Paper drinking straws touted as eco-friendly alternatives to plastic may contain cancer-linked “forever chemicals,” a new study has found.
Scientists detected perfluorinated and polyfluorinated substances (PFAS) in the majority of straws they tested — with paper and bamboo-based straws ranking among the worst offenders, according to the study, published Thursday in Food Additives and Contaminants.
Known for their nonstick and waterproof properties, PFAS are common ingredients in a variety of household products, including certain cookware, food packaging, all-weather apparel and cosmetics.
There are thousands of types of PFAS, some of which have been linked to testicular cancer, thyroid disease, kidney cancer and other illnesses. These synthetic compounds are also notorious for their persistence in the human body and the environment.
“Straws made from plant-based materials, such as paper and bamboo, are often advertised as being more sustainable and eco-friendly than those made from plastic,” corresponding author Thimo Groffen, an environmental scientist at the University of Antwerp, said in a statement.
“However, the presence of PFAS in these straws means that’s not necessarily true,” Groffen added.
Building upon a 2021 study that identified PFAS in U.S. drinking straws, Groffen and his colleagues sought to determine whether the same was true in their home country, Belgium.
The authors found this question particularly interesting as a growing number of countries, including the U.K. and Belgium, have banned the sale of single-use plastic products, including straws.
For its part, the U.S. currently has no such bans, although several states have prohibited single-use plastic bags in stores.
To draw their conclusions, Groffen and his colleagues purchased 39 brands of drinking straws made from five materials: paper, bamboo, glass, stainless steel and plastic.
The scientists then conducted two rounds of testing for PFAS — determining that 29 brands, or 69 percent, contained these substances. They detected 18 types of PFAS.
Paper straws were most likely to contain PFAS, with the substances found in 18 of 20 brands, or 90 percent. Of the bamboo brands, four out of five — or 80 percent — had PFAS, according to the study.
Three out of the four plastic straw brands, or 75 percent, contained PFAS, compared to two out of five, or 40 percent, of glass brands. None of the five types of stainless-steel straws sampled contained PFAS, the scientists noted.
The most identified compound, PFOA, has been banned around the world since 2020.
The researchers also expressed concern about the presence of the substances TFA and TFMS, which they said are “ultra-short chain” PFAS that are highly water-soluble and could leach out of straws into drinks.
The authors noted, however, that they did not test whether the PFAS was actually leaching from the straws into liquids.
It is not yet known whether the PFAS was added to the straws during the production process for waterproofing purposes, or whether the presence of these substances is the result of contamination.
For example, plant-based materials could have been grown in polluted soil, or contaminated water could have been used in the manufacturing process, the authors explained.
Because the concentrations of PFAS were low in these products and while most people only use straws occasionally, the researchers acknowledged that these levels only pose a limited threat to human health.
Nonetheless, they stressed that PFAS can remain in the body for years and that concentrations can accumulate over time.
“Small amounts of PFAS, while not harmful in themselves, can add to the chemical load already present in the body,” Groffen said.
Their findings, he continued, also demonstrate that paper and bamboo straws are not necessarily biodegradable.
“We did not detect any PFAS in stainless-steel straws, so I would advise consumers to use this type of straw — or just avoid using straws at all,” Groffen added.