16 April 2026
Researchers underscore urgent need for evaluation health impacts

A new study shows that a specific type of silicone, the so-called methylsiloxanes, are widely present in the atmosphere across diverse environments. Also, concentrations appear to be much higher than expected. According to the researchers, this raises concerns about their potential, yet poorly understood, effects on human health and the climate. Methylsiloxanes are commonly used in industry, transportation, cosmetics and household products. The study was supervised by Utrecht University and the University of Groningen, and the results were published today in Atmospheric Chemistry and Physics.


Synthetic pollutants, such as PFAS and microplastics, are notoriously pervasive in the environment. One class of these synthetics, a water-repellent lubricant named methylsiloxanes, received little attention. Whenever it was detected in the atmosphere, researchers assumed it came from the evaporation of methylsiloxanes in personal care and industrial products. However, a few years ago, researchers found that ships and vehicles emit a substantial amount of a different variant of methylsiloxanes, consisting of large molecules that do not evaporate.

High concentrations
In this new study, researchers discovered that these large molecular methylsiloxanes are commonly present in the atmosphere, not only in areas close to traffic, but across diverse environments, including urban, coastal, rural, and forest sites.

“The findings also suggest that concentrations of methylsiloxane in the atmosphere are much higher than expected”, says Rupert Holzinger, associate professor at Utrecht University who co-supervised the study. In fact, large molecular methylsiloxanes appear to be one of the most concentrated synthetic compounds in the atmosphere, making up 2 to 4.3 percent of the total mass of organic aerosols. Atmospheric PFAS concentrations are typically more than three orders of magnitude lower than those observed for methylsiloxanes.

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