[Gordonjcp]

The CDC believes a lot of fairly bonkers stuff that does not match up to reality.

If you heated solder up to the point that lead was boiling off, your circuit board would be on fire.

You cannot get lead poisoning from using leaded solder.

[AlgorithmicTime]

I mean if you start licking it or chewing it you might, but normal usage just wash your hands afterward and you're fine.

[Gordonjcp]

You'd have to eat a lot of solder. Metallic lead reacts with fuck all, basically, which is why it's such a good material for things like roof flashing. It doesn't even react particularly with the hydrochloric acid in your stomach, producing only lead chloride (which will make its way out of your body fairly quickly) and hydrogen gas (not enough to do anything fun if you burp while smoking a cigarette, but let's not take chances eh). Metallic lead is about as bioavailable as sand.

No no, if you want to get lead into your system you've got to really try quite hard. Taking some lead and mixing it with tin won't get the job done, oh no, not even a little bit. You're going to want to make it into an organic salt, maybe by welding on a lovely big acetate and then getting that into your stomach.

Now why would you want to do a thing like that?

Well, you might be an ancient Roman, with a fondness for "defrutum", a sweet sticky confection made by boiling soured wine and grapes in a lead pot until all the water is driven off. The acetic acid rips lead out like nobody's business and gets well and truly stuck together. Oh, and it tastes really sweet too, this lead acetate, which is just the thing to liven up any Roman party if the wine's gone a bit funny in the sun.

Now you've got a lovely big sugar that your digestive system will happily squish into your sensitive tissues, where it'll break up and be on its way leaving a big fat lead atom right there with nothing to bind to, until it finds something. Oh hey, you know that sugars - even with a great big lead atom weighing them down - cross the blood-brain barrier just fine, right? You couldn't design a better way to get lead poisoning.

Now toss in some ergot mould because you won't eat the local wheat because everyone is going mad from something and it must be those wily locals poisoning you so you only eat rye shipped over from Rome in mouldy sacks, and pretty soon - between the brain damage from lead acetate and the hallucinogenic mould - you're ready to turn horses into senators, and tell your soldiers to blunder into midgie-infested marshes in the North of Scotland where they sink out of sight never to be seen again.

Lovely.