I am convinced that the air we normally breathe is a kind of water, and men and women are a species of fish.

– D H Lawrence, English writer and poet

No, this piece has nothing to do with virus. Aren’t we already sick and tired from reading or watching endless reports of doom and gloom? What I wish to share are my observations over the years on the air we breathe that many people may not realise.

To survive, we need to inhale air with oxygen and expel carbon dioxide produced by cells in our body. This exchange of air and carbon dioxide takes place in our lungs and the rate can vary according to effort, efficiency and oxygen content in the air.

Cardiovascular exercise such as jogging and swimming increases both heart rate and intake of air dramatically. Air could also be introduced deep into our lungs when sitting still but few people bother to learn proper and deep breathing.

This explains why some of us are energetic and look years younger, while others appear tired and haggard beyond their years from lack of oxygen. Interestingly, plants produce oxygen and animals carbon dioxide, and one could not survive without the other.

By volume, dry air can comprise 78.09 percent nitrogen, 20.95 percent oxygen, 0.93 percent argon, 0.04 percent carbon dioxide, and small amounts of other gases. Air also contains a variable amount of water vapour, on average around 1 percent at sea level, and 0.4 percent over the entire atmosphere.

Humidity, which is the amount of water vapour in the atmosphere, can be good and bad. Malaysia is not extremely hot but very humid. We feel hot and sticky when invisible sweat stays on our skin. Dry air facilitates evaporation which cools the body, but the downside is dry skin.

Although air is rich with oxygen in a jungle, the amount in the middle of an ocean is still enough for us to breathe normally. It is only high up in the mountains when air becomes thin and not enough air is inhaled through normal breathing.

Contrary to popular belief, scuba divers breathe in normal air and not oxygen when submerged underwater. Although breathing in pure oxygen is not fatal, it can be harmful if prolonged. However, breathing in only carbon dioxide or nitrogen is suicidal.

A common horror scene in movies is showing people trapped in airtight rooms and die once oxygen is depleted. But this has not deterred many people sleeping in air-conditioned rooms with windows and doors sealed so that no air or insect can enter.

Unlike large hotels, office buildings and shopping malls designed with centralised air-conditioning system that takes in fresh air, budget hotels and homes are fitted with individual air-conditioners that continue to circulate the same stale air within the room.

Many of these rooms are closed when not in use to remain cool when they should be ventilated by leaving windows and doors open. Residences and offices using room air-conditioners should have ventilation fans installed at the toilets and kept running to suck out stale or stinky air.

In many bedrooms, the gap below the door allows some air to pass through. But if budget permits, install another ventilation fan to suck in fresh air with a gauze fitted to filter out insects, and particularly useful in heavy rain without air-conditioning.

Air is transparent and the presence of dusts goes unnoticed until we shake a piece of cloth like a towel in a sunbeam. The large number of visible particles in the air would induce us to walk away although they are present everywhere.

But what make us feel down and affects our health is the haze, which is easily noticed when visibility is reduced. The severity is measured using the Air Pollutant Index, which can range from good to moderate, unhealthy, very unhealthy and hazardous.

These readings take five things into account: ozone (O3), carbon monoxide (CO), nitrogen dioxide (NO2) and sulphur dioxide (SO2), as well as the concentration of 10 microns (PM10) particulates in the air.

In normal times, I suffer not from particles in the air but gas which can be smelled. This can be trying when stuck in an elevator with people emitting strong body odour or their clothes stinks when not fully dried or have picked up fumes when foods are fried in strong-flavoured oils.

Most drains in cities and towns are covered but the gaps may emit fumes which can be toxic as workers have died in them while carrying repair works. In my childhood, I have tunnelled through drains that ran perpendicular to roads to catch catfish and emerged fully covered with mud.

But I survived.

The views expressed are those of the author and do not necessarily reflect the official policy or position of the New Sarawak Tribune.