New Study Reveals Low Levels of Cyclic Volatile Methyl Siloxanes in Remote Arctic Environments

A recent study has provided strong evidence that Cyclic volatile methyl siloxanes (cVMS) levels in remote Arctic environments are low, and that atmospheric deposition via snow and snowmelt is not a major pathway for cVMS contamination.

Background
Cyclic volatile methyl siloxanes (cVMS) are highly volatile compounds that predominantly emit into the atmosphere, where they degrade into silanols via reactions with hydroxyl (OH) radicals. Their potential for long-range atmospheric transport has been well-documented, with notable wintertime concentrations observed at the Zeppelin Observatory in Svalbard. For cVMS to pose an environmental risk in remote ecosystems, atmospheric deposition onto terrestrial or aquatic surfaces is required. However, empirical studies generally report low cVMS levels in remote environments, and modeling assessments suggest minimal deposition potential due to the compounds’ high volatility.

Contrarily, a study by Sanchís et al. (2015b) detected elevated cVMS concentrations in Antarctic environmental compartments, proposing snow scavenging as a potential deposition mechanism. Given the lack of supporting air and snow measurements in that study, further investigation was required.

The Study
This study aimed to evaluate the potential for cVMS deposition in Arctic terrestrial and aquatic environments, focusing on samples collected from the Zeppelin Observatory region and an even more remote location, Diesetvatna, which is expected to be free from local cVMS sources.

Fieldwork was conducted in Svalbard at three sites:

• Zeppelin Observatory: A remote location used for ongoing air and environmental monitoring.
• Ny-Ålesund Settlement: A location with human inhabitants, examined as a potential local source of cVMS.
• Diesetvatna: A remote location expected to be free from local cVMS sources.

Samples were collected from soil, vegetation, sediment, fish, and air, with strict field and laboratory quality control.

Conclusions
The study concludes that cVMS levels in remote Arctic environments are low and that atmospheric deposition via snow and snowmelt is not a major pathway for cVMS contamination. While Ny-Ålesund has slightly higher air concentrations, this is expected with it being a potential local source, and the impact of these air concentrations on local soil and aquatic environments appears negligible.

This study provides valuable insights into the behavior of cVMS in remote Arctic environments and underscores the importance of continued monitoring and research in these regions.