Arsenic species in rice and rice-based products consumed by toddlers in Switzerland

ABSTRACT

Inorganic arsenic (iAs) is a contaminant present in food, especially in rice and rice-based products. Toxicity of arsenic compounds (As) depends on species and oxidative state. iAs species, such as arsenite (As(III)) and arsenate (As(V)), are more bioactive and toxic than organic arsenic species, like methylarsonic acid (MMA(V)) and dimethylarsinic acid (DMA(V)) or arsenosugars and arsenobetaine. An ion chromatography-inductively coupled-plasma-mass spectroscopy method was developed to separate the four following arsenic anions: As(III), As(V), MMA(V) and DMA(V). Sample preparation was done in mild acidic conditions to ensure species preservation. The predominant arsenic species found in rice and rice-based products, except for rice drinks, was As(III), with 60–80% of the total As content, followed by DMA(V) and As(V). MMA(V) was measured only at low levels (<3%). Analyses of rice products (N = 105) intended for toddlers, including special products destined for infants and toddlers, such as dry form baby foods (N = 12) or ready-to-use form (N = 9), were done. It was found in this study that there is little or no margin of exposure. Risk assessment, using the occurrence data and indicated intake scenarios compared to reference BMDLs as established by EFSA, demonstrated toddlers with a high consumption of rice based cereals and rice drinks are at risk of high iAs exposure, for which a potential health risk cannot be excluded.

KEYWORDS:

• IC-ICP-MS
• arsenic speciation
• rice-based baby foods
• risk assessment
• exposure assessment

Acknowledgements

The authors are grateful to Vincent Dudler (Division of Risk Assessment, Federal Food Safety and Veterinary Office) for his scientific expertise and valuable support during the whole study, Liz Stalder (Division of Risk Assessment, Federal Food Safety and Veterinary Office) for her interest in the manuscript and valuable remarks and Lucia Klauser (Division of Food and Nutrition, Federal Food Safety and Veterinary Office) for her valuable expertise on risk management.

Disclosure statement

No potential conflict of interest was reported by the authors.