While enjoying fast food, many people feel some pangs of guilt at the calories and salt they are consuming. Today researchers are pointing to yet another possible cause for concern.

In a paper published in Environmental Science & Technology Letters, scientists found fluorinated chemicals in about a third of take-out food packaging samples tested. Previous research has shown these chemicals can migrate from packaging into the food which people eat.

Fluorinated chemicals are used to give water-repellant, stain-resistant, and non-stick properties to consumer products such as furniture, carpets, outdoor gear, clothing, cosmetics, cookware, and even food packaging materials. The most studied of these substances has been linked to kidney and testicular cancer, elevated cholesterol, decreased fertility, thyroid problems and changes in hormone functioning in adults as well as adverse developmental effects and decreased immune response in children.

In this study, the scientists from Silent Spring Institute, Notre Dame, Environmental Working Group, the Environmental Protection Agency and the Green Science Policy Institute collected and analyzed fast food packaging for this family of chemicals. In 400 samples of take-out packaging from fast food restaurants across the U.S., they found that 46% of food contact papers and 20% of paperboard contained fluorinated chemicals.

"We should question putting any fluorinated materials into contact with food," said Dr. Arlene Blum of UC Berkeley and the Green Science Policy Institute, an author of the study. "Given the potential for harm, we must ask if the convenience of water and grease resistance is worth risking our health."

"I was very surprised to find these chemicals in food contact materials from so many of the samples we tested," said Graham Peaslee, a physicist at the University of Notre Dame who developed the innovative new technique called PIGE that rapidly screens materials for the presence of fluorinated chemicals. "These chemicals are persistent and some bioaccumulate in the body, and there are safer non-fluorinated alternatives available."

Another recent study by some of the same authors found fluorinated chemicals in the drinking water of an estimated six million Americans. These substances have been found in the blood of almost everyone tested. The carbon fluorine bond is so strong that these chemicals don't break down, and can remain in the environment, causing harm for millions of years. A variety of technologies are being used to remove fluorinated chemicals from drinking water­at a very high cost.

"We don't want to drink these chemicals in our water nor do we want to eat them in our food," says lead author Laurel Schaider of Silent Spring Institute "The use of fluorinated chemicals in fast food packaging is of great concern since millions of Americans, including children, eat fast food every day."

"At the Danish Coop (Denmark's largest retailer), due to concerns about health, these chemicals were phased out from food packaging and textiles in 2015," according to Philippe Grandjean, a Danish-born professor at the Harvard T.H. Chan School of Public Health. "And it is time for the U.S. to consider following the Danish lead."

"Although several fluorinated chemicals found to be harmful are no longer used, dozens of related 'chemical cousins' are replacing them," explains Tom Bruton of UC Berkeley and the Green Science Policy Institute. "Like the older substances, these new fluorinated compounds do not break down in the environment and may be similarly toxic."

Some good news is that a number of leading retail brands including Ikea, Crate and Barrel, and Levi Strauss are eliminating all highly-fluorinated chemicals from their products. The food packaging industry should follow their lead.

Meanwhile, to reduce exposure, consumers can avoid food in contact with greaseproof packaging, such as microwave popcorn, some pizza boxes, take-out containers and wraps around fast food.

"We can stop using fluorinated chemicals where they are not necessary, such as in food packaging, and all be healthier," according to Blum.

Article: Fluorinated Compounds in U.S. Fast Food Packaging, Laurel A. Schaider, Simona A. Balan, Arlene Blum, David Q. Andrews, Mark J. Strynar, Margaret E. Dickinson, David M. Lunderberg, Johnsie R. Lang, and Graham F. Peaslee, Environmental Science & Technology Letters, doi: 10.1021/acs.estlett.6b00435, published 1 February 2017.