Methylated Arsenic Species in Rice: Geographical Variation, Origin, and Uptake Mechanisms

Fang-Jie Zhao*, Yong-Guan Zhu, Andrew A. Meharg

*Corresponding author for this work

Research output: Contribution to journalLiterature reviewpeer-review

162 Citations (Scopus)

Abstract

Rice is a major source of inorganic arsenic (iAs) in the human diet because paddy rice. efficient at accumulating As Rice As speciation is dominated by iAs and dimethylarsinic acid (DMA). Here we review the global pattern in rice As speciation and the factors causing the variation. Rice produced in Asia shows a strong linear relationship between iAs and total As concentration with a slope of 0.78. Rice produced in Europe and the United States shows a more variable, but generally hyperbolic relationship with DMA being predominant in U.S. rice. Although there is significant genotypic variation in grain As speciation, the regional Variations are primarily attributed to environmental factors. Emerging evidence also indicates that methylated. As species in rice are derived from the soil, while rice plants lack the As methylation ability. Soil flooding and additions of organic matter increase microbial methylation of As, although the microbial community responsible for methylafion is poorly understood. Compared with iAs, methylated As species are taken up by rice roots less efficiently but are transported to the grain much, more efficiently, which may be an important factor responsible for the spikelet sterility disorder (straight head disease) in rice. DMA is a weak carcinogen, but the level of ingestion from rice consumption is much lower than that of concern. Questions that require further investigations are identified.

Original languageEnglish
Pages (from-to)3957-3966
Number of pages10
JournalEnvironmental science & technology
Volume47
Issue number9
DOIs
Publication statusPublished - 07 May 2013

Keywords

  • S-ADENOSYLMETHIONINE METHYLTRANSFERASE
  • CONTAMINATED PADDY SOILS
  • ORYZA-SATIVA L.
  • DIMETHYLARSINIC ACID
  • RISK-ASSESSMENT
  • IN-VITRO
  • GLUTATHIONE COMPLEXES
  • HELIANTHUS-ANNUUS
  • WATER MANAGEMENT
  • DIETARY EXPOSURE

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