She was considering my request for one of the masks the government is issuing free of charge to seniors to help us to endure Canberra's particle-infested air.

I assured her that, yes, I was well over 65, but told her how I could understand how she was deceived by my face, it being such an unlined testament to my lifetime of clean living, to my lifelong Christian abstinence from the sorts of unmentionable habits that can make a man haggard.

Sceptically, she stared and stared at me in search of something suggestive of a qualifying age. She must have found something (perhaps a gnarled ear lobe, perhaps a wisened eyelid, perhaps a tell-tale trace of grey in my flaxen locks) for, grudgingly, she reached into a box and handed me a mask.

"Do you have any other colours?" I wondered, disappointed by the white mask's drabness.

"Anything in lilac? In Raiders' green?"

But no, for the time being white is all there is. Perhaps, if this mask wearing becomes commonplace, a necessity of every Canberra summer, entrepreneurs will begin to cater for individuality, for those of us who like everything we wear to make a statement about who and what we are. Perhaps there will be whole-of-face novelty masks, with in-built particle resisting features, enabling us to go out into the murk as Darth Vader, as Shrek, as Barnaby Joyce (although that might scare children) or as our favourite member of the Royal Family.

But I digress because I want to say that with breathing suddenly become so difficult and so fraught (perhaps for the first time, for most of us) I have been investigating what breathing actually is. Here I am, over 65, having always taken it for granted having grown up in an English seaside resort blessed with health-giving sea air (tinged with perfuming nuances of salt, decomposing seaweed and fried fish and chips) that holidaymakers flocked to enjoy, and then having lived for decades in Canberra where the air is, usually, magically pure and cheek-tinting.

Doing some breathing homework to try to dispel my extreme ignorance I found just what I wanted in the online Aeon magazine and in M.M. Owen's ripper essay Breathtaking.

"Cut out of the chest and held up to the light, the human heart is shiny as a ripe, purple grape. The lungs are shaped like a pair of heavy wings," Owen explains, vividly.

"It all looks very damp, very vivid, and very strong. From the day that we are abandoned by the umbilical, until the day when the last fires will wave to us, this fleshy equipment stands between us and non-existence. And yet: unless (until) it malfunctions, we tend to barely consider it.

"As the biology of gas exchange evolved, skin was superseded by gills, and gills were superseded by rudimentary lungs.

"In mammals, the lungs became the powerhouse, existing at the centre of a process that goes like this: on inhale, the diaphragm flattens downward and the intercostal muscles lift up the ribs, expanding the volume of the lungs. As volume increases, air pressure decreases relative to the atmosphere, and air rushes in.

"Mammalian lungs are covered with millions of microscopic balloons called alveoli; through their infinitesimally thin walls, the oxygen in air is picked up by the red blood-cell protein haemoglobin and carried to the ever-ravenous cells. Carbon dioxide travels in the opposite direction, transferred by the alveoli to the soon-to-be-exhaled air. On exhale, the diaphragm and intercostal muscles relax. The decrease in lung volume results in increased pressure relative to atmosphere, and so the air rushes out. Thus, a single breath. Repeat until death."

I'm reminded that one of the many things that used to so impress admirers of the supernaturally wonderful dramatic soprano Jessye Norman (she died in September and will continue to impress sensitive mankind forever with her recordings) were her feats of breathing. Her mammalian lungs really were her and her highly-trained voice's powerhouse. They helped enable her to sing with superhuman, cathedral-rattling power and to hold notes (boomed or whispered) for ever and ever, Amen, where mere, mortal mammals have to take ambience-interrupting breaths.

She was one of those rare souls (Roger Federer is another, in his very different field of the arts) who in going about their work of entertaining us remind us of what a piece of work is man, what a thing of wonder the human body is.

Breathing and its taken-for-granted marvellousness is today's column's theme and here, just published this week in the online Artforum in the piece Last Songs For Jessye Norman, is poet and performer Wayne Koestenbaum on that very subject.

"In videos of Norman singing, watch her breathing. Observe her complete bodily vessel accepting inspiration. Note how decisively she admits air: She must seize oxygen to sing the phrase we are waiting to hear. No one else but Norman can take in those invisible molecules. She must now, even with you watching, admit material to propel the breath that will unleash and uphold the upcoming phrase. She opens her mouth. Her shoulders rise as her lungs expand. She sings. She sang - and now your responsibilities [the appreciation of her voice, of the works she sang] begin."