by Anna Fregonara
Perfluoroalkyl substances are found in frying pans, food containers, tap water and waterproof fabrics. According to a new study, they spread in the environment. Here’s how to limit your exposure
We all come into contact with it every day: when we dress in waterproof clothing, when we cook with non-stick pans, when we clean our teeth with dental floss, when we buy ready-made food or lubricate the bicycle chain.
PROPERTIES
Pfas, an English acronym for PerFluorinated Alkylated Substances, i.e. perfluoroalkyl substances (or perfluoroacrylic acids) widely used by industry due to their properties, are found in many everyday objects. Success depends precisely on their characteristic of behaving in such a way as to be water and oil repellent, but at the same time to be breathable and resistant to high temperatures. The action of the Pfas is the result of a chemical reaction of carbon and fluorine, explains Emilio Benfenati, head of the Environment and Health Department of the Mario Negri Research Institute in Milan.
The new studio
New research, however, would show that they are not so safe for our health. A group of researchers in Environmental Science & Technology Letters studied the presence of these compounds in 42 Canadian food packaging used for fast food, from sandwich wraps to salad containers. When the researchers reanalysed the same samples stored in a sealed bag in the dark at room temperature two years later, they noticed that the composition of Pfas had changed: their total concentration had decreased by as much as 85%, which should not have been possible. In fact, the new Pfas, called polymeric, were born as alternatives to the more traditional long-chain ones and the logic was that they were safer because they were more stable and too heavy to escape from the materials in which they are present. Instead it appears that they break down into smaller potentially toxic molecules and that spread in the environment, where they can remain for centuries without biodegrading, and in food.
The risks
The main expository route is the oral one, continues the expert, we therefore absorb them from what we eat and drink. Don’t be alarmed, however, because no single product can expose you to dangerous levels of Pfas in a single use. However, since they are common and can build up in the body over time, you can see how to reduce your exposure. First through regulation. The European Food Safety Authority (EFSA) gave its opinion by evaluating the results of the scientific studies available, both epidemiological and on animals (the latter in the case of Pfas are not always directly transferable to humans), and found an increase in cholesterol, while other reports showed alterations in the liver and thyroid, the immune and reproductive systems, development of some types of neoplasms.
Where are the foods?
In 2020, EFSA indicated a new safety threshold for 4 of the main PFASs that accumulate in the body. A tolerable weekly dose of 4.4 nanograms per kilo of body weight per week, explains Stefano Polesello, researcher at IRSA (Water Research Institute)-Cnr of Brugherio (Milan). The only way to defend yourself would be not to drink or eat. Pfas are widespread in all waters, even in rains in remote areas, but we continue to drink tap water because it is generally controlled. The foods that accumulate the most Pfas are eggs and liver. It doesn’t mean not eating eggs anymore, but limiting the consumption of those from impacted areas. Vegetables and fruit can absorb Pfas from the ground, but they are short chains that our body does not accumulate, even if we cannot exclude a priori that they have no effect, concludes Polesello.
Little tips
Instead, the small precautions that can be taken are, for example, changing the damaged Teflon pan and replacing it with a new one or one made of cast iron, stainless steel or ceramic, limiting the use of stain-resistant and water-resistant fabrics or choosing those that claim to be Pfas-free. The point on which I would focus more, however, is to reduce the frequency with which we eat from paper, cardboard and vegetable fiber packaging. These containers can have Pfas and thousands of other substances, such as phthalates or some plasticizers, which can be released into food. For this reason, it is better to choose fresh foods as much as possible so that we will also have many nutritional advantages. Finally, from the point of view of research, many studies will be needed before reaching a definitive conclusion on Pfas, developed for the first time in the 1940s and belonging to a large group of over 4,000 substances that vary in their chemical composition. For this reason, the main aspect is to identify priorities. Perhaps we focus on the fact that, cooking an omelette in Teflon which perhaps contains toxic substances, we perhaps absorb particles, but we lose sight, for example, that if we eat a toasted steak or pizza we absorb acrylamide which is certainly toxic, concludes Benfenati.
July 23, 2023 (change July 23, 2023 | 07:53)
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