The air is drawn in from outside through wetted filters and we have to keep some leeward windows at least partly open to allow circulation.

Our lived experience is that if we run the system to keep the temperature at a comfortable level, the air inside the house smells fresher and cleaner than outside, especially on days of heavy pollution when the difference is very noticeable.

Maybe that is just us persuading ourselves that it is so, but surely wet filters should help? Has any research been done about this question? Does anybody know the real answer?

1917 is the greatest load of codswallop I can recall in a lifetime of moviegoing. The script is improbable when it is not impossible.

Its premise is nicked from Gallipoli. It would not be worth mentioning except that it won at the Golden Globes and is in contention for the Oscars.

Not to waste more of everyone's time than is necessary to expose this junk for what it is, I shall follow one thread.

The protagonist has come upon a farmhouse that has been deserted for quite a while. However, in the yard he finds a pail of fresh milk. Camera shoots to cow on hill. We have to work out for ourselves that the cow has milked itself and put the cover on the milk pail.

The discovery is just as well because the corporal has used up all the water in his canteen washing the dust out of his eyes after being buried alive before engaging in the film's first "video game" chase. (What a pity he did not pour the water over Sam Mendes to wash the bulldust out of his eyes).

So he fills the canteen but is not thirsty enough to drink any of it. This is just as well because, at the end of the next video game chase, he takes refuge in a basement where he is awakened by the touch of a woman's hand on his neck.

Don't panic: no love interest is involved. Instead she has a babe in her arms. Soldier boy immediately offers her all his rations. Despite his having been on the road for a day he has not eaten anything.

She says in French that the baby needs, you guessed it, "milk". Fortunately, although neither can speak the other's language, they are able to read the subtitles. Puzzlement vanishes from the soldier when he remembers the milk.

I am not making this up. 1917 and Hollywood deserve each other. If you want to watch a great war movie chase up The Captain (Der Hauptmann).

As I struggle to come to terms with my loss, and our country's situation, one thing stands tall and brave and clear. The real Australians of the year are a mixed bag of the young and old and in between and come from every ethnic background.

They rush toward danger to keep us safe. They stand together when things get tough. They bend, they do not break. They try, and try, and try.

I don't know what the "rules" are for "Australians of the Year", but I know the truth.

The firies are the best we, or anybody else, could have. Give the brave yellow line the credit they have earned.

I read with interest Professor Martin's "Could 2020 be the year of the ethical workplace?", (canberratimes.com.au, January 13, 2020).

Martin's assertion "bosses ... would be well advised to dedicate time, effort and resources to establish an ethical business culture well before a crisis can rear its ugly head" is an example of "an ounce of prevention is worth a pound of cure".

It is a noble ideal but, without ramifications for wrongdoing and a means to investigate and punish, such as federal ICAC, unethical bosses aren't going to change.

The corporate environment rewards psychopathy and puts profits ahead of "doing the right thing".

Workers are just one of many exploitable resources. If the worker suffers that is ultimately considered their personal weakness or failure, not a symptom of workplace culture or workload demands.

Until we make bosses and business owners truly accountable this kind of wishful thinking is just virtue signaling and finger shaking.

Despite the immense social, economic and environmental costs of the bushfire crisis the government continues to argue its policies strike the right balance between climate action and jobs.

Mr Morrison, wake up and smell the smoke and seek advice from the likes of Ross Garnaut on how to best transition to a low carbon economy.

In doing so Australia could be an exemplar and make a real contribution to limiting the increase in global temperatures.

I am not a fervent royalist or republican but the current situation seems to have been brought about by pack-attack bullying by the gutter press.

Just what they love to complain about in juicy articles, they are guilty of doing themselves. The petty journalists can't even get the Duchess's name right.

Such attacks have happened before. There is always a problem being the second son.

The gutter press has turned on Prince Andrew but he is well down from second spot now. Prince Harry himself is now well down the list of succession and has to do something with his life.

I don't see this as destroying the monarchy: that is simply journalists trying to ram opinions down the throats of readers.

Before Paul Feldman starts pumping Terry Snow's tyres (Letters, January 13) he needs to get his facts correct regarding parts of the Currowan fire which roared into the village of Bawley on Thursday, December 5.

The two ferocious fire fronts, emanating from the north east, centred on Weemala, Thrush and Oriole Streets and Bawley Point well to the north of Terry Snow's property. If not for the courageous efforts of the Bawley and Kioloa RFS units aided by fire and rescue crews most of the houses in this area would have been lost.

Credit must also be given to those units which answered numerous calls to Terry Snow's Willinga Park in the preceding days to put out spot fires and ember attacks. If not for their due diligence, as well as the tireless work of two of his employees, Mr Snow's property may well have suffered substantial fire damage.

The build at Willinga Park is a credit to Mr Snow's vision and perseverance but the costs to make that vision a reality are well out of the league of most councils.

Bawley and Kioloa are two of the most pristine villages on the South Coast. Most people living in this environment are more than happy to do so.

The Prime Minister's defence of his government's climate change policies during the bushfire crisis has missed the point.

Yes, it is a global problem that requires a global solution. Yes, Australia's direct contribution to greenhouse gases is relatively small.

But for this defence to have any credibility, Australia should be at the forefront of international efforts to address the crisis.

On the contrary, Australia has been seen to be opposing more ambitious global targets and pretending to "meet and beat" existing inadequate targets through accounting fiddles.

Just as rising sea levels have driven Pacific Island leaders to step up as among the most vocal and impactful advocates of strong climate action, this season's unprecedented bushfires provide Australia with a powerful narrative to argue for more dramatic global action.

Worldwide sympathy about our bushfires provides us with a potent opportunity to step up and drive global change.

We can't do that from a position of weak domestic policy; credibility is critical.

There is so much concern about the extent of bushfire caused koala habitat loss but so little attention paid to the much larger area of habitat loss caused by the encroachment of suburban development into bushland.

This is caused by the same forces driving climate change: too many humans demanding, per capita, too much from nature.

Email: letters.editor@canberratimes.com.au. Send from the message field, not as an attachment. Fax: 6280 2282. Mail: Letters to the Editor, The Canberra Times, PO Box 7155, Canberra Mail Centre, ACT 2610.

Keep your letter to 250 or fewer words. References to The Canberra Times reports should include date and page number. Letters may be edited. Provide phone number and full home address (suburb only published).

To send a letter via the online form, click or touch here.