Your Home's Natural Gas May Contain 73 Times More Benzene Than North American Supply

A groundbreaking study has revealed that homes across the United Kingdom, Netherlands, and Italy are being exposed to a potent carcinogen through their natural gas supply, with benzene levels reaching concentrations up to 73 times higher than what's typically found in North American gas. Researchers from PSE Healthy Energy and Stanford University tested 72 domestic gas samples and found benzene, a chemical with no safe exposure level according to the World Health Organization (WHO), in every single one.

Why Is Benzene in Your Gas Supply Such a Concern?

Benzene is a naturally occurring substance found in oil and gas fields that poses serious long-term health risks. The WHO classifies it as having no safe exposure level, and it's linked to leukemia and other severe health conditions. What makes this discovery particularly alarming is the sheer concentration differences between regions. Gas samples from London contained 64 times more benzene than typical North American gas, while Amsterdam's samples showed 73 times higher levels. The Netherlands overall had 66.5 times more benzene, and the United Kingdom averaged 37 times higher concentrations.

The research team also discovered that approximately 40 percent of kitchens visited in these three countries had chronic gas leaks, meaning gas was escaping even when stoves were switched off. When researchers combined this leak data with benzene concentration measurements, they found that 9 percent of homes in the UK, Netherlands, and Italy had leaks large enough to exceed regulatory exposure limits for benzene. Even more concerning, 14 percent of homes exceeded the stricter WHO lifetime guidance level.

How Are People Being Exposed Without Knowing It?

One of the most troubling aspects of this discovery is that residents have virtually no way to detect these dangerous leaks. Gas companies add sulfur-based odorants to natural gas to help people smell leaks and avoid explosions. However, the researchers found that odorant levels in all tested regions outside Italy were far too low to alert people to leaks large enough to create hazardous benzene concentrations indoors. In the United Kingdom, benzene exposure could rise nine times above the national limit, and nearly 40 times above the limit in London, before a person could smell the leak at average odorant levels. In the Netherlands, exposure could reach nearly five times the EU limit, or 15 times in Amsterdam, before becoming detectable by smell.

"We were surprised by how high the benzene levels were compared to what we've seen in our previous studies. Given these high concentrations, a lot of people are likely being chronically exposed to benzene without knowing it," said Tamara Sparks, PSE air quality scientist and lead author of the study.

Extrapolating these findings to the broader population, researchers estimate that hundreds of thousands of people, particularly in the UK and Netherlands, are likely exposed to benzene above regulatory limits. The modeled benzene exposure from larger leaks in these two countries is worse than living with a smoker, in terms of benzene exposure alone.

Steps to Reduce Your Personal Benzene Exposure at Home

• Increase Ventilation: Open windows regularly to get fresh air circulating through your home, especially in kitchens where gas stoves are used. This helps dilute any benzene that may be leaking from your gas supply or appliances.
• Have Gas Appliances Inspected: Request a professional inspection of your gas stove, furnace, and other gas-powered appliances to identify any leaks. Many utility companies offer free or low-cost leak detection services.
• Monitor for Gas Odors: Familiarize yourself with the smell of natural gas (the sulfur-based odorant added by gas companies). If you notice any unusual gas smell, contact your gas provider immediately, even if it seems faint.
• Consider Alternative Cooking Methods: If you live in a high-benzene region, explore electric or induction cooktops as alternatives to gas stoves to eliminate one potential exposure source in your home.

The research also examined a major pipeline leak that occurred in the UK in 2023. Modeling showed that at its peak, this incident lifted benzene concentrations four times beyond an EU eight-hour worker safety limit up to 50 meters downwind, with lower levels predicted as far as 10 kilometers away. This single event potentially exposed tens of thousands of people in Cheltenham and Bishops Cleeve to dangerous benzene levels.

"The levels of benzene we found in the distribution system gas in the UK and the Netherlands are frankly eye-popping. That means even a small leak can pose significant health risks quickly indoors and outdoors," stated Seth Shonkoff, PSE executive director.

What Does This Mean for European Policy and Your Health?

This research represents the first comprehensive study to reveal the widespread presence and health risk of benzene in European home gas supplies. It follows a similar discovery in North America and is part of PSE's broader Methane and Health Initiative, which assesses air pollution and health risks from known methane sources. The findings suggest that safeguarding the public from benzene exposure in Europe will require fundamentally rethinking our relationship with natural gas as an energy source.

The study was funded by the European Climate Foundation and the Wellcome Trust, organizations committed to understanding and mitigating environmental health risks. The research underscores the importance of science in identifying previously unrecognized exposure pathways and informing policy decisions that protect public health. As chemical production is expected to double by 2030, understanding how chemicals enter our homes through everyday sources like gas supplies becomes increasingly critical for protecting population health.

For now, the most practical step individuals can take is to increase ventilation in their homes and have gas appliances professionally inspected. However, the broader solution will require policy action to either improve odorization standards so leaks become detectable, or to accelerate the transition away from natural gas toward cleaner energy alternatives.