Propellants in regularly prescribed inhalers are accelerating global warming

New reports reveal the most commonly prescribed inhaler in the U.S. may actually be contributing to climate change.

While these inhalers are critically important to saving lives and making it easier to breathe, a Stanford-led study is showing that there are easier, less polluting options.

For Shelbi Inan, breathing easy is not always so easy to do.  At the age of 13, she was diagnosed with asthma . Since moving to California, her asthma appears to have worsened.

"More often than not, I'm wheezing. I have heavy lungs. It's hard to exercise. And it just makes my life harder," explained the mother of 2.

There is no cure for asthma, but there is treatment. Inan uses a handheld inhaler.

Doctors also prescribe them to patients with chronic obstructive pulmonary disease or COPD for short, as well as other lung diseases.

"They've very important. They are lifesaving medications. And they are medications that have been shown to improve quality of life," said Dr. Jyothi Tirumalasetty .

Dr. Tirumalasetty is a clinical assistant professor at Stanford University School of Medicine and an allergy-immunology specialist.

New research led by Dr. Tirumalasetty reveals how the most prescribed inhaler in the United States may contribute to climate change . These "metered-dose" inhalers look like a little boot.

The propellants aerosolize the medicine and help bring the treatment into the lungs. But they are also a problem when it comes to our warming planet.

"Those propellants are known as HFCs or hydrofluorocarbons ," said Tirumalasetty. "And they can cause worsening global warming because they trap heat in the atmosphere, and they trap it 1000s of times more powerfully than carbon dioxide ."

The research letter is published in the Journal of the American Medical Association or JAMA for short.

The researchers looked at the three main types of inhalers:  the metered dose, the soft-mist, and the dry-powder. They also calculated how many prescriptions for each type of inhaler is written each year for the Medi-Cal and Medicare programs.

They discovered while the metered doses contain the highest levels of hydrofluorocarbon, the levels vary from brand-to-brand.

Each metered-dose inhaler releases on average more pollution than a car traveling at 60 mph. With 70 million prescriptions written every year in the U.S. for the federal health care programs, they release more emissions that 200,000 homes powered by electricity in a year.

Some patients, especially very young children, should stick to metered dose inhalers. But other patients can talk to their doctor if interested in switching to a different brand or a different type to see if it's medically advisable.

"The first thing to consider is switching to one with a lower carbon footprint if you need to stick to a metered-dose inhaler," explained Tirumalasetty. "And the other option would be to switch to a dry-powder inhaler, which contains no propellant, or a soft mist inhaler, which contains no propellant,"

The Stanford doctor also noted how difficult it is to recycle metered dose inhalers. At times, a lot of the potent greenhouse gas remains in the canister, and when its tossed, it goes into landfill where it slowly leaks out.

Another question to consider is if switching would be affordable. Some brands are more expensive, but insurance could help. Even with their findings, Dr. Tirumalasetty says do not stop using your life-saving inhaler.

As for Inan, she is now using the dry power inhaler. She is aware of the factors influencing the warming of the planet and would like to try a different type of inhaler, which has a smaller carbon footprint.

"It may be better for the environment," she said with a smile.

The United Kingdom, Canada, and Sweden have already implemented programs to encourage primary care providers and specialists to switch to different types of inhalers. Dr. Tirumalasetty explained patients in those countries who switched to different types of inhalers such as the soft mist or dry powder did well on them.

She said the big unanswered question in the United States was the cost of switching, since the United States does not have nationalized health care.