NATIONWIDE STUDY FINDS THAT LEAKS IN NATURAL GAS PIPELINES

New research finds that methane leaks in energy-intensive states like Texas lower the air quality for people in neighboring states

Embargoed for Release Until June 4, 2025   

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Herndon, VA, June 4, 2025 — In March 2022, 14 residents of a four-story apartment building in Silver Spring, Maryland, were hospitalized when a gas leak from a cut pipeline caused a major explosion. Every year in the United States, there are hundreds of natural gas (or methane) pipeline leaks — caused by corrosion, equipment malfunctions, and construction activities. Methane leaks are not only dangerous; they contribute to air pollution and climate change.

A nationwide study of gas leak incidents, published in Risk Analysis, has revealed that gas leaks in one state have measurable impacts on neighboring states. For example, gas leaks in Texas, a state with extensive pipeline infrastructure and frequent incidents, were found to raise levels of PM2.5 in neighboring states like Oklahoma and Louisiana. (PM2.5 is a dangerous form of air pollution known as fine particulate matter, known to cause respiratory and cardiovascular issues when inhaled.)

“Pollutants like methane and its by-products (PM2.5) travel across state borders,” says Younes Ben Zaied, co-author of the study and professor of finance and sustainability at EDC Paris Business School. 

He and colleagues used spatial econometric modeling to analyze the impacts of gas leak incidents from 2009 to 2019 in all 50 states, recorded by the Pipeline and Hazardous Materials Safety Administration (PHMSA). Included in that database are the 2015-2016 Aliso Canyon Leak in California (one of the largest methane leaks in U.S. history); the 2018 Merrimack Valley Explosions in Massachusetts, which impacted over 40 homes; and numerous New York City underground leaks. Other data used in the analysis were annual average PM2.5 concentrations (for every state) over the same 10-year period from the Social Economic Data and Application Center (SEDAC) at Columbia University’s International Earth Science Information Network Center (CIESIN).

The results demonstrated that:

• PM2.5 levels in a state are influenced by the energy intensity of neighboring states. For example, Illinois has moderate energy use per GDP but is surrounded by states like Indiana and Kentucky, which rely more heavily on coal and fossil fuels. This means that PM2.5 levels in Illinois can be partially explained by the energy consumption patterns of its neighbors. 
• Stringent environmental regulations are shown to reduce hazardous gas leaks and improve safety. Examples of high-performing states are California, New York, and Massachusetts. These states had lower reported leak incidents over time, higher pollution control investment per unit of industrial output, and beneficial spillover effects on neighboring regions, encouraging cleaner practices.

“We were surprised to find that even states with strong environmental regulations and cleaner energy practices are still affected by the energy intensity of nearby states,” says Zaied. “For example, an energy-efficient state with low energy consumption per GDP may still suffer from elevated PM2.5 levels if neighboring states are energy-intensive and leak-prone. So even if your state is doing everything right, gas leaks in neighboring states can still worsen your air quality.”

The message, adds Zaied, is that “cleaner air and safer infrastructure require interstate collaboration, not just local solutions.”

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