Not just water, food, wine and underground aquifers. Trifluoroacetic acid, better known as TFA, was also detected in the blood of all 110 European people involved in a new study promoted by the Green group in the European Parliament on the initiative of the Green and Left Alliance MEP Cristina Guarda.
The data is significant above all for the concentrations detected: the median value was equal to 21.22 nanograms per milliliter, with levels between 4.67 and 58.35 ng/mL. According to PAN Europe, which released the results, these are some of the highest TFA values so far measured directly in human blood.
The study sample is limited and naturally does not allow us to establish how representative those concentrations are of the entire European population, but the fact that TFA was found in all the samples analyzed adds a new piece to a picture of environmental contamination that in recent years has become increasingly difficult to ignore.
What is TFA and why is it a concern
TFA, trifluoroacetic acid, belongs to the vast family of per- and polyfluoroalkyl substances, PFAS, and is one of the ultra-short chain fluorinated compounds. It can be released directly into the environment or form from the degradation of various substances containing fluorinated -CF3 groups, including some PFAS pesticides.
Its characteristic is persistence: once released into the environment, TFA is extremely difficult to degrade and is very mobile. It therefore has the ability to move easily between soil, surface water and groundwater, entering the food chain.
Unlike several long-chain PFAS, it does not tend to accumulate in human tissues in the same way. However, this does not mean that exposure is negligible: precisely because it is continuously released into the environment and moves easily in water, we can come into contact with it repeatedly through what we drink and eat.
PAN Europe also highlights that TFA has been classified as a reproductive toxicant and recalls studies which, at certain doses, have observed possible effects on development in the early stages of life, on the thyroid and on the immune system.
The study
The researchers analyzed the blood of 110 participants for both long-chain, short- and ultra-short-chain PFAS. TFA was detected in 100% of the samples and, according to the data reported, its concentrations were on average four to five times higher than those observed overall for the other long-chain PFAS analyzed.
Then there is an interesting detail: TFA levels in serum showed only a weak correlation with those of PFOA and little or no correlation with other long-chain PFAS. An element which, according to the authors, suggests that the sources of exposure to TFA may be at least partly different from those of other fluorinated compounds.
@PanEurope
The result is part of a literature that is still relatively scarce: direct measurements of TFA in human blood are in fact much less common than those dedicated to the better-known PFAS.
How much TFA was found in previous studies
However, some research conducted in recent years allows us to make a comparison. A study of 252 adults in China found TFA in 97% of samples, with a median concentration of 8.5 ng/mL. Another US study found it in 74% of 81 participants, while a study of 119 adults in North Carolina recorded a median of 17 ng/mL.
More recently, a study on the Norwegian EuroMix cohort identified TFA as the single most abundant PFAS among those analyzed. Among people not taking fluoxetine, a fluorinated drug also known by some of its brand names, the median concentration was 6.22 ng/mL. Among users of the drug it rose to 27.7 ng/mL.
This is important data because it shows how even some fluorinated medicines can contribute to exposure to TFA and reminds us of how complex it is to reconstruct all the sources of this substance.
PAN Europe especially points the finger at PFAS pesticides. According to the organisation, there are around 30 pesticide active substances belonging to the PFAS family on the European market, used in hundreds of products, and almost all of them can degrade to form TFA.
According to the data recalled by the organisation, the concentrations in food can be much higher than those present in water, making food a possible important source of exposure for the population.
A recent study on Austrian groundwater also observed a significant increase in TFA concentrations over four years. The levels were associated with some agricultural indicators, such as nitrate concentrations and pesticide use, while they did not show the same association with other PFAS.
The health limit
There is currently no specific safety threshold for TFA in the blood. However, EFSA has set an acceptable daily dose of 0.014 mg per kg of body weight, based on the effects observed on the thyroid. In the report, this dose is associated, with an indicative estimate, with a concentration in the blood of approximately 24 ng/mL: a value very close to the median of 21.22 ng/mL detected in the 110 participants. However, the comparison should be interpreted with caution, because it is not a clinical threshold and because in real life we are exposed to many PFAS at the same time.
For PAN Europe the problem is above all the persistence of TFA: by continuing to release it into the environment, the concentrations are destined to increase. This is why the organization is calling for a ban on PFAS pesticides that can generate it and for a broader European restriction on these substances.
In short, the study does not demonstrate that the levels detected cause health effects, but it shows how widespread exposure is. And it is clear that TFA was found in all samples analyzed.
