The air quality in Brisbane is currently worse than Beijing as haze from bushfires burning across Queensland and New South Wales blankets the south-east corner.
The Department of Environment and Science's live air data rates air quality conditions as very poor across Brisbane and into the Gold Coast.
According to "The World Air Quality Index" the air quality is rated as very unhealthy, across several areas of Brisbane including Rocklea, South Brisbane, Woolloongabba, Wynnum, Wynnum West, Lytton and Cannon Hill.
It is also assessed as unhealthy at Springwood in Logan, south of Brisbane.
What does that mean?
What those ratings mean is that the air quality is so bad it is at an emergency level, and likely to be affecting the entire Brisbane population to some extent.
Poor air quality can irritate the eyes, nose and throat, cause shortness of breath, aggravate asthma and other respiratory conditions, and affect the heart and cardiovascular system.
Breathing polluted air for a long period of time can cause more serious problems.
The state's chief health officer Jeannette Young has issued a formal alert and is urging everyone to 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.
"And if you have outdoor events planned this week, limit time outside or reschedule them. Nothing is worth compromising your health for."
What has caused it?
The Bureau of Meteorology (BOM) said much of the smoke was blowing up from the fires in northern New South Wales.
"It is just this little south-easterly breeze that we've had come in this morning it's recirculating all the smoke off the northern NSW fires and sort of pushed it out to sea on the westerlies and this little south easterly this morning has brought it all back in from over the water," meteorologist Jonty Hall said.
Likewise, BOM meteorologist Dan Narramore said the smoke haze showed no signs of dispersing anytime soon.
"We have widespread smoke in southeast Queensland with east-south-easterly winds dragged it from fires in NSW and southeast Queensland as well," he said.
"The smoke should hang around for most of the day before a north-easterly wind change later today and the winds should clear the smoke tomorrow."
Brisbanites saw a similar haze blanket the city during the September fires which mostly cleared within 24 hours.
But this time, forecaster Vince Roland said, the thick smoke could linger until the weekend.
"As we head towards the middle and end of the week we see the wind swing back around to the south, so even though we might get a bit of clearing tomorrow there is going to be a lot of smoke hanging around the northern parts of NSW and south-east Queensland," he said.
"So we'll probably see a few more hazy conditions before the weekend."
What you can do
Queensland Ambulance Service spokeswoman Kowai Timu said people with pre-existing lung conditions like asthma and emphysema needed to take extra care.
"It is hard to determine if the jobs we are going to are specific to the smoke we are experiencing in the south-east.
"But there is more potential and more risk with all these fires generating so much smoke."
If you are really struggling, a special face mask, called a respirator, can be effective at keeping out pollution.
Education Minister Grace Grace said schools would be taking precautions where smoke was an issue.
"The Chief Health Officer has advised that where air quality is poor across Queensland, students and staff should remain inside classrooms," she said.
How this compares to elsewhere
In comparison, Beijing — which is often held up as the barometer of poor air quality — was assessed as unhealthy on Monday.
Only people sensitive to respiratory problems in Beijing are likely to be experiencing more serious health effects.
In fact very few cities including Khorramabad in Iran, Secunda in South Africa, Bain al Jessrain in the UAE, Igdir in Turkey, Durango, Mexico, Panipat and Bandhavgar Colony in India, have a worse air quality that is deemed hazardous.
Crunching the numbers
This part is for those of you wanting to know and understand what the air quality data says.
Experts use the term "particulate matter" — also known as particle pollution or PM — to describe the extremely small solid particles and liquid droplets suspended in air.
PM can be made up of a variety of components including soil, dust and allergens and their size affects their potential to cause health problems.
PM10 refers to particles with a diameter of 10 micrometres (microns) or less and these particles are small enough to pass through the throat and nose and enter the lungs, causing serious health effects.
PM2.5 refers to smaller particles with a diameter of 2.5 micrometres or less and these particles are able to enter the blood stream, causing serious adverse health effects over time.
It is important to note, a PM10 rating includes the smaller PM2.5.
For comparison, a typical human hair is about 100 micrometres.
The World Health Organisation issues a guideline for PM to regulate air quality, and in turn, reduce air-pollution related deaths.
The average PM2.5 level of cities across the globe, as recorded over a 24 hour period, currently sits at 35µg/m (or 3.5 micrograms per cubic metre)
An ideal level of pollution, where it does not have negative health impacts, is 25µg/m.
But Brisbane's current guideline for PM10 is 50µg/m.
Now that's out of the way, this is where the numbers stand across the Brisbane region:
According to the Queensland Government air quality data shows both Southport and Woolloongabba are suffering very poor air quality — at PM10.
The Brisbane CBD was at a PM10 and 180µg/m at 9:00am (Premier Annastacia Palaszczuk said it was 10 times the amount of pollution on an average day).
