Bushfire smoke is bad for your eyes, too. Here’s how you can protect them



When the hazardous particles found in bushfire smoke come into contact with our eyes, this can cause inflammation.
From shutterstock.com

Katrina Schmid, Queensland University of Technology and Isabelle Jalbert, UNSW

As we continue to contend with smoke haze in various parts of the country, many Australians may find themselves with watery, burning, irritated or red eyes.

Data from countries with consistently poor air quality suggest there could also be a risk of longer term effects to our eyes, particularly with prolonged exposure to bushfire smoke.

Although P2/N95 masks can protect us from inhaling harmful particles, unfortunately they can’t protect our eyes.

But there are certain things you can do to minimise irritation and the risk of any longer term effects.




Read more:
We know bushfire smoke affects our health, but the long-term consequences are hazy


Irritation in the short term

The eye’s surface is continuously exposed to the environment, except when our eyes are shut when we sleep.

Bushfire smoke contains dust, fumes (such as carbon monoxide and nitrogen oxides), and tiny particles called PM10 and PM2.5.

When the smoke comes into contact with our eyes, the fumes and small particles dissolve into our tears and coat the eye’s surface. In some people, this can trigger inflammation, and therefore irritation.




Read more:
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The presence of a marker called matrix metalloproteinase-9, or MMP-9, indicates the eye is inflamed.

During periods of poor air quality from bushfires in the United States, MMP-9 was present in the eyes of more people than it ordinarily would be.

Longer term risks

We know very little about how pollution from bushfire smoke might affect our eyes over the longer term, or what damage repeated or chronic exposure might do.

But we do know people who live in areas with high levels of air pollution, such as China, are three to four times more likely to develop dry eye.

Dry eye is a condition where a person doesn’t have enough tears or they are of such poor quality they don’t lubricate and nourish the eye. We need high quality tears to maintain the health of the front surface of the eye and provide clear vision.

For people who already have dry eyes – often older people – poor air quality may increase the damage. The smoke and pollution may cause intense stinging and a feeling of grittiness to the point they can barely open their eyes.

Avoid rubbing your eyes, as this could make the irritation worse.
From shutterstock.com

While dry eye is a result of damage to the surface of the eyes, it’s also possible pollutants entering the blood stream after we breathe them in could affect the blood supply to the eye. This in turn could damage the fine vessels within the eye itself.

Research has suggested high levels of air pollution in Taiwan may increase the risk of age-related macular degeneration, which could be an example of this.

We need more research into the long-term effects on our eyes of prolonged poor air quality, particularly from bushfire smoke. But what we do know suggests it’s possible bushfire smoke could be causing subtle damage to the eyes, even in people without any symptoms.




Read more:
Even for an air pollution historian like me, these past weeks have been a shock


What can you do to protect your eyes from the smoke?

  • the best option is to avoid going outside when air quality is at is worst, where possible
  • wearing sunglasses or glasses when outside if you need them might stop some of the dust carried in the wind from contacting the eye’s surface (but it won’t stop the tiny particles getting in)
  • avoid wearing contact lenses if possible.

Some tips if your eyes are irritated

  • flush your eyes as often as you can, with over-the-counter lubricant eye drops if you have some on hand. If not, use sterile saline solution or clean bottled water
  • if your eyes are itchy, flush them and then place a cool face washer over your closed lids
  • don’t rub your eyes, as this could make the irritation worse.

If your eyes are red and sore and these steps don’t help, it’s best to see an eye care professional.




Read more:
From face masks to air purifiers: what actually works to protect us from bushfire smoke?


The Conversation


Katrina Schmid, Associate Professor, Queensland University of Technology and Isabelle Jalbert, Associate Professor, School of Optometry and Vision Science, UNSW Sydney, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia: Bushfire News Update


Bushfire smoke is everywhere in our cities. Here’s exactly what you are inhaling


Smoke from recent bushfires has shrouded major Australian cities.
AAP/Erik Anderson

Gabriel da Silva, University of Melbourne

As bushfire smoke blankets large parts of Australia, it’s time to examine what this complex chemical mixture is made of, to better understand what it’s doing to both our bodies and the planet.

I research the chemical processes that create pollutants in flames, and what happens when they are released into the air we breathe.

Bushfires are not the only source of smoke we are exposed to in our everyday lives. We breathe smoke from cigarettes, wood-fired heaters, coal-fired power stations and vehicles.

But smoke stemming from the bushfires is accumulating over cities in concentrations rarely seen before in Australia, badly affecting cities including Sydney, Melbourne and Canberra. This poses risks to public health and the environment. Read on to find out exactly what you’re breathing in.

A smoke-filled Canberra street on January 5 this year.
Lukas Coch/AAP

It’s largely water

First, there is a lot of water in bushfire smoke. When fire rips through a forest it burns off the water held in the trees, sending rolling clouds of steam up into the atmosphere.

Water might seem harmless, but it actually enables bushfires to form their own weather. Water vapour condenses on smoke particles and forms huge pyrocumulonimbus clouds. We saw these storms in the current fire crisis. They can complicate firefighting efforts by producing wind and lightning strikes but unfortunately rarely bring rain.




Read more:
Even for an air pollution historian like me, these past weeks have been a shock


These clouds also inject smoke high into the atmosphere from where it can circle the globe. We recently saw this when smoke from bushfires in Australia’s south-east drifted to New Zealand and then on to South America. Smoke lofted into the stratosphere influences the climate by blocking the movement of light and heat, and can even interfere with chemistry in the ozone layer.

A man wears a face mask to protect himself from bushfire smoke in Melbourne on Tuesday this week.
AAP/Erik Anderson

The climate effect

Smoke also contains gases, most notably carbon monoxide (CO) and carbon dioxide (CO₂). Carbon dioxide is the end-product of combustion and is the most significant contributor to man-made global warming.

Forests sequester massive amounts of carbon as wood and other organic matter and much of this is released back into the atmosphere as carbon dioxide when burned.

Within about a year, these molecules could be anywhere in Earth’s atmosphere. CO₂ is so long-lived that many of these same molecules will remain circling the globe for hundreds of years.




Read more:
We know bushfire smoke affects our health, but the long-term consequences are hazy


This bushfire season, more than 10 million hectares of land has already burned. Estimates based on satellite data put the subsequent CO₂ release at 400 million tonnes. This is close to Australia’s total annual greenhouse gas emissions of around 500 million tonnes of CO₂ equivalent.

Our planet’s climate emergency is already making Australia hotter and drier, with more frequent extreme weather events. The ensuing fires are in turn releasing carbon back into the atmosphere, forming a dangerous positive feedback loop.

A satellite image showing burned land and thick smoke over Kangaroo Island on January 9.
NASA Earth Observatory

The poisonous sibling

Whereas CO₂ presents a long-term threat to us all, its poisonous sibling carbon monoxide (CO) is a more immediate concern to those directly exposed to smoke. Carbon monoxide forms when combustion is interrupted on its way to make carbon dioxide.

At the high concentrations found in smoke, carbon monoxide can be deadly. It binds strongly to our haemoglobin – the molecule in red blood cells that carries oxygen around the body. At around 100 parts per million in air it can starve the human body of oxygen, asphyxiating its victims.

Carbon monoxide poisoning through smoke inhalation is a direct concern to firefighters and those sheltering from flames. Those fighting bushfires often work long shifts, sometimes over several weeks, with face masks that offer limited protection.


Wes Mountain/The Conversation, CC BY-ND

But that’s not all

In addition to these two gases, smoke contains trace levels of many other pollutants such as sulfur dioxide (SO₂) and nitrogen dioxide (NO₂). In a bushfire, these are produced through the burning of sulfur and nitrogen in plants.

(These gases are also produced through burning fossil fuels. Over eons, ancient trees fossilise into oil and coal but retain some sulfur and nitrogen).




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Both SO₂ and NO₂ irritate our respiratory system. Atmospheric SO₂ is also problematic because over time it gets converted in air into sulfuric acid, forming acid rain. NO₂, on the other hand, breaks down in sunlight causing harmful ground-level ozone to form.

We are still learning about other dangerous trace gases in smoke. For instance, in the last decade we have come to realise that highly toxic isocyanic acid from smoke can be present in urban air at concentrations approaching those which are known to impact our health. Unfortunately, little research is available for Australian conditions.

Don’t forget the tiny particles

The final component of smoke we need to consider are the solid particles, or particulate matter (PM). This is both soot that builds up during combustion, and ash that breaks down from the remnants of burnt fuel.

What we see following a bushfire are mostly the larger particles, which reduce visibility and settle on cars and buildings. But the most dangerous component to our health are microscopic particles around one millionth of a metre in size.

These particles can penetrate deep into our lungs and make their way into our bloodstream, potentially impacting almost every bodily system.

Moreover, because of their size they are more likely to stay aloft in air and be transported away from their source.

Particles smaller than 2.5 micrometres, known as PM2.5, settled on Canberra in recent weeks – a problem so severe on some days the city could lay claim to having the most polluted air in the world.

Tourists take selfies against a smoke-filled Sydney Harbour this month.
STEVEN SAPHORE/AAP

Be prepared

Bushfire smoke is a complex chemical mixture that can affect humans in many ways. As fires become increasingly common across our continent, we must become more familiar with what we are breathing in.

Australia’s unique vulnerability to climate change, as has been evident this bushfire season, means we should also lead the world in reducing greenhouse gas emissions.

At the same time, Australians need to adapt. This means equipping our buildings with sensors and purifiers to respond to air pollution and educating the public on how to stay safe during an air quality emergency. It’s clear we must prepare for many smoke-filled summers to come.




Read more:
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The Conversation


Gabriel da Silva, Senior Lecturer in Chemical Engineering, University of Melbourne

This article is republished from The Conversation under a Creative Commons license. Read the original article.

I’m struggling to breathe with all the bushfire smoke – could I have undiagnosed asthma?


Christine Jenkins, George Institute for Global Health

As bushfire smoke continues to pollute the air of large parts of Australia’s eastern states, some people have experienced throat irritation, coughing and breathing difficulties.

Health authorities have also warned more severe symptoms such as chest tightness and wheezing may emerge in people who have underlying asthma and in people who haven’t yet been diagnosed.

Wheezing is a high-pitched whistling sound when you breathe, caused by muscle spasm or inflammation in narrowed airways.




Read more:
Bushfire smoke is everywhere in our cities. Here’s exactly what you are inhaling


Normal response to bushfire smoke

Respiratory symptoms can occur in otherwise healthy people in response to bushfire air pollution. This is due to large and small particulates in fire smoke irritating the the thin lining of the respiratory tract, called the mucous membrane.

These particles tend to cause increased secretions, inflammation and irritation of the eyes nose and throat, even in people who have no history of lung disease.

Why it’s important to know your asthma profile

Asthma is an inflammatory disease which causes narrowing of the airways. Symptoms and flare-ups or attacks can occur after exposure to a wide range of triggers.

If the airway inflammation isn’t treated, it can progress to more significant and permanent airway narrowing that results in persistent breathlessness and loss of lung function.

If left untreated, asthma can cause permanent damage.
Fizkes/Shutterstock

If you have asthma, it’s most important to know the severity, how to control it, and how to identify and promptly treat an attack.

What might signal undiagnosed asthma?

People with asthma can experience severe attacks or flare-ups when exposed to bushfire smoke, or persistent respiratory symptoms that don’t settle promptly after their smoke exposure ends.

Symptoms that suggest the possibility of asthma include chest tightness and wheezing in response to exposure to irritants such as smoke, dusts, aerosol sprays and fumes, or in response to allergic triggers such as pollens, cat and dog fur, house dust, and mouldy atmospheres.

Asthma can also manifest as a cough.

Many people with asthma have a history of hayfever, often provoked by pollens, house dust, cat and dog fur, and moulds.




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People with a family history of asthma are at greater risk of developing the disease, as are those with a history of wheezing illness in childhood caused by viral respiratory infections. In fact, viruses that cause the common cold are frequent triggers of asthma attacks.

Some people with asthma may experience symptoms predominantly when they exercise. In such cases, chest tightness and wheezing typically occurs while exercising but often intensifies over a few minutes after stopping.

What to do if you’re unsure

If you experience symptoms of asthma from the bushfire smoke, see your GP.

To assess whether you have asthma, your doctor will undertake a breathing assessment called called a spirometry test. This requires you to blow into a mouthpiece to assess how much air you can blow out and how quickly you can expel the air.

Here’s how a spirometry test works. National Asthma Council Australia

The doctor will also determine whether there is airway narrowing which improves after taking a bronchodilator – a reliever medication such as Ventolin.

It’s not OK to just take asthma medicines, gain some benefit and conclude you have the condition. Many respiratory symptoms can easily be mistaken for asthma, particularly when they occur in association with viral respiratory infection.

How is asthma treated?

Many people believe their asthma is being treated if they use their blue reliever inhaler as needed.

Asthma relievers aren’t meant for daily use.
Image Point Fr/Shutterstock

But relievers don’t address the underlying airway inflammation, even though they relieve the symptoms. They should never be used as a daily medication for asthma.

Asthma treatment requires an anti-inflammatory medication, usually an inhaled corticosteroid taken regularly. These medications control the underlying inflammatory process and prevent symptoms and attacks.

Anti-inflammatory treatments are effective in maintaining asthma control day by day so that even with smoke and air pollution exposure, symptoms and attacks are less likely to occur.




Read more:
We know bushfire smoke affects our health, but the long-term consequences are hazy


People with asthma should have a written action plan which identifies symptoms that typically occur during asthma flare-ups and enables patients to increase their medications appropriately.

Finally, because asthma is a chronic inflammatory condition it requires monitoring and regular review. In these reviews, your doctor will check your lung function and ensure you’re taking the right medication and that your action plan is up to date.The Conversation

Christine Jenkins, Professor, Respiratory Medicine, UNSW Sydney and Uni of Sydney; Head, Respiratory Group, George Institute for Global Health

This article is republished from The Conversation under a Creative Commons license. Read the original article.

What employers need to know: the legal risk of asking staff to work in smokey air


Elizabeth Shi, RMIT University

Amid thick bushfire smoke in cities including Canberra and Melbourne, employers need to consider their legal obligations.

Some have directed their workers not to turn up in order to avoid to occupational health and safety risks. Among them is the Commonwealth department of home affairs which last week asked most of its staff to stay away from its Canberra headquarters for 48 hours.

Other employers want to know where they stand.



Each state and territory has its own occupational health and safety laws.
However most line up with the so-called Model Act, a federal act of parliament intended to harmonise state laws.

Under section 17 it imposes on employers a duty to, so far as is reasonably practicable, ensure health and safety by eliminating or minimising risks.

This employer’s duty applies not only to its employees, but also to other types of workers including independent contractors.

Meaning of ‘reasonably practical”

Under the section 18 of the Model Act, “reasonably practicable” means

that which is, or was at a particular time, reasonably able to be done in relation to ensuring health and safety, taking into account and weighing up all relevant matters

By themselves, these words aren’t much of a guide, so the Act includes examples of “relevant matters”, among them:

  • the likelihood of a hazard or risk occurring

  • the degree of harm that might result

  • what the employer knows or ought reasonably know about the hazard or risk, and ways of eliminating or minimising hazard or risk

  • the availability and suitability of ways to eliminate or reduce hazard or risk

  • the cost associated with available ways of eliminating or minimising the risk, including whether the cost is grossly disproportionate to the risk

Meaning of ‘likelihood’

Employers should make themselves aware of the risk of an air quality hazard.
This can be achieved by checking the most up to date air quality index in the location on an environment protection authority website:

NSW

Victoria

Queensland

South Australia

Western Australia

Tasmania

Northern Territory

Australian Capital Territory

Workers who work outdoors are more likely to be subject to harmful effects of bushfire smoke than indoor workers.

They are more likely to experience irritation to their airways, nose and eyes.

They might also experience low visibility which might make their work more dangerous.

The machines they operate could also be impacted by the smoke and dust in a way which would make operating them more dangerous.

Special measures should be taken to protect workers who work outdoors, such as providing them with face masks or rescheduling their work.

Smoke emissions from the Australian bushfires from 1 December 2019 to 4 January 2020.

Meaning of ‘degree of harm’

Asthma suffers might be at greater risk.

It is certainly arguable the likelihood of harm for indoor workers is much lower, especially if the air quality in their workplace is the same or even better than the air quality in their homes.

Employers should have up-to-date information about the health of their workers, especially those workers who have pre-existing conditions that might predispose them to harm from smoke.

Among these would be workers who have asthma or other respiratory disorders.

Special steps should be taken to protect them, taking into account their pre-existing conditions.

Meaning of ‘reasonably ought to know’

Employers should be checking up-to-date information on an environment protection authority website and on the website of Safe Work Australia which is the Commonwealth regulator for occupational health and safety laws.

It’s very likely law enforcers will presume the information on these websites constitute information the employer ought to have known in determining the appropriate action to take.

For example, it would be difficult for an employer to argue they didn’t know P2 rated face masks should be provided to workers when the Safe Work Australia website specifically mentions them as an appropriate way of eliminating or reducing air quality hazards.

Meaning of ‘availability of ways to reduce risk’

Safe Work Australia directs employers to have in place measures to manage the risks to health and safety of working outdoors when air quality is reduced, including:

  • working indoors (where possible)

  • rescheduling outdoor work until conditions improve

  • ensuring buildings and equipment are functioning correctly and have not been affected by dust or debris

  • cleaning dust and debris off outdoor surfaces

  • providing personal protective equipment such as eye protection and correctly fitted P2-rated face masks.

Meaning of ‘cost of minimising hazard’

The cost of elimination or minimising hazard will be higher for some measures than others.

For example, it might cost more to direct workers to stay home than to provide face masks.




Read more:
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These costs need to be weighed up against the likelihood and degree of potential harm.

If the likelihood and degree of harm is high, it’s unlikely law enforcers will be particularly sympathetic to arguments about cost.The Conversation

Elizabeth Shi, Senior Lecturer, Graduate School of Business and Law, RMIT University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Australia: Bushfire Crisis Update


We know bushfire smoke affects our health, but the long-term consequences are hazy


Brian Oliver, University of Technology Sydney

In previous years, Australians might have been exposed to bushfire smoke for a few days, or even a week. But this bushfire season is extreme in every respect. Smoke haze has now regularly featured in Australian weather reports for several weeks, stretching across months in some areas.

What we considered to be short-term exposure we must now call medium-term exposure.

Given this is a new phenomenon, we don’t know for sure what prolonged exposure to bushfire smoke could mean for future health. But here’s what air pollution and health data can tell us about the sorts of harms we might be looking at.




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Short-term effects

We know poor air quality is having immediate effects, from irritated eyes and throats, to more serious incidents requiring hospital admission – particularly for people with existing respiratory and heart conditions.

After the smoke haze hit Melbourne on Monday, Ambulance Victoria recorded a 51% increase in calls for breathing difficulties.

This aligns with Australian and international research on the acute effects of exposure to bushfire smoke.

But the long-term effects aren’t so clear.

Video credit: Australian Academy of Science.

Long-term effects: what we know

When considering the long-term health consequences of air pollution, we draw on data from heavily polluted regions, typically in Africa, or Asia, where people are exposed to high levels of airborne pollution for years.

It’s no surprise long-term exposure to air pollution negatively affects health over their lifetime. It’s associated with an increased risk of several cancers, and chronic health conditions like respiratory and heart disease.

The World Health Organisation estimates ambient air pollution contributes to 4.2 million premature deaths globally per year.

A recent study in China reported long-term exposure to a high concentration of ultrafine particles called PM2.5 (which we find in bushfire smoke) is linked to an increased risk of stroke.




Read more:
How does poor air quality from bushfire smoke affect our health?


We also know the dose of exposure is important. So the worse the pollution, the greater the the health effects.

It’s likely some of these long-term effects will occur in Australia if prolonged bushfires become an annual event.

Experimental studies

Observational studies, like the Chinese one mentioned above, demonstrate the long-term health effects of long-term exposure to air pollution. But we don’t really have any studies like this following populations which have experienced short- or medium-term exposure.

To explore the health risks of more limited exposure, we can look to experimental data from cell and animal models.

These studies follow the models for days (short-term) or weeks (medium-term). They show exposure to any type of airborne pollution – from traffic, bushfires, wood or coal smoke – is detrimental for health.

The results show increased inflammation in the body, and depending on the model, increased incidence of respiratory or heart disease.

What about bushfire smoke?

We don’t have a lot of experimental data on the effects of bushfire smoke specifically, apart from a few studies on cells in the lab.

In my lab we’ve found the short-term in-vitro effects of bushfire smoke are comparable to the smoke from cigarettes. This does not however mean the long-term heath effects would be the same.




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If we think about what’s burning during a bushfire – grass, leaves, twigs, bushes and trees – it’s also reasonable to draw on experimental data from wood smoke.

Wood smoke contains at least 200 different chemicals; some of them possible carcinogens.

In one small study, ten volunteers were exposed to wood smoke for four 15 minute periods over two hours. Afterwards, participants experienced increased neutrophils, a type of aggressive white blood cell, in both their lungs and circulation. The concentration of particulate matter in the wood smoke was lower than the levels we’ve seen in Sydney.

Different parts of the world will experience different types of air pollution.
From shutterstock.com

These short term studies show bushfire smoke is toxic, and it’s this toxicity which is likely to cause long-term effects.

One review found lifelong exposure to wood smoke, for example from indoor heaters, is associated with a 20% increased risk of developing lung cancer. Though it’s important to remember this is long-term exposure; the risks associated with medium-term exposure are not yet known.

How can we apply these findings?

Taking data from one type of airborne pollution and applying it to different pollutants – for example comparing the smoke from only one type of wood to bushfire pollution – is complex. The chemical make up is likely to differ between pollutants, so we need to be cautious extrapolating results.

We also need to be wary about how we translate results from cell and animal studies to humans. Different people are likely to respond to bushfire smoke differently. Our genetic make up is important here.

And with variable factors like at what age the exposure starts, how long it lasts, and other factors we’re exposed to during our lives (which don’t exist in a petri dish), it’s difficult to ascertain how many people will be at risk, and who in particular.

Looking past the haze

The human body actually has a remarkable capacity to cope with air pollution. It appears our genes help protect us from some of the toxic effects of smoke inhalation.

But this doesn’t mean we’re immune to the effect of bushfire smoke; just that we can tolerate a certain amount.

So would a once in a lifetime medium-term exposure have a chronic effect? At the moment there’s no way of answering this.




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But if, as many people fear, this medium term exposure becomes a regular event, it could cross into the long-term exposure we see in some countries, where people are exposed to poor air quality for most of the year. In this scenario, there’s clear evidence we’ll be at higher risk of disease and premature death.

For now, we desperately need studies to help us understand the effects of medium-term exposure to bushfire smoke.The Conversation

Brian Oliver, Research Leader in Respiratory cellular and molecular biology at the Woolcock Institute of Medical Research and Professor, Faculty of Science, University of Technology Sydney

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Our buildings aren’t made to keep out bushfire smoke. Here’s what you can do



On many days Canberra has the worst air quality of any major international city. Even in the best buildings it’s not good.
NARENDRA SHRESTHA/EPA

Geoff Hanmer, UNSW

In early December 2019, a Sheffield Shield cricket match between NSW and Queensland was played in bushfire smoke so thick that the ball was at times invisible to the spectators.

Since then, the rest of us have become far more aware of the hazards of bushfire smoke, and authorities have become more active in reminding us how dangerous it can be, especially during exercise. A standard piece of advice is to “spend more time indoors”.

But does it work?

Up until this year, with bushfire smoke lasting only a few days, it was good advice, especially for buildings that rely on recirculated and filtered mechanical ventilation complying with Australian Standard 1668 Part 2.

These buildings include shopping malls, cinemas, hospitals, larger offices and some of the buildings in some universities.

It’s fine in cinemas, for a while…

Unfortunately, if smoke is particularly thick or goes on for more than a few days, these systems get overwhelmed, which is why smoke detectors in many commercial and institutional buildings have been setting off fire alarms and why the National Gallery of Australia in Canberra was closed on Sunday and Monday.

Most houses or apartments are designed to be “naturally ventilated” under the National Construction Code, which means every habitable room has an openable window or a vent.

Closing the windows, vents and doors will reduce the “air change rate”, which is the number of times an hour the air in the room is replaced by outside air.

Less fine in homes

Regrettably, unless there is no wind, CSIRO research suggests most Australian houses are quite leaky by international standards, mainly because of leaky windows and doors.

Wall ventilator.
Source: GIYGreenItYourself

Houses and apartments built before 1970 are the worst. Many have fixed ventilators just below the ceiling level, a hangover from regulations designed to ensure gas lighting did not cause asphyxiation.

These ventilators are now unnecessary and can be safely blocked off.

In normal times some leakage is not a bad thing, as it offers protection against internal air pollution from volatile organic compounds in furniture and building materials and cooking, smoking and heating.

But these are not normal times.

The length and severity of bushfire smoke appears to be unprecedented.

With bushfire smoke persisting for days or weeks, the standard advice to be “indoors” is less effective. While houses and apartments might be useful for keeping smoke out for a few days or so, they become less effective over time, depending on how leaky they are.

Take care

Before embarking on a campaign to seal leaks with draft stripping and duct tape, please ensure your that your range hood is vented directly to outside (preferably with an automatic flap) that if you smoke you do it outside, and that your furniture and fabrics are low in volatile organic compounds, which arechemicals that release vapor at room temperature.

If your house is sealed up, do not use a gas cooker without an externally vented range hood or use an unflued gas heater at any time.

Ensure your vacuum cleaner has a HEPA (high-efficiency particulate air) filter.

Remember duct tape or masking tape is likely to be very difficult to remove if you leave it on for more than a few days and may damage painted surfaces.

Air conditioners aren’t much help

Even if your house is well sealed, it’s likely the air in it will become similar in quality to the air outside over a period of several days. While the air change rate in your house might be low, it will not be zero.

A recirculating air conditioner, such as a split system, will make you cooler but most domestic air conditioning filters are not capable of removing the very small particles in bushfire smoke – the ones that most make it dangerous.

Evaporative air conditioners or window mounted air conditioners that draw air in from outside will actually make indoor conditions worse.

Some recirculating air purifier systems will remove bushfire smoke, but they can be expensive to buy and run.

Air purifiers can help, but they’re expensive

To be effective against bushfire smoke, the air purifier needs to be fitted with a HEPA filter.

The performance of many purifiers is less than stellar, but a CHOICE survey published just before Christmas is a useful starting point.

CHOICE is preparing a bigger test of more models which it will publish in March 2020.

It brought forward the test of six of them because of the fires.




Read more:
From face masks to air purifiers: what actually works to protect us from bushfire smoke?


All six remove bushfire smoke particles with various degrees of efficiency, but their coverage area is limited. The Blueair 205 performed the best.

For people in an at-risk group, the use of an air purifier in a sealed-up house or apartment should help.

The only certain solution for someone suffering from smoke or concerned about its long-term impacts is to go to a building that has a recirculating HEPA filtered air conditioning system or move to a location where the air quality is better.The Conversation

Geoff Hanmer, Adjunct Lecturer in Architecture, UNSW

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Pregnant women should take extra care to minimise their exposure to bushfire smoke



Pregnant women should try to stay inside when the air pollution is high.
From shutterstock.com

Sarah Robertson, University of Adelaide and Louise Hull, University of Adelaide

Smoke haze from Australia’s catastrophic bushfires is continuing to affect many parts of the country.

Although there’s no safe level of air pollution, the health hazards tend to be greatest for vulnerable groups. Alongside people with pre-existing conditions, smoke exposure presents unique risks for pregnant women.

Research shows prolonged exposure to bushfire smoke increases the risk of pregnancy complications including high blood pressure, gestational diabetes, low birth weight and premature birth (before 37 weeks).

These conditions can have short-term and lifelong effects on a baby’s health, with increased risk of conditions including cerebral palsy and visual or hearing impairment. Even babies born only a few weeks early can experience learning difficulties and behavioural problems, and have an elevated risk of heart disease in later life.

So it’s especially important pregnant women protect themselves from exposure to bushfire smoke.




Read more:
How does poor air quality from bushfire smoke affect our health?


Why are pregnant women at higher risk?

Pregnant women breathe at an increased rate, and their hearts need to work harder than those of non-pregnant people to transport oxygen to the fetus. This makes them particularly vulnerable to the effects of air pollution, including bushfire smoke.

We often measure poor air quality by the presence of ultra-fine particles called PM2.5 (small particles of less than 2.5 micrometres in size). These particles are concerning because they can penetrate into our lungs, and into blood and tissue to cause inflammation throughout the body.

Importantly in pregnant women, environmental pollutants can cause inflammatory damage to the placenta’s blood supply. This can interfere with the placenta’s development and function, which can in turn compromise the growth of the fetus.

What the evidence says

Many studies have linked poor air quality, particularly high PM2.5 levels, to poor pregnancy outcomes. Data from 183 countries showed in 2010, an estimated 2.7 million premature births, 18% of the total, were associated with PM2.5 pollution.

A 2019 study of more than 500,000 pregnant women from Colorado looked at the effect of bushfire smoke on pregnancy outcomes. The authors analysed data on air quality, fire incidence and pregnancy and birth records from 2007-2015, during which time Colorado was regularly affected by smoke from fires burning in California and the Pacific Northwest.

The study found PM2.5 due to bushfire smoke was linked to spikes in premature birth, especially in women exposed during the second trimester.

In women exposed to smoke during the first trimester, birth weight was lower than average. Further, exposure during any trimester increased the chance of gestational diabetes and high blood pressure.

The effects were detectable even with low exposure to smoke and small increases in PM2.5. For every 1 microgram/m³ increase in average daily exposure to PM2.5 during the second trimester of pregnancy, the risk of premature birth increased by 13%.

To put this into context, in Canberra in the first week of January, PM2.5 levels averaged more than 200 micrograms/m³, compared with the typical background concentration of 5 micrograms/m³. EPA Victoria classifies PM2.5 levels above 25 micrograms/m³ as unsafe for vulnerable people.




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In another large study, a 24% increase in premature birth was seen after 10 micrograms/m³ increase in PM2.5.

As well as PM2.5, bushfire smoke contains larger PM10 particles, nitric oxides, carbon monoxide and other gases and toxic chemicals. These all have potential to impair lung and heart function in the mother, activate inflammation, and directly affect fetal and placental development.

Smoke threatens fertility, too

Air quality is also a factor for couples attempting to conceive or dealing with infertility.

Population studies suggest air pollution compromises human fertility by reducing ovarian reserve (the number of eggs in the ovary) and affecting sperm number and movement.

Direct exposure to fire, burns and fire retardant chemicals can also negatively impact fertility.




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Precautions to take if you’re pregnant

The best strategy is to reduce smoke exposure as much as possible. Recommendations from NSW Health include staying inside on high-risk days, sealing the house to prevent smoke infiltration and using air conditioning to keep cool.

Avoid creating smoke by cigarette smoking, burning candles, or frying and grilling. Use PM2 (N95) masks and air-filtering devices if possible, and avoid exposure to ash, which contains particulate material you can inhale.

Studies have shown when women are exposed to bushfire smoke during pregnancy, the rates of premature birth increase.
From shutterstock.com

Pregnant women in a fire region should carefully follow emergency services’ direction. It’s better to evacuate early, with an emergency supply kit containing clothes, medications, water and food you don’t need to cook.

Make sure your medication and prenatal vitamins are accessible, continue to take them, and stay well hydrated. Inform authorities and shelters you are pregnant and need to maintain your antenatal care.

Be aware of the signs of premature labour including abdominal cramps or contractions, a heavy vaginal discharge, loss of fluid or vaginal bleeding, pelvic pressure and low backache. Seek help if you think you may be going into labour.

Given what we know about the consequences of poor air quality on pregnancy outcomes, it’s critical pregnant women are given top priority when it comes to bushfire relief and health care support.




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From face masks to air purifiers: what actually works to protect us from bushfire smoke?


The Conversation


Sarah Robertson, Professor and Director, Robinson Research Institute, University of Adelaide and Louise Hull, Associate Professor and Fertility and Conception Theme Leader, The Robinson Research Institute, University of Adelaide

This article is republished from The Conversation under a Creative Commons license. Read the original article.