What is Arsenic?

Arsenic is a naturally occurring chemical element found throughout our environment and its living systems. Arsenic can enter groundwater through erosion and weathering of soils, minerals, and ores. Arsenic compounds are used in the manufacture of a variety of products and may enter our environment directly from industrial effluents and indirectly from atmospheric deposition.

Arsenic exists in different chemical forms, which can be classified into two groups: organic arsenic and inorganic arsenic.

Arsenic and Food

Arsenic can be found at very low levels (low parts per billion (ppb)) in many foods, including meat and poultry, milk and dairy products, bakery goods and cereals, vegetables, and fruits and fruit juices. The trace levels of arsenic in foods generally reflect normal accumulation from the environment.

Both organic and inorganic forms of arsenic can be found in food, although the relative proportions of each depend on the type of food. Arsenobetaine, an organic arsenic compound, is most commonly found in fish and shellfish. Inorganic arsenic is not usually found at high concentrations although rice and some types of seaweed can contain higher amounts of inorganic arsenic compared to other foods.

Health Effects of Exposure to Arsenic

The toxicity of arsenic depends on its chemical form. It is widely recognized that inorganic forms of arsenic are of greatest potential concern to human health as compared to organic forms. Long-term exposure (over many years or decades) to elevated levels of inorganic arsenic is known to contribute to the risk of certain human cancers and can affect the gastrointestinal tract, kidneys, liver, lungs and epidermis.

Short term exposure (over multiple days or weeks) to very high levels of inorganic arsenic can also cause various health effects including skin lesions, nausea, diarrhea, vomiting and numbness in hands and feet.

Although relatively limited, there is some evidence that children may metabolize arsenic differently than adults and that in-utero and childhood exposure to high levels of inorganic arsenic may affect fetal and childhood health and development and could be associated with increased susceptibility to cancer in adulthood.

Available toxicological information suggests that most organic arsenic compounds, such as arsenobetaine and arsenocholine, have very limited toxicity. However, there is increasing evidence supporting that monomethylarsonic acid and dimethylarsinic acid may be more toxic compared to other organic arsenic compounds. Health Canada will continue to review new research relating to arsenic toxicity, particularly its effects on children, as well as the toxicity of methylated organic arsenic compounds.

What is Health Canada Doing?

Health Canada continues to monitor the concentrations of various chemicals, including arsenic, in foods through its ongoing Total Diet Study surveys and also conducts targeted surveys of arsenic in specific foods. Additionally, the Canadian Food Inspection Agency carries out monitoring and surveillance work for arsenic in foods, including those commonly consumed by infants and children.

Health Canada will consider new information relating to the toxicity of arsenic and the occurrence of arsenic in foods. Relevant information will be used to update the overall dietary exposure assessment for arsenic and examine the relative contribution of different types of foods in the Canadian diet to exposure. Health Canada will also continue to evaluate the potential human health risks associated with dietary arsenic exposure.

The Food Directorate is updating the maximum levels (MLs) for arsenic in foods that are found in Part 2 of the List of Contaminants and Other Adulterating Substances in Food, which is incorporated by reference into Division 15 of the Food and Drug Regulations. Additionally, Health Canada’s Food Directorate is an active participant in the Codex Committee on Contaminants in Food (CCCF), which develops international food safety standards, including MLs for arsenic in certain foods. Maximum levels established by the CCCF and adopted by the Codex Alimentarius Commission (CAC) are generally considered for their applicability in Canada, on an as-needed basis.

What Can You Do?

Health Canada continues to recommend that Canadians follow Canada's food guide and eat a variety of healthy foods each day.

Additional Resources

To obtain an electronic copy of the January 2016 - Scientific Assessment in Support of a Lower Tolerance for Arsenic in Apple Juice, please contact our publications office or send an e-mail to with the subject heading "hpfb BCS arsenic scientific evaluation 2016-eng"

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