[occupation hazards associated to manufacturing practices from the past. QUOTE]
Yes, partially because of the way the old timers figured things out, the rules, and well just because.
Old style weld rod was nasty, solder and flux were nasty, and some of the coolant is still nasty.
Todays stuff isn't as bad, but anytime you weld say nasty steel, with the rust preventative still on it, oil, think about what that does. how many parts per million of oil in your lungs does it take to drop you?
There are no more or less risks with welding than there is with anything else, driving , sex, fast food all these thing can kill you just as easily, it all part of the game, you just have to use your head.