The Cardno ChemRisk View
Ochratoxin A (OTA) in U.S. Breakfast Cereals
Cardno ChemRisk presented an abstract at the 2017 Society of Toxicology Annual Meeting in Baltimore, Maryland titled, “Risk Assessment for the Consumption of Ochratoxin A (OTA) in Breakfast Cereals in the US”.
Ochratoxin A (OTA) is a naturally occurring mycotoxin and is a stable contaminant found in the production and storage of cereals and grains. OTA is of interest, as it has been shown to cause kidney tumors in mice and rats, and is classified as a Group 2B carcinogen by the International Agency for Research on Cancer (IARC). Additionally, Health Canada has derived a negligible cancer risk intake (NCRI) of 4 ng/kg bw/day, corresponding to a 1 in 100,000 risk level, based on a TD05 of 19.6 μg/kg bw/day and a safety factor of 5000. In the U.S., there is currently no health based guidance value for OTA.
In our analysis, we assessed the potential cancer risks associated with consumption of OTA in different grain-based cereals in the U.S. OTA intake was estimated using the mean and maximum estimates of U.S. cereal consumption (various age groups, as reported in the EPA 2011 Exposure Factor Handbook) and mean OTA levels in grain-based U.S. cereals (as calculated from published literature).
Our results illustrated that OTA doses associated with mean cereal consumption rates are below the NCRI “negligible cancer risk” dose. The OTA doses associated with maximum consumption rates approach the NCRI value for several cereal types and exceed the NCRI for conventional oat cereal. Therefore, we concluded that the risk of cancer in the U.S. from OTA exposure is not likely to be of concern based on mean estimates of U.S. cereal consumption and mean OTA levels in grain-based cereals. However, under conditions of high consumption of oat cereal the OTA intake exceeds the NCRI.