PLS: Risk assessment of complex organoarsenic species in food

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Disclaimer

  • This plain language summary (PLS) is a simplified communication of EFSA’s Risk assessment of complex organoarsenic species in food. The full EFSA opinion can be found here.
  • The purpose of the PLS is to enhance transparency and inform interested parties on EFSA’s work on the topic using simplified language to present a summary of the main findings.

Background to the risk assessment

  • Risk managers need scientific guidance on the safety of food contaminants, such as arsenic, to establish maximum levels that can be present in foods without causing adverse health effects.
  • Complex organoarsenic species are compounds containing methyl groups and a larger organic group bound to arsenic. These compounds are found almost exclusively in marine foods such as fish, crustaceans, molluscs and seaweeds. The most common complex organoarsenic species include arsenobetaine, arsenosugars (such as glycerol arsenosugar) and arsenolipids.
  • In 2009, the EFSA Panel on Contaminants in the Food Chain (CONTAM Panel) assessed the risks to human health from arsenic in food and published a scientific opinion.
  • At that time, EFSA could only assess the risks of inorganic arsenic due to a lack of data on small and complex organoarsenic species.
  • Since the 2009 scientific opinion, new studies have emerged on the toxicity of both inorganic arsenic and organoarsenic species. Additionally, EFSA released dietary exposure assessments for inorganic arsenic in 2014 and 2021.

What was EFSA asked to do?

  • The European Commission (EC) asked EFSA to provide three risk assessments of arsenic in food, taking into consideration the new scientific information available since 2009:
    • The updated risk assessment for inorganic arsenic in food was published in January 2024.
    • The risk assessment for small organoarsenic species in food was published in July 2024.
    • The risk assessment for complex organoarsenic species is covered by this third scientific opinion.

How did EFSA carry out this work and what data were used?

  • EFSA first commissioned a comprehensive review of the relevant literature on the occurrence and toxicity of organoarsenic species in food, published between 2009 and 2024 and, in some cases, extending to earlier periods. This review (Licht et al., 2022) was a starting point for the present scientific opinion.
  • Additional literature searches were conducted following established protocols.
  • Consumer dietary exposure was estimated from the occurrence and consumption data available at EFSA. In cases where no occurrence data were available, data from the public literature were considered.

What were the outcomes and their implications?

Outcomes for arsenobetaine:

  • A reference point (RP) could not be established due to insufficient data.
  • Arsenobetaine did not show adverse effects in the two available repeat dose toxicity tests in rodents. It has not shown genotoxicity in in vitro assays. There is no indication of an association with adverse outcomes in human studies.
  • High consumers of fish, seafood and fish-based processed foods could be exposed to levels of arsenobetaine corresponding to 12.5 micrograms of elemental arsenic[1] per kilogram of body weight per day.
  • Despite not having an RP, the CONTAM Panel compared the highest dietary exposure to arsenobetaine with the highest no-observed-adverse-effect levels (NOAELs) from the available toxicity tests. This resulted in margins of exposure (MOEs) ranging from 340 to 31,000, not raising a health concern.

Outcomes for glycerol arsenosugar:

  • An RP corresponding to 0.85 milligrams of elemental arsenic[1] per kilogram of body weight per day was established for glycerol arsenosugar, based on neurobehavioural effects observed in mice.
  • High consumers of certain seaweeds could be exposed to levels of glycerol arsenosugar corresponding to 0.71 micrograms of elemental arsenic[1] per kilogram of body weight per day.
  • Taking into account a default uncertainty factor and the incomplete database for glycerol arsenosugar, the CONTAM Panel considered that an MOE greater than or equal to 1000 would not raise a health concern.
  • Comparing the highest dietary exposure to glycerol arsenosugar with the RP for neurobehavioural effects resulted in an MOE greater than 1000, thus not raising a health concern.

Outcomes for other arsenosugars:

  • No risk characterisation could be conducted for arsenosugars other than glycerol arsenosugar, due to a lack of data.

Outcomes for arsenolipids:

  • No risk characterisation could be conducted for arsenolipids due to a lack of data.

General outcomes:

  • The CONTAM Panel concluded that it is likely that dietary exposures to arsenobetaine and glycerol arsenosugar do not raise a health concern.

What were the limitations/uncertainties?

  • As indicated above with respect to the various outcomes, there was a lack of both occurrence and toxicity data for complex organoarsenic species. For a detailed analysis of the uncertainties and how they were taken into account, please refer to section 3.5 of the scientific opinion.

What are the key recommendations?

Recommendations for the legislators:

  • If the EC finds it necessary, these results could inform risk management strategies, such as setting legally binding maximum levels for complex organoarsenic species in food.

Recommendations for the research community:

  • There is a need for occurrence data and an improved understanding of the toxicokinetics and toxicity data on complex organoarsenic species.

Glossary

Genotoxicity: When a substance can damage the DNA in cells.

Inorganic arsenic: Inorganic forms of arsenic are compounds that do not contain carbon-arsenic bonds. These include oxides, chlorides, sulfides, arsenites and arsenates, among others, and they occur naturally in soils and groundwater or as a result of human activity.

In vitro: A research method which involves testing cells or tissues extracted from living organisms.

Margin of exposure (MOE): A tool used in risk assessment to explore safety concerns arising from the presence of a potentially toxic substance in food or animal feed. It is the ratio of the reference point (the dose at which a low but measurable adverse effect is observed) to the level of exposure to the substance in a given population. A low MOE represents a greater risk. The minimum magnitude of the MOE needed for concluding that the exposure is of low health concern depends on the substance’s genotoxicity, carcinogenicity, and diverse sources of uncertainty.

Neurobehavioural effects: Conditions concerning the way the brain communicates with the nervous system, which can manifest as behavioural, emotional, physical or learning problems. 

No observed adverse effect level (NOAEL): The greatest concentration or amount of a substance at which no detectable adverse effects occur in an exposed population.

Organic arsenic: Organic forms of arsenic are compounds that contain carbon-arsenic bonds. These include methylated arsenic compounds, arsenobetaine, arsenolipids and arsenosugars, among others, and they are primarily found in seafood and marine environments.

Reference point (RP): The defined point of an experimental dose–response relationship denoting a critical effect, which is used to assess the potential risks of exposure to a given hazard. It is often used to establish a safe or acceptable level of exposure.

Toxicity: The potential of a substance to cause harm to a living organism.

Toxicokinetics: The study of the processes by which potentially toxic substances are handled in the body. This involves an understanding of the absorption, distribution, metabolism and excretion of such substances.

References

Licht O, Breuer F, Baskirov A, Blümlein K, Kellner R, Pallapies D, Partosch F, Pieczyk B, Schwonbeck S, Wiedemeier P and Zwintscher A, 2022. Extensive literature search on organic arsenic in food. EFSA Supporting Publications, 19(9):EN-7565. https://doi.org/10.2903/sp.efsa.2022.EN-7565 

Risk assessment of complex organoarsenic species in food.
DOI: https://doi.org/10.2903/j.efsa.2024.9112 

[1] In the context of quantifying the reference point and the exposure to complex organoarsenic compounds, this term is used to refer to the amount of arsenic expressed in its elemental form (not combined with other elements).