Breathe easy: The hidden health impacts of gas

[Anthony] (0:00 - 0:04)
About 12% of all childhood asthma is due to gas use in homes.

[Sarah] (0:09 - 1:03)
Welcome to the Good Energy Guide. No jargon, no guesswork, just better energy choices. Brought to you by Ausgrid, electricity distributor for Sydney, the Central Coast and Hunter region.

I'm your host, Sarah Aubrey. Today we're talking about something most people never think about, the hidden health impacts of gas. From cooking and heating at home, to the gas burned in our streets and communities, these pollutants affect the air we breathe every day.

We'll explore what those pollutants actually are, how they impact children, people with asthma and other vulnerable groups, and why symptoms can often go unnoticed or misattributed. To help us unpack this, we're joined by Dr Anthony Hull from Doctors for Environment Australia, one of the leading medical voices on health and climate. Welcome, Anthony.

[Anthony] (1:03 - 1:03)
Thanks for having me, Sarah.

[Sarah] (1:04 - 1:09)
Now, many people think that air pollution is only an outdoor problem. Why is that not the case?

[Anthony] (1:10 - 1:21)
Well, unfortunately, indoors we have an enclosed environment and there are lots of reasons why pollutants can be released into the indoor environment in our homes. And our homes aren't very leaky, especially these days.

[Sarah] (1:21 - 1:23)
Can you explain that, what a leaky home means?

[Anthony] (1:23 - 1:55)
Well, a leaky home, in the old days, there were cracks and crevices, and people weren't too concerned about energy efficiency or insulation. Whereas now, by regulation and also because people are more aware of it, our homes are much more effectively insulated, cracks are sealed up, building codes are better, which encloses the internal air inside those spaces more effectively. But it means that concentrations of things that shouldn't be there build up far more effectively as well.

And then we get exposed to those in our sleep and while we're awake and we're spending most time in our homes.

[Sarah] (1:56 - 2:06)
That sounds great. A cocktail of fun. Can you explain how gas used in our kitchens and heaters and even burned across our communities influence air quality?

[Anthony] (2:06 - 2:30)
Yeah. So, burning gas unfortunately releases several pollutants and that's because of the combustion process and the interaction of that burning process with oxygen. So, you get things like nitrogen dioxide, carbon monoxide, formaldehyde and benzene that are being released into the air.

And even when you're not combusting gas, gas can leak.

[Sarah]
From your stove?

[Anthony] 
It can leak from your stove or from other gas appliances in between times.

[Sarah] (2:30 - 2:41)
That is shocking. They're turned off for significant periods of time. I don't think many people realise that.

Some of those toxic things that you're talking about, what kind of effect do they have on the human body?

[Anthony] (2:41 - 4:10)
Well, all of them can have substantial effects. I'd probably have to go through one at a time. Ideally, if you look at nitrogen dioxide, otherwise known as NOx, because it exists as nitrogen oxide and nitrogen dioxide, but they interchange.

So, this has been studied for decades, and it's well known that it causes health harm. It's just that for a long time, it hadn't been studied that much indoors. But what has been studied in the recent couple of decades is how much it builds up inside from burning gas.

So, there's significant exposure to nitrogen dioxide in homes from gas use. Studies looking specifically at those effects point out more regularly than other things, asthma, lower respiratory tract infections, even the development of pneumonia in people who live in those homes, that being an increased risk because of the exposure to that pollutant. And even just symptoms, a cough or a bit of a wheeze.

And it can affect adults and children, but probably the worst effect is on children who live in those homes, but still substantial effects on adults. So that's nitrogen dioxide. Carbon monoxide is caused from incomplete combustion.

And that's common and normal when you're burning anything. And carbon monoxide can cause acute effects like death from high levels of exposure. And that happens regularly in Australia, even now.

Or it can cause longer term, lower grade exposure-related effects like poor memory, irritability, changes to behaviour and personality, which sounds quite startling.

[Sarah] (4:10 - 4:12)
Sounds quite common, that one really, doesn't it?

[Anthony] (4:13 - 4:25)
Yeah, I get it all the time, even though I don't use gas in my house. But, you know, this is an important problem. But the biggest issue with that is that it's not very commonly diagnosed or even thought about from a medical point of view.

[Sarah] (4:25 - 4:26)
So, it could be misdiagnosed as well.

[Anthony] (4:27 - 4:30)
Definitely misdiagnosed or not even considered.

[Sarah] (4:30 - 4:34)
Just sort of, oh, well, that's how I am. What about some of the other ones?

[Anthony] (4:35 - 5:12)
So, benzene is probably the one I'd like to speak of next. And that's a well-known carcinogen that causes hematological or bloodborne malignancies and cancers. So, levels of benzene from a burning flame, but also from raw gas that leaks from your stoves can actually cause concentrations that are above acceptable levels by World Health Organisation or even organisations like the EPA in the United States, above those levels that are deemed acceptable.

So, some researchers recently showed that there's a significantly increased risk in their modelling of a child developing leukemia, for example, in a home that uses gas appliances.

[Sarah] (5:13 - 5:16)
That's shocking. Was there one more?

[Anthony] (5:16 - 5:41)
Yeah, formaldehyde. The problem with formaldehyde is it's an irritant and it's also a carcinogen. It's probably not as well researched in the home setting in regards to how much increased risk there is from exposure to that carcinogen, but it's a problem and it can cause acute symptoms as well, just as benzene can cause acute symptoms that I didn't mention, like irritability and tiredness and headaches.


[Sarah] (5:42 - 5:49)
Wow.

With those four pollutants, when do they occur in the process? Is it just when I turn the stove on? Or, as you said, is it more when they're leaking?

[Anthony] (5:50 - 6:12)
Well, it's throughout the process. So, for example, if you're burning a gas flame, then they'll just gradually build up more and more inside your home environment. There's no particular part of the cooking process that will yield more or less of the carbon monoxide, for example, or the nitrogen dioxide.

It just is continually produced while the flame is burning, either in a heater, in an oven or in a stove.

[Sarah] (6:13 - 6:17)
That's just terrifying. Does a stove come with a warning label when you buy it?

[Anthony] (6:17 - 6:49)
No, it doesn't, which is very unfortunate, but there is a letter which has been penned and not sent to anyone. It's more of a position statement that's been co-endorsed by the Royal Australasian College of Physicians, the Australasian College of Emergency Medicine Specialists and Doctors of Environment Australia, which actually calls for disconnections of homes from gas and a cessation of rolling out gas connections, but also warning labels to be at every point of sale for gas appliances, so that people are aware when they're buying them.

[Sarah] (6:49 - 6:51)
Even on your bill, your gas bill?

[Anthony] (6:52 - 6:56)
That would be the ideal, that they get a reminder. 

[Sarah] (6:56 - 6:57)
Yeah, like a pack of cigarettes, right?

It's got a warning on it.

[Anthony] (6:57 - 6:58)
Yeah, correct.

[Sarah] (7:00 - 7:09)
Anthony, this is terrifying. Okay. Roughly what percentage of Australians, or how many Australians, suffer from asthma?

[Anthony] (7:09 - 7:58)
I can’t give you an exact number for that except to say that in children, it's the number one cause of disease, of chronic disease. We call it a burden of disease.

Then in adults, it's about the fourth on the list. It really hits high in terms of morbidity in the Australian community. It causes a lot of time off from school, time off from work.

It causes suffering. People who are asthmatic actually report high levels of dissatisfaction with their life in general. About 50% of asthmatics are only poorly controlled.

We have this image that asthma is very well controlled in Australia because we're a modern country, but unfortunately, that's not the case. 50% of hospital admissions for asthma are for children with asthma. It really hits us hard in that important part of our lives, which is our children.

[Sarah] (7:58 - 8:09)
You could be doing it to your kids just by using a gas stove or a gas heater. 

[Anthony]
That's right.

[Sarah]
That is really scary.

What would you like families to know about indoor air quality that often gets overlooked?

[Anthony] (8:09 - 8:19)
I think to be aware of it and to be aware of the causes of it, in particular causes they can change themselves and they can change fairly quickly. In this case, gas, use of gas in their homes.

[Sarah] (8:20 - 8:37)
Actually, we will talk about that. We'll talk about some solutions because we're focusing on the problem. We will talk about solutions and ways that you can mitigate that.

Before we get to solutions, are these the same pollutants that come from the tailpipes of petrol and diesel vehicles?

[Anthony] (8:38 - 8:47)
Yes, they are. The only difference would be that vehicles in addition to these pollutants also emit things called PM2.5 or small particles of matter.

[Sarah] (8:47 - 8:48)
There's more.

[Anthony] (8:48 - 9:14)
So, you get double the bang for your buck with a motor vehicle, albeit they're outside and in the outside environment, those pollutants come out of the tailpipes. They're a major problem. The similar pollutants to those released from gas are a major problem coming from vehicle exhausts as well.

That's been incredibly well researched as well. Same pollutants, same effects on health, but in an enclosed environment when you're burning your gas in your house.

[Sarah] (9:14 - 9:16)
We really do treat our air like an open sewer, don't we?

[Anthony] (9:16 - 9:17)
We do.

[Sarah] (9:17 - 10:27)
Isn't it amazing? If we had polluted water, if right now the water coming out of your taps was discovered to be polluted, everyone would be up in arms. There'd be government inquiries because it's something that we ingest, but we ingest air.

Air goes into it. We're breathing that in, but we seem to just accept that this is how it is, that we drive vehicles that you can't run them in an enclosed space because they are so dirty and dangerous. With the gas stove, and in particular the gas heater we had in our house, which was unflued, I experienced a whole bunch of those symptoms, dizziness, sleepiness, headaches.

I always had this runny nose, blocked nose. And as soon as we, when we actually electrified the house and removed gas, it was summer, so we weren't using the gas heater. The minute we took that stove out of the house, which was from the 1990s, so guaranteed it would have been leaking.

As soon as that was disconnected and taken out of the house and we put the induction stove in, the air in the house completely changed. I could breathe better. The blocked nose went, no more sleepiness, no more headaches, no more, none of those symptoms, all gone.

So, it absolutely was the gas.

[Anthony] (10:27 - 11:11)
Yeah. And that's not surprising. There was some research done on schools in New South Wales, not so long ago, looking at the effect of unflued gas heaters in school classrooms.

And they did a trial where they looked at kids' respiratory symptoms, including things like that, a bit of a cough, feeling a bit short of breath or wheezy, having a blocked nose, general respiratory symptoms. And they had a period of time where they would document that when an unflued heater was being used in the school, which was the normal situation. And then they had a flued, properly vented heater moved in the place of those heaters for another period of time.

And no one knew which heater was being used, but the difference was significant in that symptomatology. And that unleashed a wave of replacements of heaters in schools across this state.

[Sarah] (11:11 - 11:14)
Wow. Are they still using unflued gas heaters in schools?

[Anthony] (11:14 - 11:36)
Unfortunately, yes. The process started with gusto and then slowed down a little bit. I think where it was left was that the remaining 1500 or 2000 schools or so will wait until end of life for those heaters.

But unfortunately, although other states have moved and replaced them completely throughout their public schooling sector, in New South Wales, it's not quite the case yet, which is very unfortunate.

[Sarah] (11:36 - 11:40)
Well, does that actually affect kids' ability to concentrate as well in terms of learning?

[Anthony] (11:40 - 12:09)
I'm not aware of a specific study looking at that, except that air pollutants in general, for example, from traffic and idling in front of schools has been shown to potentially affect academic performance and also behaviour of students in class. So, it wouldn't be a long to draw that kids who are a little bit sick from respiratory symptoms and are being exposed to those pollutants, including what could be carbon monoxide that causes drowsiness or headaches. It's not very hard to imagine that could be the case.

[Sarah] (12:09 - 12:20)
So, on top of poor air quality inside schools, you've got a whole bunch of schools that are on busy roads and childcare centres that are in very prominent positions on busy and polluted roads.

[Anthony] (12:20 - 12:28)
Correct. And we don't regulate that or look at that very closely here, whereas other jurisdictions internationally would actually be looking at that very closely when they design their schools.

[Sarah] (12:28 - 12:47)
And on top of that, we have parents idling outside schools to pick up their children. I think in Australia, we think we have fairly clean air. We look at cities overseas that are covered in smog and we think it's pretty good here.

In terms of asthma, especially amongst children, where does Australia sit? Are we high? Are we low on the list?

[Anthony] (12:47 - 13:09)
We have a relatively high incidence of asthma in Australia. About one in 10 children have asthma. Unfortunately, the estimate is that about 12% of all childhood asthma is due to gas use in homes.

12%? That's right. So, anything we can do to reduce the amount of asthma we have is going to give big benefits to Australia as a whole.

[Sarah] (13:10 - 13:25)
It's just so scary to think that you could have something that you think is so innocuous in your home that's causing that in your child. And so many people are very attached to their gas stoves. It does seem to be a thing.

How do we balance that really, isn't it?

[Anthony] (13:25 - 13:51)
If we tried to implement gas into homes now and our baseline was that every home was electric, I'm sure that people would raise an eyebrow and say, well, why would I pipe gas, which is a toxic substance, into my home and then burn it in my kitchen? It's like I don't have a campfire in my kitchen either. So, I think that would be a real way to change it around and look at it from that aspect.

I think it's just basically habit, partly, and culture.

[Sarah] (13:51 - 14:02)
And there was a massive push to put gas into homes because it was cheaper than electricity. So, we're now living with the consequences of that, aren't we? But people are getting off gas, aren't they?

[Anthony] (14:03 - 14:18)
Yeah, they are. Most things that I read nowadays is that gas use in homes is... 

[Sarah]
It's dropping.

[Anthony]
Yeah, it's dropping because of cost. I don't think there's much of the health reasoning in there yet because the awareness is still very, very low. But certainly, because of cost and for some other reasons, perhaps.

[Sarah] (14:19 - 14:39)
It's just cheaper if you electrify your house. I eliminated my gas bill, got rid of gas, and that was back in 2022, $900 saving. And then gas has gone up 40% or something since then.

It's gone up a great deal anyway. So, it'd be well over $1,000 saving every year now just from not having that in the home.

[Anthony] (14:40 - 14:46)
Yeah, and not uncommonly, most of your bill is the connection fee as well. If you're not a large user of gas, the connection fee is the bigger part of the bill.

[Sarah] (14:46 - 15:09)
Okay, that's a very clear picture of the health impacts, which is slightly terrifying and a cocktail of fun. Now let's talk about the practical steps that people can take to reduce their exposure. Let's talk about solutions.

I love solutions. First and foremost, what are the easiest changes people can make today, right now, to improve the air quality inside their homes?

[Anthony] (15:09 - 15:33)
Well, you could buy a plug-in induction stove. They're very easy to get. 

[Sarah]
They're not very expensive.

[Anthony]
They’re very affordable, and they even look really good too.

And you can get single or double hob versions of those. The double hob versions are around maybe $200. You plug it right in.

You can put it where your stove currently is, if you have a gas stove, put a nice flat surface on there.

[Sarah] (15:33 - 15:48)
Yes, I've seen people with a breadboard or something like that on top of their stove. And that's great for renters as well, because you can often feel very disempowered that you can't do things to a home. So, if money is the problem, or that you don't own the place, that's...

[Anthony] (15:48 - 15:57)
Often in apartments, you don't need four hobs for cooking, and there aren't as many people living in there. So, a single or double hob plug-in stove would be perfect.

[Sarah] (15:58 - 16:00)
Yeah, great. What else could we do as a solution?

[Anthony] (16:01 - 16:17)
An air fryer. You could buy an air fryer. We just bought another one the other day.

They're just so fantastic, and they're getting safer now. You can get the glass ones that don't have any chemicals in them. Plug that in, put that on top of your stove as well.

And then unless you're doing a really big cook-up in your gas oven, then you don't have to use a gas oven potentially.

[Sarah] (16:17 - 16:21)
Okay, so we've talked about a portable induction stove, air fryer, anything else?

[Anthony] (16:22 - 16:51)
I think the next easiest thing would be to swap out your gas heating for a reverse cycle air conditioner that can cool your home and heat your home as well. They're generally not so expensive as doing a full change out of your house from gas to electrical. And you don't necessarily have to get your gas heater disconnected.

If you don't want to, you can just have it there and not use it. But that would be another relatively simple way to reduce your exposure to potential pollution from gas heaters in your home.

[Sarah] (16:52 - 16:57)
And what about things like opening a window when you're using gas stoves and stuff like that?

[Anthony] (16:57 - 17:09)
Oh, absolutely. So, I mean, the minimum recommendation if you're cooking with gas in your home is that you have a rangehood that's functional and is being maintained, that it is ducted to the outside of your house.

[Sarah] (17:09 - 17:11)
That is not the norm.

[Anthony] (17:11 - 17:14)
Believe it or not, it's not uncommon that it's ducted inside your own home.

[Sarah] (17:14 - 17:20)
As it was in my kitchen before I changed it. To the top of the cupboard, so useful. Not.

[Anthony] (17:21 - 17:29)
And it needs to be an effective rangehood as well. And you should be using it on its maximum function, which means you generally can't talk to people while you're cooking because of the noise.

[Sarah] (17:29 - 17:30)
And people aren't going to do that.

[Anthony] (17:31 - 18:01)
A lot of people don't. And even where they are present, some studies have shown usage is as low as 35% of rangehoods. For all of those reasons, they're noisy.

[Sarah]
They are noisy. 

[Anthony]
You forget. But you also have to have a window open to make them relatively effective.

Because otherwise you're creating a negative pressure inside the house and not really ventilating very effectively. But as we know, in summer and winter, you don't really want to open your windows. So that's something a lot of people wouldn't do as well.

But it's something you can do to reduce the harm.

[Sarah] (18:01 - 18:03)
True. And it costs nothing.

[Anthony] (18:03 - 18:09)
And only cook on the back of your gas stove, if at all possible, so that it's more likely that the fumes go up into the rangehood.

[Sarah] (18:10 - 18:13)
Right.

That's a good point.

Anything else, solutions wise?

[Anthony] (18:14 - 18:21)
To the gas issue. Well, you can just change to 100% electric house.

[Sarah] (18:21 - 18:23)
Just electrify your house and get off gas.

[Anthony] (18:24 - 18:25)
Have cheaper energy bills.

[Sarah] (18:25 - 19:31)
Or work your way towards that. Because you do save, obviously, on those gas bills. You're not getting gas bills anymore.

So that is an immediate saving when you do electrify your house. But I think also it's important for people to remember that if money is an issue and you're stressing about these things, just do it over time. Because you can't even do things like close up all the gaps.

We're talking about leaky houses. You can't close up all those gaps and cracks in your home until you get rid of that gas stove or heater, the gas from inside your house. You can still have outdoor hot water that's on the outside of your house, but you can't do those things, which you can do really cheaply yourself.

You can't do that stuff if you've got gas inside the house. So, if you eliminate that, you can then go and close up all those gaps and cracks, which will make your house much more comfortable to live in as well. And you'll save money on energy bills just from that as well.

Because you're not going to be losing all your lovely cooling and heat through all those gaps and cracks. Okay. Well, there's some solutions.

I mean, look, I love an induction stove. So that would be my first port of call. And that's quick and easy, right?

So that's good.

[Anthony] (19:31 - 19:33)
Super good. They look super great and they’re easy to clean.

[Sarah] (19:34 - 19:39)
So, we talked about gas appliances. How do electric appliances reduce exposure to pollutants?

[Anthony] (19:40 - 20:02)
So, because you're not burning something in your home, in this case, gas, you're not producing the pollution from that combustion process. All you're doing is applying heat to the food and to the cooking utensils. And that heat, it's interesting to point out that that heat is very directed on the cooking process compared to gas when about two thirds of the heat actually is released into the air around the kitchen.

[Sarah] (20:02 - 20:04)
Because it's going sort of around the pot.

[Anthony] (20:04 - 20:13)
That's correct. So, a lot of wasted energy. It's like petrol cars versus electric vehicles.

Most of the energy in the petrol car variety is wasted.

[Sarah] (20:13 - 20:14)
To heat.

[Anthony] (20:14 - 20:44)
To heat. Yes, that's right. And then so in the home, the same thing, the heat from the gas is wasted energy, whereas electric appliances are far more efficient and effective because they're directed at the food.

The other issue with cooking, though, that's worth mentioning is that pan frying, cooking food at very high temperatures, whether it's gas or electric, can release pollutants of its own as well, especially if you're burning food in your pan. So, it's still worth being aware of indoor air pollution from cooking in your oven or on the stovetop either way.

[Sarah] (20:44 - 20:46)
So, make sure you do have that rangehood.

[Anthony] (20:46 - 20:47)
Still a rangehood.

[Sarah] (20:48 - 20:55)
Well, you especially have to have that when you're closing up gaps and cracks in your home, because otherwise your house is going to smell of whatever you've cooked for days and days.

[Anthony] (20:55 - 20:56)
Yeah, correct. Yeah.

[Sarah] (20:56 - 21:05)
Yeah. So, we've talked about indoor air pollution a lot. Let's get to the outdoor air pollution.

What role do EVs play in reducing outdoor air pollution?

[Anthony] (21:05 - 21:51)
EVs play a huge role in this. It's actually one of the things that isn't aired enough is the harm from motor vehicle emissions, from tailpipe emissions from petrol or diesel vehicles is really significant. And some recent research out of Melbourne University indicated that we're probably losing about 11,000 lives per year just because of tailpipe emissions from petrol vehicles.

So if you had a fleet of vehicles across the country that were electrified, then those deaths theoretically would vanish and that extra morbidity, which includes about 60 to 70,000 extra cases of asthma a year as well, and almost 20,000 admissions to hospital for cardiac and respiratory illness in adults due to tailpipe emissions from motor vehicles that use petrol and diesel.

[Sarah] (21:51 - 22:25)
I remember reading an article, I think it was in the Guardian, saying that New South Wales taxpayers, it costs them annually about $4.8 billion in health costs associated with asthma, strokes, heart attacks, things associated with air pollution plus deaths. And I don't think we talk about the health savings. We talk about subsidies and it's costing us a lot of money to throw money at electric cars.

But on the counter side, there's these huge savings in health benefits that I just don't think we talk about at all.

[Anthony] (22:26 - 22:55)
They're invisible. It's like the pollution from tailpipes or from gas in a home. They're often invisible, so people don't think about them much.

But even asthma is estimated to have cost around $28 billion in 2015. And about $1.5 billion of that is direct healthcare related costs. So, it takes from the healthcare system, from our ability to sustainably keep Australians healthy, because we're spending our time treating things that we don't need to treat.

[Sarah] (22:55 - 23:18)
You're potentially treating things in children like behavioural things, or they're not learning difficulties, all the things associated with that as well, and the costs associated with that. Do you have any, either personal experience, or do you know any people who've actually noticed an improvement in those symptoms that you've described earlier once they removed gas from their home?

[Anthony] (23:18 - 24:16)
Yeah, I do. And interestingly, what I find in medicine, like in my practice, is that the only limit to the number of stories you hear is just how often you ask about it, and actually divine what people are experiencing in their own homes with gas. But literally two days ago, I had an elderly gentleman in a clinic who had a bit of a cough, and I asked him, does he use gas in his home?

And he said, no, but he used to be a smoker. So, he's got a bit of disease from smoking in the past. But his daughter, who was there helping him, was very, very interested and said, what do you mean?

Why is gas a problem? And I told her a bit more about it, and she said, well, that's it. I'm swapping out all my gas appliances because my daughter has had asthma her whole life.

I cook with gas at home. I always have. In the last few years, I've been cooking more because I've been at home a lot more, and my adult husband has been diagnosed with asthma in the last three years.

[Sarah]
No!

[Anthony]
That's just one example of many that I could offer you.

[Sarah] (24:19 - 24:26)
Stop it. Wow. And unless you ask people the question, we're just not going to know, are we?

[Anthony] (24:26 - 24:42)
No. Well, as a doctor, it's very frustrating to hear things like that because in aviation, as in medicine, you remove the cause. That's the only thing that'll stop it happening again.

So unfortunately, it will happen again and again until we remove gas from homes.

[Sarah] (24:42 - 24:50)
Yeah. Wow. That is sobering, but also good to talk about solutions.

Thank you so much, Anthony. That was great.

[Anthony] (24:50 - 24:53)
No problems. It's been great and enjoyable to come and chat to you.

[Sarah] (24:53 - 25:33)
So, three things to remember. Gas releases pollutants that affect both indoor and outdoor air. Children and people with asthma feel the impacts the most.

And finally, simple steps and electric alternatives like portable induction stoves and electric cars can help reduce exposure and improve air quality over time. 

That's it for this episode of The Good Energy Guide, brought to you by Ausgrid. You can find more episodes on Apple Podcasts, Spotify and YouTube.

And head to our website at goodenergy.ausgrid.com.au for practical tools and resources to help you make smarter energy choices.