Last week, there was a fire in West Perth. I don’t know anything about it other than what I heard on the news reports, in which their was concern that it may contain asbestos.
What is this stuff and why is it so nasty?
It has been around for many years and with the advent of the industrial age it has been used extensively in buildings as a result of some very desirable properties: it is an excellent insulator for heat and electricity, it is chemically resistant, and it is not prone to either UV degradation or biodegradation.
And as the knowledge of toxicology increased, and our understanding of the many complex pathways by which various industrial chemicals could interact with our body advanced, asbestos certainly raised no flags – it was, after all, nothing more than a silicon-based mineral.
But of course in the latter part of the last century it began to be linked with cancer, and that link is now well and truly established.
In a classic case of “oops – we didn’t think of that.” the only attention that was paid to this material was its chemical properties, and no one considered the impact its physical properties could have.
In fairness, this is most likely because these properties were not understood in the same way that they are now.
Now remember something here – this nasty nasty material that has caused, and will cause, so many deaths, is a natural material. Like arsenic and cyanide it is natural. So let’s not buy into this trendy view that natural things are good for us, and synthetic things are bad for us – it’s just nonsense.
Well, what exactly is the problem with asbestos? And why don’t other types of dust cause cancer when we breath it in?
Well, as it happens, asbestos fibres fall into a critical size range. Our lungs are full of tiny little compartments called alveoli, which are fed by billions upon billions of tiny little channels. It turns out that if you breathe something in that is smaller than 1 µm, it just comes in and goes straight out again. If we breathe in something that is greater than 10 µm, then it doesn’t get in. But if something falls in the range 1 µm to 10 µm it is small enough to get in but not small enough to get out again, and so it gets stuck in there.
And it is generally thought that this foreign material, although it is chemically inert, is the cause of cancer. Interestingly, there is a synergistic effect with cigarette smoke. That is, if you smoke and have been exposed to asbestos, your chances of contracting cancer are far greater than the additive probabilities of the asbestos and cigarette smoke alone. This also suggests some sort of physical mechanism.
In fact, this is one of the things that has come out of the 9/11 (shouldn’t we call it 11/9 in Australia?) terrorist attacks.
Although there were 3000 people killed when the buildings collapsed, there have been many others – an unknown number – that have contracted cancer as a result of breathing in the fine dust that the pulverised buildings created.
Due to the unprecedented force of the building collapse, microscopic and lethal dust particles (not ordinary dust, the pulverised building material, much of which probably was asbestos) filled the air in massive proportions and anyone who was unlucky enough to breathe at has been exposed to the risk of cancer.