How The Air Quality Index Can Be Used To Measure Bushfire Smoke

Hello. My name is Dr. Cameron Jones, and it is the 15th of January, 2020. And if you've been in Melbourne or Sydney or Queensland in the last couple of days and weeks, you've probably been exposed to all the smoke because of the devastation that the Australian 2019/20 bushfires and the havoc and destruction that has occurred across our country.

Some 186,000 square kilometers of vegetation has been burned. 5,900 buildings have been destroyed. 2,200 of those buildings have been people's homes. 29 people have been killed as a direct result of the fires, and we have lost approximately a billion animals and some of our native wildlife has been driven close to extinction and that is not to mention the extreme risks caused by exposure to all of the smoke. And this aspect of air quality is what I want to focus today on because it's really serious.

All you need to do is go outside Melbourne yesterday and today, and you will see people on bikes. They're wearing masks. We haven't seen this happening before, and I want to go over a lot of the metrics that are being used to explain this adverse air quality and how we go about measuring this. I want to also talk about a real-world example. I was called in yesterday to do an emergency indoor air quality inspection at a factory because the staff had in fact stopped work and the health and safety officers wanted to find out what was happening inside the factory and what the staff and also the office workers were being exposed to.

And this is a real problem because even the Australian Open today has been delayed. The air quality in Brighton, a suburb of inner-city Melbourne is right next to Caufield Racecourse, and races have actually been stopped due to the extreme risks posed by the smoke. I want to talk a little bit about the fact that this smoke is essentially a colloidal material and what I mean by a colloidal material is this is anything, a gas with suspended particles in it.

And today we're going to be focusing on air quality or the air quality index. And I'm going to be talking a lot about smoke and the fact that it is a colloid, it is a suspension, meaning that it is incredibly difficult to filter, and we're going to be going through some of the fundamental science underpinning smoke and colloids. And we're going to be talking about some of the microbiological aspects of smoke exposure as well. And of course, importantly, going into some fine detail about what the air quality index is.

And certainly, it's now the 15th of January, but I'm going to be discussing how we go about measuring air pollution. I'm going to show you some of the results of the testing that I've done in the last couple of days. And we're going to be focusing on that now. I'll just get this up on the screen.

So how do we go about measuring air pollution? Well, essentially air quality is evaluated using two types of metrics and they are called PM2.5 and PM10. The PM stands for particulate matter. And the numbers 2.5 and 10 represent the size of the particles in the air. And just consider these as different sized balls present in the smoke. And so the PM2.5 is the very fine balls or particles that are very easily inhaled and go deep within the lung. And this impacts on your thoracic system, whereas the PM2 particles, they're much larger and they will elicit a coughing reaction. And we're particularly concerned about the very fine particles because these are the ones that elicit the longterm inflammation type reactions, as opposed to the asthma type effects. They're all dangerous though. And this is what's present inside smoke.

So as I mentioned before, smoke is a colloid. It's called essentially a solid aerosol. It does not separate out on standing. Obviously we can see it scattering light. There've been some amazing photographs in urban areas showing the impact of the redness, the orange hues that are present when the sun sets later in the day. And it's very difficult to filter the smoke out, hence why it is so persistent and these sorts of filters, this is a P2 filter. I urge anyone who is highly concerned or sensitive to smoke to be going beyond the P2 filter and be going up to a P3 filter.

And really the standard way that we communicate risk around air quality and smoke exposure is this air quality index. Now the range essentially doesn't necessarily have units, but you need to think of this in terms of number terms with it goes from zero to 500. Now these particles or the smoke particles have a size and a mass. And the instruments that we use to quantify the amount of haze or smoke or pollution in the air usually measures one or both of these properties. That is the number of particles in the air or their weight.

Now, in my work that we do pretty much every day in home inspections when we're measuring for bioaerosol or the amount of microbes in the air, we use different types of instruments, and these are the same instruments that we're now using for smoke detection and quantification or measurement. So the first instrument that I'm going to be showing you some videos of how these work and you can see for yourself what they're actually measuring in the air.

The first measure is something called the cumulative particle size distribution and this is a sizing instrument. And just think of this as just counting up the number of particles per unit time. Now the second type of instrument will measure the mass, and that will report the measurements in micrograms per cubic meters of air. And that's just a different side of the same coin. And so because particles have size and mass, so you can describe the dispersion or the smoke colloid using total numbers or by weight. And then the air quality index, which is used to determine the health effects or impacts, and for people to make decisions such as delaying the Australian Open or in the factory example, encouraging a very valid reason for staff not to be working in that particular facility at that particular time.

And the important thing to note in all of these health metrics is a value beyond 101 is the level that violates the National Health Standard for exposure to particulate matter in the air. And so I'm now going to play a video to you, which I shot the other night and it's pretty self-explanatory. It only goes for a minute or two, and it puts in context not only the problem but how we go about measuring it.

I'm in downtown Melbourne. Just returned from the gym. And the impact of the Australian bushfires is really quite phenomenal. This is inner-city Melbourne, and you can see that the smoke is so dense. I'm going to use a particle counter in a minute to show you what the particulate matter counts are in this suburban street. So I've got a particle counter in front of me and I'm standing in my front garden and you can see that I'm using this thing called an AeroTrak particle counter. And I'm going to start recording now, and you're going to see that it's going to start sampling the air.

And you can see a few things here that I want to draw your attention to. On the left-hand side, there is a range of numbers showing 0.3 0.5 1, 3, 5, and 10 microns. Think of these as bins. Now on the right-hand side, there's another column which is counting in real-time. And you can see that the fine particulate matter is just increasing at a huge rate. And so when we talk about particulate matter, we're talking about something called PM2.5 usually. And usually, that is the aggregate of the 0.3 0.5 and 1 and 3 micron-sized particles. And that PM10 is usually comprised of the 5 and 10 micron-sized particles. And as you can see, the air quality is horrific.

This is a residential street. Imagine what all of this particulate matter is doing close to ground zero. And unfortunately in Australia and wherever there are forest fires, ground zero is really the worst place to be. But all of this smoke ends up blanketing the city and in large parts of Australia that is suffering the impact of forest fires, this smoke we're getting used to it and it's in our cities and it comes into our homes. And this has got a huge impact on respiratory health. So be aware that this is what's in the air, the levels, the numbers are massive.

Okay, 18.6 million hectares burnt. All of that smoke's got to go somewhere. And as you can see in that video, that was shot after 1:00 AM on the 14th of January, 2020 in a residential street in Melbourne, the levels of particulate matter in the 2.5-micron size range, the fine particles are really horrendous.

Now I want to move on to an urgent phone call, which I received, which was from the person responsible for occupational health and safety at a large factory here in Melbourne. They're very concerned yesterday because a lot of their staff had gone off work because of their concerns about the amount of smoke. And again, this is a very interesting workplace issue because it's nothing that the facility was doing wrong. And in fact, the data showed that they were doing everything right from an occupational health and safety perspective, but that the phenomena of these bushfires and the fact that the smoke really gets in everywhere mean that some workplaces are just unsafe and hazardous due to the physics of dispersion of these colloidal smoke materials. So that's the background that I'm going to give you for the next short video.

Obviously I'm not going to reveal any details about the location of this, but all the testing was done yesterday on the 14th at approximately 3:00 PM. Before we move that, I want to go into the movie and play that.

Now I'm just finishing an indoor air quality inspection. And I can't tell you where I'm at, but I was called in to do a smoke analysis on this factory behind me because of the forest fires that we're having here in Australia. And the reason I'm here is because the staff who are working in this factory are very concerned about the levels of smoke inside the factory and also inside some of the offices. So I took out my particle size analyzers. It came down to this factory and I've been working the last couple of hours. And I'm going to show you the graphs showing you exactly what smoke does to workers. Anyway, talk to you soon.

Okay. You can see in that short video, the context of the work. So basically what happened yesterday is that we went in with a couple of devices to measure the amount of smoke present in the factory in different locations. And you can immediately see that the air quality inside was rated at severe. This first instrument is measuring the mass of particles. The next instrument is the one that I use daily. This is measuring the cumulative size, and this puts this into different size fractions. And you can immediately see in the very fine ultra-fine 0.3-micron size range that we've got millions of particles present. And then of course we compared the outdoor levels to the indoor levels and office areas as well.

Now, how do we make sense of this? Well, I mentioned before that the air quality index is a numerical rating scale between zero and 500. It is a six threshold or a six-point scale, and it assesses your air quality from good to hazardous. And in the last picture, we were able to see that everything was over 200 in the very unhealthy or the purple sized band. And certainly for the Australian Open to postpone play, for races to be stopped, for workers on construction sites to be encouraged to not necessarily work outdoors.

Things are pretty extreme in urban areas in the Southeast of Australia. We have some of the worst air quality in the world due to these bushfires. And so if we look at this air quality index and we look at the health messages around it, you can see that even at the low level, at 51 to 100, sensitive people are encouraged to reduce and not exert themselves too strenuously. And you can then see that as we move into the purple area where for example, most of us in downtown Melbourne is between the 150 and 300 range, it means that again, the general public should not exert themselves too strenuously, sensitive people should avoid physical activity outdoors. And really these are the predominant health messages. And these are really, really fundamental to protecting yourself. When these natural disasters happen, it's not sufficient to just look outside and say, it's smoky; you do need to protect yourself, especially if you've got any underlying respiratory issues.

Now you're probably all wondering what were the results from that particular factory? So for that, I'm showing a graph here from the outdoor area. For those of you who are listening to this as a podcast, essentially what we did was we went into some key areas within the factory. We compared the levels of PM2.5 and PM10. That is the fine and the core size fractions outside. And then we measured the levels inside and in some of the offices, because a lot of the people who are working in the offices said, "Look, it seems okay in here, but we seem to be getting some irritation, eye irritation. We're not really smelling anything, but it feels different to the way it normally does without the smoke."

And you can see immediately when we graph the results that the offices certainly were better, but all areas of the factory were just as bad as outdoors. So this really emphasizes the fact that smoke tends to get in everywhere. Certainly when it is present at such massive levels, due to the extreme bushfire events that we have been experiencing. And you can certainly see that I have shown on the graph on the bar graph, the four of the levels of the air quality matrix or threshold for interpreting risk. And you can see that most of the areas of the factory where work is actually being done, as opposed to office work, they are all above recommended thresholds. Meaning that that workplace is unsafe.

Now, what else do I need to tell you about? Well, there is a marvelous website with the domain above called waqi.info, which allows you to go across the globe and also focusing on Australia and look at the air quality, because a lot of sensors are in place throughout the country, which gives us real-time readings about air quality without having to resort to companies like mine, to actually come out on-site and do some fine data collection.

And if we look at yesterday evening, we were able to see that the levels of particulate matter that I picked up on the sensors were definitely back into the unhealthy range. I've just checked a few minutes ago. And as I said, suburbs like Brighton are certainly in the extremely unhealthy and hazardous range as we speak.

Now, what are some recommendations for protecting yourself? Well, obviously we can continue with masks. Masks are a great idea. P2 masks at minimum. They need to fit, flush with the face. Anyone who has facial hair, that's going to be a problem. If you wear glasses, make sure that you fit it as tightly as possible, minimize exercise and minimize being outdoors. Certainly the roads were definitely less busy yesterday. I'm not sure what they're like today. Choose less strenuous exercise and outdoor work, avoid exercising outdoors. It's probably not a good idea to be running around in our parks and gardens with all this smoke being present. Closing windows at home and in your offices.

There are a lot of tips that are present on a lot of the public health websites. I won't reiterate that material here, but closing windows is a good idea. You should operate your air conditioning both in your home and in your vehicle or car on recirculate mode, otherwise, you'll be introducing a lot of this smoke straight into the cabin of the car. That's not a good idea. And of course, be aware of any asthma risk and follow any asthma management plan and have preventative medication as required by your healthcare practitioner.

So they're the key recommendations. They are all commonsensical. Follow them, and really that's all we can do because we'll just have to wait to a lot of this particulate matter disperses.

Now we also need to touch very briefly on something that has emerging in the research literature, that the smoke also contains other materials apart from burnt vegetation, trees, and that sort of thing. And it definitely contains quite high levels of biological matter. And this is a new field called Pyroaerobiology, and the research scientist who really has pioneered this work is in the Department of Natural Resources and Society at the University of Idaho. And I urge you to download this paper and have a good read about it because it is talking about or predates these massive forest fires that we're experiencing here in Australia. And there certainly fire events of high magnitude occurring in other parts of the world as well.

And this issue of the impact of the microbiology also being present and dispersed into the atmosphere means that the smoke has an additional risk. And certainly, for any of those clients and patients that consider themselves susceptible to mould illness, I suspect that the era of Pyroaerobiology will mean that exposure to smoke at high levels means that you're also being exposed to these unwanted microbes and cell wall fragments at a micron and sub-micron size.

And I really just want to conclude this short presentation by reading from the abstract in her paper, which states that, "The potential for smoke to aerosolize and transport viable microbes is a virtually blank piece of the microbial biogeography puzzle with far-reaching implications." And her research is showing that there is a huge amount of microbial matter, which is dispersed in these colloids. So really we have considered smoke and certainly, the literature considers smoke as a colloid, but her research validates the fact that it should really be considered as a bio colloid and really that is a very interesting area of fundamental science.

My name's Dr. Cameron Jones, this presentation on air quality, I hope has provided you some background on the statistics underlying the different thresholds used to describe smoke. And next week we will be back with regular live streams back to a lot of microbiology next week. In any case, we'll be putting this up on to YouTube and also out to our podcast on themouldshow.com. In any case, have a great week, protect yourself as best you can, use masks as necessary, minimize your time spent outdoors and let's all hope that the fires dissipate ASAP without any further loss of life. Anyway, bye for now.