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Australia's Clean Air Myth

I've been thinking a lot about air quality in Australia recently as I wrote up my submission in response to Victoria's Air Quality Statement, which will help shape a future air quality strategy for this state.  The Clean Air Statement presents a rosy picture for air quality in Victoria - our air is repeatedly described as "great" and "very good" - and this leaves the impression that air pollution is not a current health danger to Victorians.  Anecdotally, I have seen this attitude adopted by Australians around the country, who ask me why I need to research air quality in Australia and tell me that we already breathe clean air.  It is true that our air is cleaner than many of our neighbours, but this doesn't mean that it is healthy.  Air pollution in China, for instance, is one of the biggest handbrakes on development in what may soon be the world's biggest economy, and it is meaningless to compare it to Australia.

So, how big is Australia's air …

Mixed Results in Air Pollution Scorecard

Air pollution is responsible for 7 million deaths annually, with 9 in 10 people worldwide breathing polluted air, according to new estimates from the the World Health Organization (WHO).

The WHO identify air pollution as a major global health concern, contributing to heart disease, stroke, cancer, and respiratory diseases.  To help address this they set guidelines for safe exposure limits to key pollutants including particulate matter (PM), ozone, and nitrogen dioxide, and also maintain a global air quality database which tracks PM2.5 and PM10 levels in 4000 locations worldwide.

Peering into the WHO data there are good and bad stories to tell.  Air pollution deaths are concentrated in South East Asia and the Western Pacific, where poor air quality coincides with high population densities.  Interestingly the latest data shows that the worst affected cities in these regions are predominantly in India, whereas air quality in China appears to be improving in the wake of citizen action and…

Fake Plastic Trees

Air pollution is a big deal - it kills millions annually - but we aren't going to make progress in dealing with it by planting fake plastic trees in the middle of the world's cities.
When you attempt to reduce air pollution it is much easier to do it at the concentrated source - and easier yet to stop these compounds being formed all together - than it is to do once they've been released and diluted to one part per million or billion.  But yet again we see another story / press release about a tech startup trying to do just this.

The Crown Estate claim to have planted a small number of their CityTrees in several first world cities - cities with air quality issues, yes, but not on the level of their counterparts in the developing world.  These devices, like many others out there, are designed to suck in dirty air and purify it. They then release clean air to mix back in with the urban plume, where it can modestly dilute the remaining pollutants.  When you try and picture t…