After stepping out in Sydney on Tuesday, it will feel like you have smoked three packets of cigarettes – at once.
The streets are blanketed in thick smoke, the sky is orange, the smoke is seeping into buildings and residents are struggling to breathe.
The air quality in Sydney is the worst in the world today, according to one measure
Due to bushfires across New South Wales, the air quality in Sydney dropped to record lows on Tuesday, with the air quality index (AQI) showing a reading of 2000 in some areas. For context: A hazardous reading is 200.
At 3pm, the east of Sydney had a AQI reading of 1647, Sydney's north west recorded 1722 and Sydney's south west hit 1473. The air quality was worse in Sydney than in those places affected by bushfires, such as Coffs Harbour and Port Macquarie. According to the World Air Quality Project, Australia has the worst air quality in the world on Tuesday.
The unusual conditions have many asking: what is the health impact from smoke inhalation and hazardous air quality?
The health impacts of smoke inhalation
In good news, the conditions aren't likely to remain a long-term issue, like seen in countries such as India and China, and the impact of short-term smoke inhalation doesn't have the same affect on your respiratory health as longer term exposure. The difference between years of pollution compared to days of pollution is that long-term pollution can cause diseases and increase disease progression, while short-term pollution is more likely to exacerbate pre-existing conditions such as asthma, according to NSW Health.
There are many components in bushfire smoke but the main concern is the increase in particles in the air and the inhalation of these particles. The particles are measured based on their diameter, with PM10 particles having a diameter less than 10 micrometres and PM2.5 particles having a diameter less than 2.5 micrometres. According to NSW Health, PM10 particles can pass through the throat and nose and enter the lungs or affect the heart, while PM2.5 particles are so small they can go deep into the lungs and enter the bloodstream. PM10 also contains PM2.5 particles, making it even more dangerous.
After short-term exposure to particles, residents can expect to have irritated eyes, nose and throats, NSW Health Director of Environmental Health, Dr Richard Broome said in a statement emailed to Lifehacker Australia. He noted it is much more problematic for people with asthma, emphysema and angina as the smoke triggers the symptoms.
Associate professor at UTS Brian Oliver, who focuses on respiratory diseases, said the pollution levels are extremely high and dangerous.
"The level of pollution we are experiencing in Sydney is dangerous for everyone, and people with preexisting health conditions should avoid being outside, and seek medical care if they feel ill. The risks are highest for people with respiratory or heart conditions," he told Lifehacker via email.
Ivan Hanigan, a researcher on the health impacts of air pollution at the University of Sydney, said the small particles (PM2.5) can trigger chronic obstructive lung disease. "Other problems of our respiratory system include ailments such itchy eyes and sore throat or more debilitating conditions including asthma and allergies. Additional problems can occur in the cardiovascular and immune systems and even change in some metabolic functions," he said via email.
"Healthy people will generally bounce back quickly from a short duration bushfire smoke event. Research on the health effects of medium-term exposure to fire smoke (weeks and months rather than days) is limited."
Hanigan pointed to a study by researchers from the Centre for Air Pollution, Energy and Health Research (CAR) involved in the Hazelwood Health Study, which is investigating the health outcomes of populations exposed to 6 weeks of smoke from the 2014 Hazelwood coal mines in Victoria. "They found more than a year after the fire occurred adults had increased rates of respiratory symptoms," he said.
Data from NSW Health shows there has already been an increase in hospital admissions for people with respiratory and cardiovascular conditions with higher than average hospital presentations for a third straight week. Researchers from CAR said bushfire smoke can lead to an increase in hospitalisations.
"Research has shown that increases in PM2.5 from bushfire smoke are associated with increased intensity and frequency of disease symptoms, increased use of asthma medication, increased healthcare attendances, respiratory hospital emergency admissions and cardiovascular problems including cardiac arrest, and mortality," the centre said in a factsheet released in December.
"CAR researchers estimated that in Sydney over the period of 2001-2013, smoke from 184 bushfire incidents was associated with 197 premature deaths, 436 cardiovascular hospitalisations, and 787 respiratory hospitalisations."
How to protect yourself from the smoke in Sydney
The number one way recommended by health professionals to protect yourself from the smoke is to stay indoors and limit physical activity. The smoke conditions in Sydney will thankfully pass.
NSW Health has warned people to reduce their outside physical activities and sensitive groups to avoid all outdoor activity. “NSW Health continues to recommend that people with these conditions should avoid outdoor physical activity when there’s smoke around,” Dr Broome said.
Hanigan told Lifehacker Australia that people should close windows, doors and try to seal your home from the smoke. They should also avoid using the kitchen exhaust fans, which can cause negative pressure and draw in outside air to replace inside air. If you use an air conditioner, put it on to recirculate the indoor air.
"Take advantage of periods when the smoke has dissipated to ventilate the homes by opening the doors and windows and let the breeze through, then close the house up again if the smoke returns. Seek shelter in libraries and shopping centres," he added.
According to the Centre for Air Pollution the only scientifically-backed way to increase air quality in the home is with an indoor air cleaner that has a HEPA filter. Humidifiers, negative ion generator and odour absorbers do not reduce air pollution.
You can also buy a mask, but be sure to do your research as only P2 masks prevent particles from getting through. PM2.5 particles, for example, are so small they can pass through other masks, according to Dr Broome.
"The main concern with smoke is the very fine PM2.5 particles, which are so small they pass through most types of mask. A P2 mask does filter out these particles, but is only effective if there is a good fit and an air-tight seal around the mouth and nose. Evidence shows that this is difficult to achieve in practice, so they may not provide the benefit people are hoping for," he told Lifehacker Australia.
In other words, if you want to protect your lungs: stay indoors.
New South Wales is currently suffering through a severe smoke haze, as strong winds spread bushfire smoke across the state. While many have turned to filtered masks for protection against the pollution, not all masks are effective in protecting against smoke inhalation. For the best protection, you'll need a P2 mask — the kind usually worn by builders.