This was brought up years ago by .gov studies and it forced a retro fit of their facilities to update the ventilation, etc. The local college got massive air movers and the air intake on a cold winter day can overpower the heating system. Gets nippy
It could be said that much of the risk comes from .22 and handloaders - the tactical practical shooters buying store bought jacketed ammo aren't splattering wheel weights off the steel plate downrange, those rounds tend to hang together a lot more.
As for going all copper or non lead being a "power reducer" that hurts downrange performance, I suppose Barnes Bullets is just hanging on by the skin of their teeth from poor market penetration 'cause we all know it takes a chunk of lead ta kill somethin'. Explains the huge comeback in ducks and geese being a nuisance nationwide, too.
Not. There is less lead in ammo now than ever before.
The local paper had a full page spread on it, listing "victims" of lead poisoning and the horrible effects from absorbing a toxic load. The problem is that very few facilities are actually inspected unless there is a blood test report saying someone was contaminated. And, if you work at a range, you are likely a shooter, might reload, and the source of your contamination hasn't been specifically pinpointed.
Much like the research on lead poisoning of ducks, there is a lot of speculation and NO hard science or explanation in parts per million. What constitutes "severe?" We don't know. And it doesn't help that ranges in gun hater communities are the ones made into poster child examples of enforcement - like one in the suburbs of Chicago, aka Obamaville.
Just another anti gun attack story for the agenda masters, but the real point is that we should be aware. It could happen, yes, is it severe problem? I was raised in a lead mining community that spreads over a 50 mile radius, where any building older than 1970 was likely painted with lead paint, and older plumbing drains were likely caulked with lead. We still use lead weights on car wheels, they fall off on the roads by the thousands and are ground up on the pavement or sit on the side of the road. Those are shipped in folded cardboard boxes with no shrink wrap to contain the dust. Same with porous fabric bags of lead shot. I used to work at a factory that would be filled with smoke from welding a known toxic source, galvanized sheet metal. After years of use, managment finally installed fume collecting welding nozzles - so we woudn't have to breathe it.
Live in a sniff test auto pollution controlled municipality? Your air there is so contaminated from exhaust they instituted that inspection procedure, so that is the air that gets sucked into the expensive range ductwork to "protect" you from lead dust.
Don't lose perspective on it.