Arsenic, once known as the “king of poisons,” is a naturally occurring element found worldwide at low levels in water, food, air, and soil. Human exposure to arsenic can occur through ingestion of unregulated drinking water and certain agricultural commodities, particularly rice. In recent years, several studies by consumer advocacy groups have highlighted the presence of this toxic metal in a variety of food products.
On August 5, the Food and Drug Administration (FDA) issued a long-awaited guidance establishing an action level of 100 parts per billion (ppb) for inorganic arsenic in infant rice cereal. While the FDA action level is a good start, the United States still lags behind other nations in terms of setting limits for heavy metals in food. Here are five facts to consider in regard to arsenic and the food supply.
1. Arsenic is a Public Health Risk
Arsenic is ubiquitous in the natural environment in either organic or inorganic forms. Inorganic arsenic is the most toxic form of this heavy metal, and long-term exposure to inorganic arsenic has been linked to a wide range of serious health conditions, including various cancers, cardiovascular disease, diabetes, and blood diseases.
In 2016, the FDA completed a risk assessment regarding the human health effects associated with arsenic from rice, and the agency released a draft guidance proposing an action level for arsenic in infant rice cereal. The FDA risk assessment concluded the lifetime risk of cancer from arsenic would be diminished by reducing exposure to rice grain and rice products. According to the 2016 report, the elimination of rice grain and rice products from the diet during infancy (< 1year) and childhood (0 – 6 years) would potentially reduce the lifetime risk of cancer by approximately 6% and 23%, respectively.
In 2001, the federal limit for arsenic in drinking water was reduced from 50 ppb to 10 ppb in response to a 1999 report by the National Research Council that suggested the 50 ppb level presented a 1-in-100 risk of cancer.
2. The FDA is Monitoring Arsenic Levels in Food
Arsenic can be detected in many agricultural commodities exposed to soil, pesticides and surface water. The latest FDA Total Diet Study (2006-2013) reported some of the highest levels of total arsenic were found in fish, rice grain and rice products. Overall, the FDA has determined that rice grain and rice products represent the most significant dietary sources for inorganic arsenic.
The arsenic level in rice can be influenced by several factors, including the geographic source of rice, growing conditions, variety of rice, and rice milling practices. The FDA has focused on arsenic levels in infant rice cereal since the product represents a large proportion of the simple diet of infants and toddlers.
The FDA has conducted several surveys of arsenic in white and brown rice cereals. This year, the agency released the latest analytical results for inorganic arsenic in infant rice cereal, which reported a range of 22-142 ppb inorganic arsenic from 149 samples, and concluded 76% of the samples tested in 2018 met the 100 ppb action level. In 2016, the FDA reported an average level of 103 ppb inorganic arsenic after testing 76 samples of infant/toddler rice cereal. In recent years, a downward trend in arsenic in infant rice cereal has been attributed to manufacturers employing effective Good Manufacturing Practices (GMPs), including acquiring rice with lower levels of inorganic arsenic.
3. Consumers are Concerned about Heavy Metals
The United States has been slow to establish limits for heavy metals in food, but advocacy groups are urging the FDA to establish additional limits for arsenic and other heavy metals. The FDA action level for infant rice cereal is the first federal regulatory limit for arsenic in food. In 2013, the FDA introduced a 10 ppb action level for inorganic arsenic in apple juice following an independent study of elevated arsenic levels in the juice commonly consumed by children. Consumer Reports supports the 100 ppb arsenic limit for infant rice cereal but has urged the FDA to set additional limits for arsenic in rice products as well as limits for other heavy metals in baby food. The Consumer Reports studies of arsenic in rice products and juice generated significant media attention.
4. Arsenic Limits for Rice Exist in Canada, EU
Regulations for inorganic arsenic in foods are evolving worldwide, but the establishment of limits for arsenic in foods has been challenged due to limited data on its dietary impact. Despite these limitations, arsenic in rice is a global concern.
The Codex Alimentarius set a standard for inorganic arsenic in white rice (200 ppb) and brown rice (350 ppb), and published guidance in 2017 to support the mitigation of arsenic contamination in rice.
The European Commission issued regulatory limits for inorganic arsenic in rice-based foods. In 2015, the Commission regulation set limits for arsenic in white rice (200 ppb), brown rice (250 ppb), and rice intended for food in infants and young children (100 ppb).
In June, Health Canada announced new limits for inorganic arsenic of 200 parts per billion (ppb) in polished (white) rice, and 350 ppb in husked (brown) rice. The new maximum levels for inorganic arsenic in rice apply to rice-containing products.
5. Mérieux NutriSciences Testing & The FDA Method
Mérieux NutriSciences in North America is able to determine total arsenic in food and food ingredients using the conventional method of acid digestion followed by ICPMS. We are also able to determine the form of arsenic (inorganic vs. organic) using the FDA method 4.11 which involves a soft extraction so as not to alter the form of the arsenic, followed by separation by HPLC and detection and quantitation by ICPMS to levels far below any regulated limits in the world. We originally set this method up at the request of the FDA, as the only commercial lab alongside FDA regional labs, to generate data for the original risk assessment that the FDA performed on rice and a wide variety of rice products including baked goods, cereals, and rice-based beverages (including beers). Arsenic data from the Mérieux NutriSciences Burnaby facility was pooled with the data from FDA labs after passing stringent Quality standards to make this study possible. Since then Mérieux NutriSciences has expanded the scope of this method to include most types of foods, beverages, ingredients, and dietary supplements.