While smog billowing from factories and exhaust from vehicle tailpipes are among the more visible forms of air pollution, another source is almost impossible to see with the naked eye. But out of sight isn't out of mind for concerned researchers. 

What's happening?

According to a study summarized in The Conversation, invisible methane leaks are pushing out pollutants that trigger asthma, heart problems, and other serious health risks. 

The danger doesn't stay at the source. In Massachusetts, a 2018 pipeline explosion put about 2,800 metric tons (nearly 3,100 tons) of methane into the air. Within a few weeks, air monitors detected increased pollution levels in Vermont and New Hampshire. 

But it isn't just notable explosions that are the problem. Smaller gas pipeline leaks are also releasing a significant amount of methane. 

The researchers estimated that "undocumented small leaks in the U.S. may total on the order of 15,000 metric tons [about 16,500 tons] of methane per year."

Why is methane concerning?

In addition to the widely known concerns about methane — such as its role in trapping heat in the atmosphere, which increases global temperatures and exacerbates extreme weather events — it also reacts when exposed to other gases, like nitrogen oxides and sunlight, to create what the researchers call "secondary organic aerosols." 

These aerosols comprise a significant portion of the air's background PM2.5, particulate matter that can enter the body and increase the risk of cardiovascular and respiratory diseases. There is no safe level of PM2.5 exposure, as the American Lung Association has suggested. 

Those undocumented small gas leaks are "enough to raise background PM2.5 by roughly 0.1 micrograms per cubic meter in downwind areas," according to the researchers, per The Conversation.

What can be done about methane?

The researchers suggested that pipeline methane leaks can be avoided by using materials or processes that are less likely to release gas. 

"Regulations could create incentives to do so or require companies to invest in technology to detect methane leaks quickly as well as encourage rapid responses when a leak is identified, even if it appears relatively small at first," they added. 

Do you worry about the quality of the air inside your home? Yes — often 😬 Yes — but only sometimes 😕 Only when it's bad outside 😮‍💨 No — I never do 😌 Click your choice to see results and speak your mind.

Updated air quality standards now take PM2.5 more seriously. Meanwhile, satellite technology is being used to detect methane hot spots before they spiral into public health crises.

At home, exposure to natural gas can be reduced by switching from a gas-powered stove to an electric induction version. Not only can an induction stove cut indoor air pollution, but it can also save people money on energy bills while making cooking cleaner, safer, and faster. 

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