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There’s a new acid in our rain — should we be worried?

Scientists and regulators are divided over the threat posed by rising levels of a chemical called TFA.
By
  1. XiaoZhi Lim

    1. XiaoZhi Lim is a freelance writer in Singapore.

Close-up of rain falling down and raindrops splashing.

Rainwater contains rising levels of a human-made chemical called trifluoroacetic acid (TFA). Credit: Ali Majdfar/Getty

Whenever rain or snow falls from the skies, a human-made chemical called trifluoroacetic acid (TFA) falls with it. Across the world, this chemical has shown up in lakes and rivers; bottled water and beer; cereal crops and animal livers; and even in human blood and urine1. And wherever researchers measure changes in TFA levels, they find that concentrations are rising.

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Nature 643, 894-897 (2025)

doi: https://doi.org/10.1038/d41586-025-02259-6

References

  1. Arp, H. P. H., Gredelj, A., Glüge, J., Scheringer, M. & Cousins, I. T. Environ. Sci. Technol. 58, 19925–19935 (2024).

    Article  PubMed  Google Scholar 

  2. Freeling, F. et al. Environ. Sci. Technol. Lett. 9, 400–405 (2022).

    Article  Google Scholar 

  3. Freeling, F. & Käberich, M. Long-term Trends for Trifluoroacetic Acid in Terrestrial Environmental Samples [In German] (Federal Environment Agency, 2023).

    Google Scholar 

  4. Pickard, H. M. et al. Geophys. Res. Lett. 47, e2020GL087535 (2020).

    Article  Google Scholar 

  5. Albers, C. N. & Sültenfuss, J. Environ. Sci. Technol. Lett. 11, 1090–1095 (2024).

    Article  Google Scholar 

  6. Scheurer, M. et al. Water Res. 126, 460–471 (2017).

    Article  PubMed  Google Scholar 

  7. Boutonnet, J. C. et al. Hum. Ecol. Risk Assess. 5, 59–124 (1999).

    Article  Google Scholar 

  8. Frank, H., Christoph, E. H., Holm-Hansen, O. & Bullister, J. L. Environ. Sci. Technol. 36, 12–15 (2002).

    Article  PubMed  Google Scholar 

  9. Scott, B. F. et al. Environ. Sci. Technol. 39, 6555–6560 (2005).

    Article  PubMed  Google Scholar 

  10. Joudan, S., De Silva, A. O. & Young, C. J. Environ. Sci. Process. Impacts 23, 1641–1649 (2021).

    Article  PubMed  Google Scholar 

  11. Freeling, F. & Mangels, A. Analysis of Current Seawater Samples for Trifluoroacetic Acid [In German] (Federal Environment Agency, 2024).

    Google Scholar 

  12. Tang, W. et al. Preprint at bioRxiv https://doi.org/10.1101/2025.03.06.641713 (2025).

  13. Cornish, J. et al. Am. J. Physiol. 277, E779–E783 (1999).

    PubMed  Google Scholar 

  14. Xu, B., Alizray, R., Lammel, D. R., Riedel, S. & Rillig, M. C. Eur. J. Soil Sci. 73, e13266 (2022).

    Article  Google Scholar 

Download references

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