Information is the key here....
There are many types of Brass, some which contain lead and "could" be argued as being harmful, and some that don't contain any lead whatsoever.
I've used a brass drip tip made of C464 brass, its makeup is 60% copper, 25% zinc, 10% iron, 1% tin.
Even if there was trace lead, the gassing temps are important to understand as well as leaching properties.
Our coils don't come anywhere near the temps needed for brass to gas out.
I do agree that information is important though. And having trust in the maker, like I said above, I know exactly the composite of that brass trip tip I've been using..
You're right we don't know, but lead is one of those things that builds up in your body and slowly poisons. Lead interferes with a variety of body processes and is toxic to many organs and tissues including the heart, bones, intestines, kidneys, and reproductive and nervous systems. It will not affect how the tip looks or how it functions. But is a $30 drip tip worth the added risk?
A lot of us got away from cigs to get away from added chemicals, with that line of thinking we might as well still be smoking.