Received the following.
Sorry to be a little slow to respond. As far as our range ventilation goes, the entire air in the range is replaced every 70 seconds. There is a gentle breeze of ~~60 fps across the shooters shoulders. It is well heated and cooled when appropriate. I have not had anyone complain about air flow since we did the upgrades. I am confident our customers are happy with our ventilation. Lead poisoning is not at all a concern.
Doug's Shoot'n Sports