Greenhouse gas emissions have a new culprit: asthma inhalers

Concerns about the carbon footprint of healthcare typically revolve around issues such as over-air-conditioned hospitals and waste of single-use medical supplies. But researchers like Jyothi Tirumalasetty of Stanford University think asthma inhalers are also a good start when it comes to reducing emissions.

Metered-dose inhalers, the most common type used to treat asthma or chronic obstructive pulmonary disease (COPD), use a propellant to aerosolize medications, which patients then inhale. These propellants are usually one of two different fluorocarbons – and there are many. times better at trapping heat in the atmosphere than carbon dioxide, thus contributing disproportionately to climate change.

Allergist Tirumalasetty, along with University of Michigan professor Shelie Miller and other co-authors, analyzed 2022 data from Medicare and Medicaid to find out the average greenhouse gas emissions of these inhalers and compare their costs with more environmentally friendly options.

STAT spoke to Tirumalasetty about the research, published today in JAMAand what the takeaways are for people who use inhalers.

This interview has been lightly edited and condensed for length and clarity.

Broadly speaking, are inhalers a major contributor to climate change?

Our figures showed that for the year 2022, that amount of emissions applies to the Medicare-Medicaid population [from inhalers] is equivalent to providing power to all the homes in a city about the size of Milwaukee for an entire year.

HHS has agreed that they want to reduce [emissions] by 50% by 2030 and by 100% by 2050. And many institutions have signed that pledge. And where do we start with reducing healthcare emissions? We know that healthcare represents approximately 8-10% of our national emissions annually. And so even though this is only a fraction of that, it’s a good starting point.

What has the research yielded?

We mainly prescribe metered dose inhalers. These are the inhalers that contain the propellants of greenhouse gases, and those inhalers contribute about 98% of the emissions of all inhalers. And we spend much more on environmentally friendly alternatives; the majority of these would fall into the category of dry powder inhalers.

We find that CMS has spent $2.5 billion more on these dry powder inhalers, even though they are prescribed far less frequently than the propellants.

I thought – perhaps naively – that hydrofluorocarbons (HFCs) had been phased out a few decades ago.

Those are CFCs [chlorofluorocarbons] – the Montreal Protocol has phased these out [in the early 2000s]. We’ve taken them out of inhalers and replaced them with HFCs. So the CFCs were destroying the ozone layer. And the HFCs are greenhouse gases that trap heat thousands of times more powerfully than carbon dioxide – they have a much higher global warming potential than carbon dioxide.

So we went from one not-so-great propellant to another not-so-great propellant – or propellants, I should say, since there are two used in these inhalers. That’s why [some inhalers] have super high emissions compared to others; it really varies widely within these metered dose inhalers. There were a few with emissions of about 15 [kilograms of estimated carbon dioxide equivalents per inhaler] and then others who were about 48. So even within that there are definitely better choices. It’s not like everyone has to go to a dry powder. We could even reduce our emissions by continuing [to] metered dose inhalers with lower emissions.

And maybe zero-emission propellants are on the way… so that’s much better for the environment. It’s just that [when we get the new inhalers] – and this happened when we saw the CFCs disappear and the HFCs come – they rename the inhaler, they sell it under the new brand name, and then it becomes more expensive and it gets a higher level of insurance coverage, and we think that this is the case. It will take some time before these are accessible to everyone.

Is it even safe for people to inhale these fluorocarbon propellants?

It’s safe. When you use [an inhaler]the medicine enters your lungs. But most of that propellant will come back out when you exhale it. And so, whether you spray it into the air or inhale it and exhale it, it goes into the atmosphere and ultimately traps heat. It is not harmful to the ozone; it is not a pollutant that is harmful to us. It retains heat and increases the warming effect of the atmosphere. And that’s where the problem lies.

It will also remain in the inhaler after you have finished using it; approximately 30% may remain behind. If you throw it in the trash, it will slowly drain over time. There are currently no recycling programs for inhalers in the US… There is a place in the UK that does: they reuse the greenhouse gas and [sell it back to] the heating and cooling industry. And some places can actually recycle the aluminum can and some places can recycle the plastic. [but] that’s really not done on a large scale in the US

Besides costs, are there reasons why the more environmentally friendly inhalers are prescribed less?

I am an allergy immunology doctor. I’ve been treating asthma for 20 years now, and I think some of it has to do with cost, some of it has to do with patient preference, some of it has to do with just tradition: “Hey, this inhaler has been around for a long time.” long. This is what we are used to. That is why we are going to prescribe this.” Even though some of these newer inhalers, the dry powder inhalers, are a lot easier to use for a lot of types of people and they’re designed so that you only have to do them once a day so they lead to more compliance versus a lot of the older metered doses .

Other countries have now really switched to using dry powder as they try to reduce their emissions. In Britain, they have implemented programs across the country to reduce the use of inhalers containing propellant. And the same goes for Canada. I think the UK, last time I checked, was about 50/50, so they have reverted to using inhalers that contain propellant. In Sweden, this concerns approximately 80% of dry powder and mist inhalers, which do not contain propellants.

I think if we are more aware that there are other options, if we are more aware that the options we use a lot are not good for the environment, I think people would be more willing to consider other options to consider.

What would a move to shift look like? Is it a policy change? Is it its priority? [prescription drug] Forms, is this a medical training course?

I think it’s all those things. And when I speak to people practicing in the UK, they tell me that their patients know that these inhalers are not good for the environment and that they have invested in reducing their own carbon footprint, and they are asking for environmentally friendly inhalers . .

This is not something we would recommend for small children. We know there are limitations for people switching to eco-friendly inhalers. It [depends on] whether or not they can breathe deeply… And we don’t have great studies comparing dry powder inhalers to metered dose inhalers, the eco-friendly to the non-eco-friendly. We don’t have any recent strong studies in the US that can really clearly delineate which one is better, which one is easier to use.

But I would say that such a program really requires educating physicians to ensure that they make the decision together with their patients – to ensure that the patient, if he or she has a preference, does not inadvertently change his or her choice. We don’t want a patient to feel bad or be forced to switch. We don’t want anyone not to have access to their asthma inhaler. We want to use what is best for them and what is best for the environment, whenever possible.

What is the conclusion of this research? Is it up to doctors to look at the chart you have and figure out how to prescribe lower emission inhalers to their patients?

Absolute. We want to reduce our emissions in healthcare, and we want to analyze what we’re doing and say, “Hey, at what step can we reduce our emissions?” And if there’s an easy way to do that where we don’t compromise care, so we choose the best inhaler for the patient and the best inhaler for the environment, whenever possible, then that’s what we’d like to see people do. .

And we want to be very upfront about, “Hey, this may lead to higher spending on these inhalers because these dry powder varieties and these gentle mist varieties tend to be more expensive; We’re not sure why that is.” But we know that they are very effective medications and many places have switched to them and are having great results. That’s really the takeaway. And everything we do in medicine – whether it’s in the OR, or in anesthesia – we’re starting to think about the environmental footprint of healthcare, because a lot of people aren’t having those discussions.

We also hope that this will lead to some policy changes – that perhaps the Centers for Medicare and Medicaid Services, under the Inflation Reduction Act, can negotiate better prices for eco-friendly inhalers, which will provide an incentive for people to prescribe them more.