Bushfire smoke, dust storms and asthma


Image: Bushfire smoke over Brisbane CBD from the Convention Centre, November 11, 2019. David Kapernick © David Kapernick Photography

Images of Brisbane shrouded in an asthma-inducing smoky haze on Monday reminded me of Queensland Ballet’s season launch in 2009. We had driven down for the matinee on a day when a massive dust storm was predicted. By the time we came out, the dust haze was so thick you could barely see the ABC headquarters across the road from the Lyric Theatre.

No doubt those of you who remember that were reliving it on Monday, only this time it was bushfire smoke, drifting in from all sides: NSW, the Sunshine Coast or from Cunningham’s Gap where the highway has been closed since Sunday .

ABC’s 7.30 report invited an air quality specialist on to the programme who judged Brisbane’s air quality on November 11 to be 6 times above the level when air pollution starts to cause problems for people with respiratory problems. On that day, air quality in Queensland’s capital city (population 2.28 million) was worse than China’s biggest city, Beijing (population 21.24 million).

We tend not to get such alarmist warnings on days when plain vanilla air pollution is bad. It is the obvious nature of bushfire smoke (the smell, the poor visibility, the 24/7 media attention), that raises it to public alert level.

The reason health authorities get worried about bushfire smoke in the atmosphere is that the fine particulate matter in the smoke is hazardous to health. Moreover, the longer it takes to clear, the more serious the risk of exposure becomes. Particulate matter known as P10 and P2.5 are harmful to humans and animals: other sources of these fine particulates include power stations, vehicles, aircraft, and dust from unsealed roads, residential wood fire smoke, bushfires and dust storms.

Brisbane’s topography doesn’t help – the city lies in a basin and is prone to temperature inversions, which trap polluted air. Many cities around the world share this fate. Temperature inversions happen when the air is warmer above the pollution that the air on the ground. The smog is trapped, to the detriment of inhabitants in cities including Beijing, Los Angeles, Chengdu, Lima, Milan and Mexico City.

Before we get into air pollution and air quality monitoring, let’s run a short history of asthma, for the benefit of the nine out of 10 lucky Australians who don’t suffer from it.

In 400 BC, Hippocrates came up with the Greek word for asthma (άσθμα), to describe noisy breathing, the characteristic wheezing which so often signals an asthma attack.  Hippocrates (himself) was the first physician to link asthma to environmental triggers and specific, hazardous trades like metalwork.

In layman’s terms, asthma is describes the situation in which you can breathe in but have difficulty breathing out. Someone in the throes of a bad asthma attack is over-inflating their lungs, quite possibly making it worse by hyperventilating.

Medically, it is described as a narrowing of the airways, usually averted by the administering of an inhaled bronchodilator medication or a steroid-based preventer.

Patients presenting at emergency departments with severe asthma are often put on a nebuliser, a machine which administers an inhaled bronchodilator through a mask worn over the mouth and nose.  As I recall, last time I was on a nebuliser (when suffering anaphylaxis), relief was rapid and restorative.

Excuse me if I sound really old, but I recall taking tablets for asthma, before inhalers became commonly prescribed. In the 1940s and 50s, asthmatics were either given epinephrine injections (adrenaline) or aminophylline tablets. As I recall, the latter made me jittery, wakeful and a bit weird, although childhood friends would tell you I was like that already.

Statistics maintained by Asthma Australia reveal the burden of the disease on individuals, their carers and Australia’s health system. The cost of the disease, measured by its long-term impacts, was $28 billion in 2015 ($11,740 per person).

In 2017-208, there were 38,792 hospitalisations in which asthma was the main diagnosis; 44% were for children aged 14 or younger,

People with asthma are more likely to report a poor quality of life, but medical practitioners now are more pro-active about encouraging patients to have an asthma plan. But more needs to be done, with fewer than one in five asthmatics aged 15 and older having a written plan.


Bushfire smoke at Yangan, drifting in from Spicer’s Gap. Photo by Bob Wilson

(Note to self: this includes you, Bob. Make sure you have a spare puffer for times when (a) the puffer runs out (b) you have lost or misplaced it or c) the air looks like this).

The rate of deaths from asthma has remained stable since 2011. There were 441 deaths due to asthma in 2016-2017.

Mortality rates are higher for people living in remote or lower socioeconomic areas, and for Aborigines and Torres Strait Islanders.

Meanwhile, parts of Queensland and NSW remain shrouded in bushfire smoke. Numerous scientists and firefighters have voiced concerns that this may only be the beginnings of a long, dry and bushfire-prone summer. Climate change-denying pollies bewilderingly blamed the Greens for conspiring to limit hazard reduction burns.  Cathy Wilcox brilliantly summed this up in a four frame satirical cartoon (2nd one down the page).

The Guardian took the fact-checking route.

On November 11, the World Air Quality Index rated several areas of Brisbane including Rocklea, South Brisbane, Woolloongabba, Wynnum, Wynnum West, Lytton and Cannon Hill as ‘very unhealthy’.

The state’s chief health officer Jeannette Young told the ABC that everyone should stay indoors for the next 24 to 48 hours.

“Treat this seriously and don’t be complacent. Whether you’re in Logan or Lowood or anywhere in between, everyone needs to limit time spent outdoors while these conditions remain,” Dr Young said.

The term “particulate matter” – also known as particle pollution or PM, describes the extremely small solid particles and liquid droplets suspended in air. PM can include soil dust and allergens and their size affects their potential to cause health problems.

PM10 refers to particles with a diameter of 10 micrometres or less (small enough to pass through the throat and nose and enter the lungs).

PM2.5 refers to smaller particles able to enter the blood stream, causing serious adverse health effects over time.

So what’s ‘normal’ and how does that compare to Remembrance Day in Brisbane? The World Health Organisation (WHO) says the average PM2.5 level of cities across the globe measured over a 24-hour period is 35µg/m (or 3.5 micrograms per cubic metre). An ideal level of pollution (no negative health impacts), is 25µg/m.

The Brisbane CBD was at a PM10 and 180µg/m at 9:00am on Monday – 10 times the amount of pollution on an average day.

As we so often blithely say: ‘it’s a first-world problem’.

The WHO estimates that 1.6 million people die every year in India from air pollution. India has some of the most polluted cities in the world. This report from the BBC attributes air pollution in Delhi to motor vehicles, construction and industrial emissions, the burning of crop stubble and the residue of fireworks set off for a Hindu festival.

In early November P2.5 levels in Delhi were seven times higher than Beijing in early November, the report said.

If you were paying attention, those comparisons also applied to Brisbane on Remembrance Day, 2019. Lest we forget.

Further reading: https://blissair.com/what-is-pm-2-5.htm



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