Mapping PFAS Contamination in Packaged Foods

When grabbing a sweet, sticky bun from the grocery store for breakfast, one might rejoice in the fact that it cleanly slides out of the wrapper and onto a plate. While consumers may not think twice about why it is not sticking, researchers are trying to shed light on how this convenient packaging could potentially expose humans to toxic chemicals called PFAS.

Per- and polyfluorinated alkyl substances (PFAS) are a class of man-made chemicals lauded for their nonstick and oil-repellent characteristics. While useful in the food industry, there is evidence that exposure to these persistent chemicals may lead to adverse outcomes in human health.

Supported by the Agriculture and Food Research Initiative (AFRI) of the USDA National Institute of Food and Agriculture (NIFA), the University of Pittsburgh’s Carla Ng will lead a project that aims to be the first systematic study of the kinds and amount of PFAS that are present in imported and domestic food packaging. She and her collaborators from Indiana University and the USDA – Agricultural Research Service (ARS) will create a database that they hope will help guide better policy around the use of PFAS in the food industry.

“Humans are exposed to PFAS in a variety of ways, but depending on where you live, food is likely your major source,” said Ng, assistant professor of civil and environmental engineering at Pitt’s Swanson School of Engineering. “There are many different types of PFAS, and we don’t have enough information on where they are used, in what quantities, and whether they’re toxic, so we will use this award to study those details.”

According to the FDA, there are nearly 5,000 different types of PFAS. To add to the complexity of this issue, other countries have adopted different approaches to regulating PFAS and its many varieties.

For example, PFOA and PFOS have been phased out in the United States, but they are still widely produced in China. While they do not send these specific chemicals to the U.S., there may be residual chemicals that are transferred during production.

“Because of these uncertainties, we want to understand how all the different origins of packaging will impact which PFAS actually wind up in the consumer product,” said Ng.

The research team will inspect national supermarket chains and local international food stores to get an idea of the type and geographic origin of food packaging. They will then collect a representative sample of products and analyze the packaging for the presence of PFAS.

“We will use extraction and migration assays to evaluate the packaging,” explained Ng. “Extraction would represent an extreme case where we use harsh chemicals to gather a sample. Alternatively, the migration assays use simulants which represent different types of food – such as fatty, acidic, or salty. It will show, under normal conditions, how much PFAS transferred from packaging to food.”

ARS researcher Yelena Sapozhnikova will contribute to this work by identifying PFAS chemicals migrating from food packaging materials with non-targeted, high-resolution mass spectrometry. Sapozhnikova's interest in this research is a direct result from her previous work on identification of chemicals from food contact materials.

Once the PFAS structures are identified, they will go to Amina Salamova, associate scientist at IU’s O’Neill School of Public and Environmental Affairs, whose team will quantify how much of each structure is in the sample.

“We’re excited to conduct research that has such big implications for consumer safety,” Salamova said. “This research will help us understand a lot more about a group of chemicals that are widely used but not well understood.”

From there, the analyzed extracts and simulants will go to Pitt to be tested for toxicity. Ng’s lab specializes in molecular modeling that can initially screen the samples before evaluating them in zebrafish for further validation.

The results of the project will reveal whether the chemicals present in the packaging are toxic and if the concentration is high enough to contaminate your food. The researchers hope that this work will inform regulators, provide a risk assessment tool, and potentially reveal hot spots for PFAS exposure in our food system.

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