- Food packaging, serving, and processing materials contain 14,402 known chemicals that people might consume, but the full extent of human exposure was not clear.
- Researchers found evidence for 3,601 of these chemicals in humans from a survey of biomedical databases. More than 100 such chemicals are highly hazardous, or their danger is unknown.
- Policymakers should restrict the food manufacturing industry from using these hazardous materials in items that contact food, the authors recommend.
At the end of a long day, you might sit down with friends or family to eat a bowl of hot noodle soup. A savory scent fills the air as you bring the broth to your lips. Whether that meal is homemade udon or canned chicken noodle soup, you will also unwittingly swallow chemicals that leached into the ingredients from everything they touched on their way to your table.
Food processing equipment, storage containers, packaging, and serving bowls all contain chemicals that can bleed into your food in tiny amounts. When you eat your soup, every noodle, vegetable, and protein picked up these “food contact chemicals” along the way. Researchers knew people ingested chemicals like bisphenol A (BPA) and phthalates with their food, but the full scope of this exposure was unclear.
To create such a catalogue, a team of public health specialists based in Switzerland compiled the results of three databases of molecules found in the human body, five biomonitoring programs, and hundreds of studies.
They found that among the 14,402 known food contact chemicals, 3,601 – more than 25 percent – are present in human blood, urine, hair, umbilical cords, placentas, and breast milk. Eighty of those chemicals cause cancer, decrease fertility, cause birth defects, or are toxic to humans. An additional 59 do not yet have safety information, according to a recent study published in the Journal of Exposure Science & Environmental Epidemiology.
The team only expected to find signs of the few hundred food contact chemicals screened in biomonitoring programs like the U.S. National Health and Nutrition Examination Survey. But when they expanded their search to other databases and scientific studies, they found thousands.
“It surprised us that we found so many more chemicals in these big databases,” said lead author Birgit Geueke, senior scientist at the Food Packaging Forum Foundation in Zurich, Switzerland.
Many plastics use synthetic antioxidants, but their presence in human exposure studies is rare because these compounds degrade easily. “I found that really surprising because it’s such a widely used chemical group,” said Geueke.
Oligomers, side products of plastic production, also are difficult to trace in humans because they vary in length. “There should be some analytical methods developed that easily allow the quantification [of oligomers], or at least their detection and migration,” Geueke added.
The team created an online database called FCChumon where anyone can look through the entire catalogue of chemicals. Users can sort by several categories, including packaging material type like plastic or metals. While open to the public, this database is designed for scientists to identify lesser-known food contact chemicals to study and for policymakers to support restrictions on harmful chemicals.
To reduce exposure, Geueke advises consumers to choose ingredients that come with less packaging, and to transfer food from plastic containers to glass or metal ones before heating it.
However, Geueke noted, “You cannot be made responsible for the chemical exposure coming from your food.” Instead, policymakers must create new regulations to force food manufacturers to change out the harmful materials that contact food for safe alternatives, her team concluded.
Almost all data used in this study came from people living in North America and Europe. Differences in environmental chemical exposure and food packaging practices may alter which chemicals show up in people living in other places, according to Geueke.
“This is the first step, and it’s a very important step,” said Kurunthachalam Kannan, deputy director of the Division of Environmental Health Sciences at the University at Albany, State University of New York, who was not involved in the study.
Kannan emphasized that scientists must improve analytical methods to quantify the amount of each food contact chemical in humans, as the authors also urged. “Then we can make a very strong justification for the regulatory agencies,” he said.
Citation: Geueke, B., Parkinson, L.V., Groh, K.J. et al. Evidence for widespread human exposure to food contact chemicals. Journal of Exposure Science & Environmental Epidemiology (2024). doi: 10.1038/s41370-024-00718-2
Rita Aksenfeld (ritaaksenfeld.com) is a graduate student in the Science Communication Program at the University of California, Santa Cruz. Other Mongabay stories produced by UCSC students can be found here.