Toxic Collecting

[willedoo]

On the subject of collecting - apologies in advance for sounding like a cracked record, as I've mentioned this before on another forum, but it's worth noting.

 

As we all know, there's various hazardous substances present in aircraft components, eg. asbestos etc..

 

One that is often overlooked is the presence of radium paint ( glow in the dark lettering) in older aircraft gauges. Most of it was phased out in the 60's so it usually applies only to gauges of older vintage. Over time, the paint can degrade and produces a fine dust or powder which can be absorbed into the skin, but is most risky when inhaled.

 

If the gauge is well sealed with no cracked glass or perished seals, most will not register any noticeable emissions.

 

But for people who collect a lot of gauges, it really is worth spending $100 on eBay for a cheap hand held dosimeter, so gauges can be checked as acquired. I don't have a big collection, only twenty or so, and all read about the same as the normal background radiation, ie. virtually no emissions.

 

However, I have one that reads about 450 times normal background radiation directly at the gauge. This gradually decreases with distance until at about two metres, readings are normal. The gauge is unissued, in mint condition with no obvious points where radiation could escape from the radium paint.

 

It's the very common 'Blinker' oxygen flow indicator found on many U.S. aircraft, such as the B-17, P-51 etc..

 

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These were made by different contractors like Delco etc.. It's worth noting that I have another identical Blinker that is part of an MQ-1 oxygen equipment test kit, and it reads normal, no noticeable emmissions.

 

In the case of the radioactive one, if it was on a shelf beside a computer desk where someone spent a lot of time, it would eventually lead to an unhealthy cumulative dose.

 

I think it's quite rare to come across a gauge emitting that much radiation - it seems far too high for the amount of radium paint involved, but it's a good example of why all gauges are worth checking with a cheap geiger counter. People can buy these gauges on eBay and have their kids in contact with them, not knowing what the risks are.

 

With any older gauge, removing the glass or dismantling the gauge for cleaning is also risky business.

 

Cheers, Willie.