Arsenic Speciation in Rice and Pear Products
The Food Safety Action Plan (FSAP) aims to modernize and enhance Canada's food safety system. The FSAP unites multiple partners in ensuring safe foods for Canadians.
Arsenic is a naturally occurring element found in trace amounts in rock, soil, water and air. Primary routes of human exposure to arsenic are through drinking water and food. The arsenic in food and water are generally considered to be from normal accumulation from the environment. Arsenic can exist in both organic (elemental arsenic combined with carbon) and inorganic forms (elemental arsenic coupled with oxygen, chlorine, sulphur or other elements other than carbon) in food, with the inorganic forms being the more toxic form. The ratio of arsenic species (organic and inorganic) can vary widely depending on the source of contamination and the commodities in which it is present. Inorganic arsenic is generally found at very low levels in foods, and is the predominant species in drinking water and vegetables (including rice), whereas organic forms are generally detected at higher levels and are the predominant species found in aquatic organisms (including fish and seafood). Chronic exposure to arsenic may lead to a variety of detrimental health effects in humans, most notably cancer.
The main objectives of this survey were:
- To provide baseline surveillance data for total arsenic levels in rice and pear products.
- To examine the proportions of inorganic arsenic in rice in pear products with a new analytical method.
A total of 213 samples were collected (108 pear products and 105 rice products). Both the rice and the pear products originated from domestic and imported origins. Samples were tested "as sold" to determine the total arsenic content. Those samples found to contain measurable levels of arsenic were further tested to determine the levels of various organic and inorganic species present.
All rice samples analyzed contained detectable levels of total arsenic. Brown rice contained the highest average levels of total arsenic at 0.24 ppm, followed by white rice at 0.14 ppm, rice drinks at 0.02 ppm and sake (a rice based alcoholic beverage) at 0.01 ppm. Arsenic speciation results indicate that the majority of the arsenic species present in white and brown rice samples tested are inorganic in nature, and that rice drinks contain a higher proportion of organic species. On average, inorganic arsenic species comprised 70-80% of all arsenic species detected in white and brown rice. In rice drinks and sake, inorganic arsenic accounted for an average of approximately 65% and 48% of all arsenic species detected, respectively. There are currently no established maximum levels for total arsenic or specific arsenic species in rice commodities. The levels of arsenic detected in the rice commodities tested herein would not be expected to pose a human health risk to the Canadian public.
With the exception of three products, all pear samples analyzed contained detectable levels of total arsenic. Pear snacks contained the highest levels of total arsenic with an average total arsenic concentration of 0.036 ppm, followed by pear juice at 0.007 ppm and pear nectar and baby food, which both had 0.003 ppm. Speciation results indicated that the pear juice contained a lower proportion of inorganic arsenic species, with approximately 20% of all arsenic species detected being inorganic in nature. Pear snacks, pear nectar and pear baby food had slightly higher proportions of inorganic arsenic detected, with about 35-55% of the total arsenic species being inorganic in nature. There is a maximum tolerance in Canada for arsenic in fruit juices, fruit nectar, and ready-to-serve beverages of 0.1 ppm. This would include pear juices and nectars, which were analyzed in this survey. All juice samples analyzed were well below this maximum tolerance. Levels of arsenic detected in other pear commodities would not be expected to pose an unacceptable human health risk to the Canadian consumer.
The complete text of this report is available upon request.
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