

Jiang

et al. 2016

Environ Sci Pollut Res

154

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Rice is a staple food by an increasing number of people in China. As more issues have arisen in China due to rice contaminated by cadmium (Cd), Cd contamination in arable soils has become a severe problem. In China, many studies have examined Cd contamination in arable soils on a national scale, but little studies have focused on the distribution of Cd in paddy fields. This study explored the spatial pattern of Cd in paddy soils in China, made a preliminary evaluation of the potential risk, and identified the most critically contaminated regions based on the domestic rough rice trade flow. The results showed that Cd concentrations in paddy soils in China ranged from 0.01 to 5.50 mg/kg, with a median value of 0.23 mg/kg. On average, the highest Cd concentrations were in Hunan (0.73 mg/kg), Guangxi (0.70 mg/kg), and Sichuan (0.46 mg/ kg) provinces. Cd concentrations in paddy soils in central and western regions were higher than those in eastern regions, especially the southeastern coastal regions. Of the administrative regions, Cd standard exceedance rate was 33.2 %, and the heavy pollution rate was 8.6 %. Regarding to Cd of paddy soil, soil environmental quality was better in Northeast China Plain than in Yangtze River Basin and southeastern coastal region. Mining activities were the main anthropogenic pollution source of Cd in Chinese paddy soil. Based on rice trade, more of the Chinese population would be exposed to Cd through intake of rice produced in Hunan province. Certain regions that output rice, especially Hunan province, should be given priority in the management and control of Cd contamination in paddy soil.

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“…The cadmium contamination was reported in rice, soil and sediment in around Mae Tao Stream, the main source of water supply for agriculture, which is located at Mae Sot District, Tak Province in the north of Thailand [1], [2]. Mae Tao Stream passes through a zinc rich area where the zinc mining has been actively operated for more than 30 years.…”

Section: Introductionmentioning

confidence: 99%

Water Quality Monitoring and Cadmium Contamination in the Sediments of Mae Tao Stream, Mae Sot District, Tak Province, Thailand

Weeraprapan¹,

Phalaraksh²,

Chantara³

et al. 2015

IJESD

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Elevated Levels of Cadmium and Zinc in Paddy Soils and Elevated Levels of Cadmium in Rice Grain Downstream of a Zinc Mineralized Area in Thailand: Implications for Public Health

Cited by 253 publications

References 30 publications

Characterization of soil heavy metal pools in paddy fields in Taiwan: chemical extraction and solid-solution partitioning

Characterization of soil heavy metal pools in paddy fields in Taiwan: chemical extraction and solid-solution partitioning

Cadmium (Cd) distribution and contamination in Chinese paddy soils on national scale

Water Quality Monitoring and Cadmium Contamination in the Sediments of Mae Tao Stream, Mae Sot District, Tak Province, Thailand

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