Health risk assessment of small organoarsenic species in food
(11.07.2024)
The European Commission has asked the European Food Safety Authority (EFSA) for a risk assessment on organoarsenic species in food. EFSA has now presented its scientific opinion on the risk assessment on small organoarsenic species.
Background:
Arsenic, a naturally occurring metalloid, is widely present in the environment. It is classified as a Group 1 human carcinogen by the International Agency for Research on Cancer (IARC) and ranks first among toxicants posing significant potential threats to human health based on known or suspected toxicity. Arsenic toxicity varies significantly among different arsenic species, making it essential to understand these differences for accurate health risk assessments. Major arsenic species include inorganic forms, such as arsenite (iAsIII) and arsenate (iAsV), and various organic forms.
In 2009, the European Food Safety Authority (EFSA) Panel on Contaminants in the Food Chain (CONTAM) issued a Scientific Opinion on arsenic in food. The Opinion concluded that small organoarsenic species like monomethylated arsenic (MMA) and dimethylated arsenic (DMA), as well as complex organoarsenic species like arsenosugars and arsenolipids, could not be fully assessed due to insufficient data. It also determined that the complex organoarsenic species arsenobetaine was not of toxicological concern.
The European Commission requested an updated risk assessment of inorganic arsenic from EFSA in 2024 and an assessment of organoarsenic species in food.
The new scientific opinion on the risk assessment of small organoarsenic species in food:
Small organoarsenic species contain methyl groups but no other organic groups bound to arsenic. Dimethylarsinic acid (DMA(V)) is the most abundant of these species in food, with the highest concentrations found in rice, algae, and seafood. The pentavalent oxo-analogues of these species are stable in food matrices, whereas trivalent and thio-containing forms are less stable, converting readily to their pentavalent forms and slowly to their oxo-analogues, complicating analysis.
Health Risk Assessments:
Dimethylarsinic Acid (DMA(V)): Increased incidence of urinary bladder tumours in rats was identified as the critical endpoint. A Benchmark Dose Lower Confidence Limit (BMDL10) of 1.1 mg DMA(V)/kg body weight (bw) per day (equivalent to 0.6 mg As/kg bw per day) was calculated as a reference point (RP).
Monomethylarsonic Acid (MMA(V)): Decreased body weight resulting from diarrhea in rats was identified as the critical endpoint. A BMDL10 of 18.2 mg MMA(V)/kg bw per day (equivalent to 9.7 mg As/kg bw per day) was calculated as an RP.
For other small organoarsenic species, the toxicological data are insufficient to identify critical effects and RPs, so they could not be included in the risk assessment. Given the incomplete toxicological database for both MMA(V) and DMA(V), the CONTAM Panel concluded that establishing health-based guidance values is not appropriate, and a margin of exposure (MOE) approach should be applied.
Occurrence Data and Exposure Estimates
Occurrence data for small organoarsenic species were available only for MMA and DMA, all reported as pentavalent species. The dataset for dietary exposure estimates included 1260 analytical results for DMA and 988 for MMA, all expressed in whole weight and as μg As/kg.
DMA(V): The highest chronic dietary exposure was estimated for toddlers, with rice and fish meat as the main contributors across population groups.
MMA(V): The highest chronic dietary exposures were for high consumers of fish meat and processed/preserved fish in infants and the elderly, respectively.
Margin of Exposure (MOE) Findings
MMA(V): An MOE of ≥ 500 does not raise a health concern. All MOEs were well above 500 for average and high consumers.
DMA(V): An MOE of 10,000 is considered of low health concern due to its genotoxic and carcinogenic potential. However, MOEs were below 10,000 in many cases across dietary surveys and age groups, particularly for some 95th percentile exposures, raising health concerns.
Recommendations
The CONTAM Panel identified a need for:
Robust, validated analytical methods for determining all small organoarsenic species in food.
Certified reference materials, especially for trivalent and thio-containing small organoarsenic species in products such as rice and seafood.
Occurrence data on small organoarsenic species in breast milk and additional data on foods like rice, fish, seafood, and rice-based infant formulas to improve exposure estimations.
Improved understanding of the human metabolism of small organoarsenic species following ingestion and their health implications.
Toxicological studies on developmental effects and neurotoxicity for MMA(V) and DMA(V) and more toxicity data on other small organoarsenic species.
By addressing these gaps, a more comprehensive health risk assessment for small organoarsenic species in food can be achieved.
The original publication
EFSA Panel on Contaminants in the Food Chain (CONTAM), Dieter Schrenk, Margherita Bignami, Laurent Bodin, James Kevin Chipman, Jesús del Mazo, Bettina Grasl-Kraupp, Christer Hogstrand, Laurentius (Ron) Hoogenboom, Jean-Charles Leblanc, Carlo Stefano Nebbia, Elsa Nielsen, Evangelia Ntzani, Annette Petersen, Salomon Sand, Christiane Vleminckx, Heather Wallace, Lars Barregĺrd, Diane Benford, Eugenia Dogliotti, Kevin Francesconi, Jose Ángel Gómez Ruiz, Hans Steinkellner, Tuuli Tauriainen, Tanja Schwerdtle, Risk assessment of small organoarsenic species in food, EFSA J., 22 (2024) e8844. DOI: 10.2903/j.efsa.2024.8844
Related Studies (newest first):
EFSA CONTAM Panel, D. Schrenk, M. Bignami, L. Bodin, J.K. Chipman, J. del Mazo, B. Grasl-Kraupp, C. Hogstrand, L.R. Hoogenboom, J.C. Leblanc, C.S. Nebbia, E. Nielsen, E. Ntzani, A. Petersen, S. Sand, C. Vleminckx, H. Wallace, L. Barregĺrd, D. Benford, T. Schwerdtle. Update of the risk assessment of inorganic arsenic in food. EFSA J., 22/1(2024) e8488. DOI: 10.2903/j.efsa.2024.8488
EFSA, Scientific report on the chronic dietary exposure to inorganic arsenic. EFSA J., 19/1 (2021) 6380. DOI: 10.2903/j.efsa.2021.6380
EFSA CONTAM Panel, Scientific report of on the dietary exposure to inorganic arsenic in the European population. EFSA J., 12/3 (2014) 3597. DOI: 10.2903/j.efsa.2014.3597