Cadmium Content of Commercial and Contaminated Rice, Oryza sativa, in Thailand and Potential Health Implications

Abstract

Thailand is the number one global exporter and among the top five producers of rice in the world. A significant increase in anthropogenic contamination in agricultural soils over the past few decades has lead to concerns with cadmium and its uptake in rice. The cadmium levels in Thai rice from different sources/areas were determined and used to estimate the potential health risks to consumers. The cadmium concentration in the commercial rice samples ranged from below the detection limit to 0.016 mg/kg. The cadmium concentrations in the contaminated rice samples ranged from a low of 0.007 mg/kg to a high of 0.579 mg/kg. Five of the calculated values exceed the proposed PTWI, with one value almost three times higher and two values almost double. The three highly elevated values are certainly a concern from a health standpoint. Ultimately, action is required to address the health implications resulting from the cadmium contamination in agricultural soils used for rice production in a few select areas of Thailand. Overall, this study indicates that the vast majority of rice produced, consumed and exported by Thailand is safe pertaining to cadmium content.

Cadmium in Rice: Disease and Social Considerations

“…Rice has been identified as the major source of the Cd intake, which caused the itai-itai disease in Japan in the mid-20th century (Jahed Khaniki and Zazoli, 2005). In recent years, in part because Cd is found in the rice, a statistically significant correlation between dietary Cd intake and disease has been found in Thailand (Zwicker et al, 2009). Indeed, the importance of rice in human diets throughout the world makes rice contamination by Cd a global environmental health concern.…”

Concentrations of cadmium, lead, mercury and arsenic in Chinese market milled rice and associated population health risk

“…However, each report provides a limited geographical value and some results were referred only in the cases of ten or more samples. It should be stated that the substantial variation commonly existed among the different cities (Simmons, Pongsakul, Saiyasitpanich, & Klinphoklap, 2005;Simmons, Noble, Pongsakul, Sukreeyapongse, & Chinabut, 2008;Zwicker, Promsawad, Zwicker, & Laoharojanaphand, 2010), even among the different locations within the same area due to the large difference in the number of sampling sites and survey scales, even in the degree of milled processing (Cheng et al, 2006).…”

Cadmium Exposure and Potential Health Risk from Foods in Contaminated Area, Thailand

“…The Cd concentrations in most contaminated rice samples were very close to the limit, and only one exceeded the limit. However, because of high consumption as a staple food, 6 in 11 values of the Cd intake from contaminated rice exceed the proposed PTMI 0.025 mg/kg BW ( 35 ).…”