10M air pistol? FWB, Steyr, Walther, ...

I'm well past child-rearing age and my nieces and nephews are all either graduating high school in a couple of weeks or are adults with their own children.

In terms of lead exposure, I've been down that road with gun ranges and shooting smallbore during college. While a valid concern, living on a farm I'm more concerned with exposure to pesticides and herbicides personally in this old drafty farmhouse. Skin cancer from sun exposure is more likely to kill me than lead dust at this point but, your point is understood and prudent advice for anyone, myself included.

I have a 22lr trap with sand in the tray to catch bullets off the 45-degree backstop. With a cardboard target face, most dust will be limited to the inside of the trap and the sand trap in the bottom. Lead splatter will be reduced too by running ~500 FPS so, putty, clay, or appropriate cardboard are all pretty good option to cut dust and richochets.
My first and only factory job was making the last of American billiard balls. One facet of the junior guy was cleaning the still warm 10 foot square ovens. I’d say I sucked in a cities share of phenols, formaldehydes and dozens of other chemicals.
Next came pumping gas which could take a turn to gasoline siphon sucker from non paying customers. Cleaning asbestos
encased huge boilers as a coal handler in a power plant. This all before my dream job as a lineman. Then it was only the Aluminum accumulating in your brain leading to Alzheimer’s possibilities . Not concerned with lead either.

ps. Yes this strayed off topic but carried on long enough don’t all…
Shooting indoors is fun, at least if you are alone and not irritating people who can hear it. The danger, with any lead, is the dust from impact so putty traps are best and for heavens sake don't let toddlers crawl around that area or suck on lead pellets (they taste salty).