How much exposure to asbestos dust will begin to cause health problems?

So, for quite a while I’ve been hearing people say that the tiniest amount of dust will have serious consquences in the future. Is that true? Surely it can’t be. I’ve also wondered about the asbestos towels the Romans used because they were extremely durable. How safe were those things?

Any exposure can cause serious health problems. It’s not that the more exposure, the more serious the health problems, but rather the more exposure, the greater chance of serious health problems.

You could be very unlucky, and after minimal exposure suffer serious health problems. Or you could be very lucky, and after significant exposure suffer minimal or no health problems. SFAIK there’s no “safe level” of asbestos exposure, if “safe” means no chance of serious health consequences.

It’s /ALSO/ the more exposure, the more serious the health problems.

Dust gives you dose proportional dust damage.

Asbestos (and structuraly similar non-asbestos materials) may also give you mesothelioma.
I don’t think I’ve ever seen a “magic” level at which dust damage becomes “serious”, I think that the more dust you breath, the more damage it does. Even people who get to the end of life without serious disability gradually breath less effectively. If you die at 55 with obvious scarring, it was serious. If you die at 95 with no obvious scarring, it wasn’t.

The good news is that all dusts, including asbestos, are less damaging if you don’t smoke. Smoking interferes with the mechanism that blocks and removes dust, so your dust load is much much worse if you smoke. If your only exposure was a small amount when you were a non-smoker, you won’t have significant asbestosis, (and also probably won’t get mesothelioma).

Asbestos is a risk factor for serious disease. Knowing if the exposure to risk function drops down to zero at some small amount is virtually impossible to determine.

Try to think of it, extremely roughly, as exposing yourself to dangerous bacteria. The fewer bacteria the lower the risk it will result in your death, but even if it is just one, there’s still a chance it establishes a colony behind your ears (where you never wash) which one day gets the opportunity to invade and conquer.

Dust always causes scarring proportional to exposure.

It is probably not a linear relationship. It is probably possible to overwhelm some of the protective mechanisms. (I mean, ignoring the fact that if your lungs fill up with dust you’ll die). But it is not just a risk.

It depends.

Some people have had health problems with a small exposure.

I trained and worked on ships for about 5 years. Then worked in boiler rooms for a few years with out PPE. My exposure was limited. And my last exposure was over 40 years ago. I am not showing any health problems.

My dad shipped for 15 years in the merchant marine as an engineer. The he worked 40 years in the ice and cold storage industry. With his boiler experience he did all the work on the glycol boilers. He smoked most of his life. He lived to be 79 and had not problems from asbestos.

So it depends.

Worth pointing out that there are two kinds of asbestos to worry about.
Serpentine and Amphibole. The former is white asbestos, whilst the latter includes all those with long thin spiky fibres, including blue asbestos. White asbestos is the most common (up to 95%). It has generally been thought that it is the Amphibole family that is the greatest risk for mesothelioma. The longer fibres causing more scarring and generally more damage. White asbestos is fluffier and has shorter fibres. The down side of those is that they stay in the air longer and may burrow deeper into tissue. Which certainly makes it good for asbestosis.

Certainly here in Oz, it is the Wittenoon blue asbestos mine that is the villain, with a tragic number of mesothelioma sufferers.

If you avoid getting fibres into the air and breathing them, asbestos isn’t a hazard. But for the OP, mesothelioma takes anything up to 40 years to manifest itself. Romans probably died of other causes before, or if they did succumb, it would not have been noteworthy versus the other ills expected.