The indoor range I'm a member of has very good ventilation. Vertical PVC pipes between each lane blowing fresh air from outside, even heated during the winter. And two large exhaust fans down range. If you pay attention, you can feel the air movement going away from you. That, and I usually shoot early mornings such as 6:00am to 7:00am and 95% of the time I'm the only person there.
But, there's always "that guy". I was at this range on an afternoon. All lanes where full. For what ever reason, one guy suddenly decided he was going to sweep the floor, six lanes wide by 25 yards long. He used a regular push broom, and demanded that the ventilation system was off. The dust (lead dust I'm sure) he was churning up from the floor looked bad. Needless to say, I quickly packed up and left. I did mention something to him about breathing all that lead dust from the floor, he basically told me to shut up and mind my own business. Okay, you're the one with elevated lead levels, not me.
Common sense goes a long ways. Good ventilation, wash your hands and blow your nose after shooting, I think for the most part, everything will be fine.