Siloxane Pollution Crisis: Shocking Levels of Methylsiloxanes in Air-Linked to Car Emissions-Exceed PFAS & Microplastics Exposure

A Hidden Pollutant in Our Air: Scientists Warn of Widespread Silicone Contamination

By Dr. Helena Fischer, Editor, Health | May 13, 2026

An overlooked class of synthetic compounds—methylsiloxanes—is now confirmed to be pervasive in the global atmosphere, according to new research published in Atmospheric Chemistry and Physics. These silicone-based pollutants, widely used in everything from cosmetics to industrial lubricants, are accumulating at concentrations far higher than previously recognized, raising urgent questions about their potential impact on human health and the environment.

The study, led by scientists at Utrecht University and the University of Groningen, reveals that methylsiloxanes—particularly larger, more stable molecules—are not just confined to urban centers but are detected in coastal, rural, and forested regions worldwide. What’s more alarming: more than half of these compounds appear to originate from traffic emissions, likely from engine lubricants that survive combustion and disperse into the air.

Why it matters: While pollutants like PFAS (“forever chemicals”) and microplastics have dominated environmental discussions, methylsiloxanes may now represent an equally insidious—and understudied—threat. Their persistence in the atmosphere suggests they could play a significant, yet poorly understood, role in climate processes and human exposure.

What Are Methylsiloxanes, and Where Are They Coming From?

Methylsiloxanes are a class of silicon-based compounds characterized by their Si–O–Si (siloxane) bonds, which give them unique properties: stability, flexibility, and water resistance. These traits make them indispensable in consumer products like shampoos, moisturizers, and waterproof fabrics, as well as in industrial applications such as engine lubricants and ship coatings.

Until recently, scientists assumed methylsiloxanes entered the atmosphere primarily through evaporation from personal care products. However, the new research published in Atmospheric Chemistry and Physics challenges this assumption. The team found that larger, more complex methylsiloxane molecules—those used in industrial lubricants—do not evaporate easily. Instead, they are released directly into the air through combustion processes, particularly from vehicles and maritime traffic.

Key findings from the study:

• Methylsiloxanes are detected at unexpectedly high levels across diverse environments, including remote forests and coastal areas.
• More than half of the large molecular methylsiloxanes in the atmosphere are linked to traffic emissions, likely from engine oil additives.
• Concentrations are significantly higher than previously estimated, suggesting widespread and chronic exposure.

Unknown Risks: What Do We Know So Far?

While methylsiloxanes have been studied in controlled lab settings, their long-term effects on human health and ecosystems remain largely uncharted territory. Unlike PFAS, which have been linked to cancer and immune disorders, or microplastics, which accumulate in marine life, methylsiloxanes lack comprehensive toxicity profiles.

However, preliminary research suggests potential concerns:

• Respiratory exposure: Given their ubiquity in the atmosphere, humans may inhale methylsiloxanes daily, though the health implications are not yet clear.
• Environmental persistence: Their stability means they may accumulate in soil and water over time, potentially disrupting microbial communities.
• Climate interactions: Like other airborne pollutants, methylsiloxanes could influence cloud formation and atmospheric chemistry, though their exact role is unknown.

Note: The study authors emphasize that further research is needed to assess the full scope of these risks. “We’re dealing with a pollutant that has been hiding in plain sight,” said one of the lead researchers. “Its widespread presence demands immediate attention from policymakers and the scientific community.”

How Do Methylsiloxanes Compare to PFAS and Microplastics?

What’s Next for Methylsiloxane Research and Regulation?

The discovery of methylsiloxanes as a global atmospheric pollutant has already sparked calls for action. In the short term, researchers are prioritizing:

• Toxicity studies: Lab and epidemiological research to determine potential health effects, particularly from long-term inhalation.
• Source tracking: Identifying specific industrial and consumer products contributing to emissions.
• Policy discussions: Advocating for regulatory frameworks similar to those for PFAS, given their persistence and ubiquity.

Preliminary discussions are underway among environmental agencies in the European Union and the U.S., though no formal regulations have been proposed. The European Environment Agency has acknowledged the findings as a “wake-up call” for monitoring programs.

What Can You Do?

While individual actions may have limited impact on a global scale, awareness and advocacy can drive change:

• Stay informed: Follow updates from Atmospheric Chemistry and Physics and environmental health organizations.
• Support research: Donate to or volunteer with groups studying emerging pollutants, such as the Environmental Working Group.
• Advocate for transparency: Push for corporate disclosure of methylsiloxane use in products, particularly in lubricants and personal care items.
• Reduce exposure: While evidence is limited, minimizing use of silicone-heavy products (e.g., certain cosmetics, waterproof fabrics) may lower personal risk.