New Zealand’s unhealthy home-heating in the age of COVID-19: Part 1: Does air pollution make diseases like COVID-19 worse?

Donald Trump may not appreciate what the World Health Organisation has contributed to the management of this crisis, but one of the many things that it has done is co-ordinate the release of numbers. We’ve all been watching the numbers, almost in real-time, describing the rise and fall of COVID cases. But for scientists - numbers are our raw materials. For the many of us feeding on the numbers as they came in, it became clear early on that some countries were faring differently than others.

Whereas kiwis eagerly looked for evidence that our early action had prevented a disaster, others quickly noticed that those places fairing worse had a number of things in common, one of which was a pre-pandemic history of poor air quality. (Follow these links to find out more: link1, link2, link3)

This is not a big surprise to us with experience in air quality and health. We have long known that exposure to air pollution has two main effects on health. The first so-called ‘acute’ effect arises from temporary exposures to highly polluted air – lasting from hours to a few days. Thousands of studies across the world over the last four decades have proven beyond doubt that while many of us experience nothing more than mild annoyance, those with pre-existing health conditions can experience an “exacerbation” of their condition – which can range from a ‘flare-up’ of asthma requiring extra inhaler use, to much more serious consequences including a trip to intensive care and even death. In other words, air pollution becomes a ‘trigger’ for an attack. This affects not only people with respiratory conditions, but cardiovascular conditions as well, with arrythmias, strokes and heart attacks also triggered by these so-called ‘episodes’ of air pollution.

The second, or ‘chronic’ effect, is more subtle but insidiously damaging. This is where the repeated or continuous exposure to air pollution over months and years takes a long-term toll on the body, but one which develops imperceptibly. Because the development is so slow it is very difficult to prove cause, but many thousands of studies have found that people with chronic exposure to air pollution are more likely to develop a wide range of chronic health conditions and vulnerabilities, including birth defects, stunted lung development in children, development of cancers, and emergence of the very conditions that make people vulnerable to those acute air pollution episodes.

So, the more air pollution you’re exposed to in virus-free conditions, the harder a virus is likely to hit you, and – if you survive - the harder it will be for you to recover.

However, if you look at this from a different point of view, we can draw a simple, positive conclusion: clean air provides some protection from the current, and other viruses.

To be continued...