Toxic and micronutrient elements in organic, brown and polished rice in Brazil

Abstract

Concentration levels of As, Cd, Hg, Pb, Tl, Sn, Sb Co, Cu, Mn, Se, Zn, Cr, Ni and Mo in different types of rice cultivated in irrigated fields in Brazil were evaluated. Arsenic, Cd, Pb, Zn, Mn and Cu were found in higher concentrations in brown rice samples, suggesting the prevalence of these elements in the bran. Meanwhile, lower concentrations of Pb, Mo, Cr, Se and Co were found in parboiled rice. Organic rice did not differ of cultivated conventionally rice. Thallium, Hg and Sb were not detected in any rice sample whose limits of detection were 0.7 μg kg⁻¹, 2.5 μg kg⁻¹ and 8 μg kg⁻¹, respectively. The concentrations of the investigated elements were compared with those reported for polished rice and brown rice from other countries, unveiling concentrations in general at the same level for rice produced at non-contaminated sites.

Keywords:

• irrigated rice
• organic rice
• toxic elements
• nutrient elements
• heavy metals

Acknowledgement

The authors are grateful to FAPERGS (Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul) for financial support.