Written by By Linda Pan, CNN
An anti-pollution study released this week by oceanographers found levels of industrial chemicals in high quantities in tuna from at least three companies. Two of them — McDonald’s and Burger King — sent raw or frozen fish to the same supplier.
The Guardian says one “tuna expert” believes the chemicals could be caused by their curing or freezing process. All are on the U.S. Environmental Protection Agency’s list of toxic chemicals known to cause reproductive effects in humans, though it is unclear what effect they have on animals.
According to the study, “24 species tested from large chains with reported tuna supplies in the U.S., including Wendy’s, Subway, and the two McDonald’s chains,” had high levels of harmful chemicals.
McDonald’s and Burger King didn’t respond to requests for comment. But one of the study’s authors, marine ecologist Luke McKernan, wrote to CNN: “While we’re well aware of the many, many problems associated with industrial processes, the use of such chemicals in the food chain has been virtually left to industry to stop.”
He went on to say that in some cases the toxic chemicals had been given as ingredients to fish, including canned tuna.
We don’t know for sure what they are — most of them were in the “elegant” category of chemicals, he wrote — and the study simply points out that “once we see high levels of a certain chemical, we should assume it is safe to eat more of it.”
The study is based on a sample of nearly 100 samples — 51 had high levels of the toxin trihexazoline, for example. Dr. Ryan Joerger, a senior scientist at the National Center for Ecological Analysis and Synthesis, told the Guardian: “This is a toxin you could find in your yard or car tires or in the air, probably.”
It’s not the first study to show that fish found on supermarket shelves is about to cause a near panic. Scientists found that Asian carp — a type of carp normally found in freshwater — was making its way northward, unchecked. Researchers have been working with British politicians, businesses and scientists to fight the fish, which has the potential to threaten U.S. food chains.