When I worked in the chemical industry we were always looking at comparative exposure case studies to make sure what we did was safe. A process required opening and unloading a lead-based raw material so we looked to lead mining as the worst possible exposure and what safety precautions they took and corresponding illness rate.
It turned out that lead miners had slightly higher lead levels in blood and tissue but no more than someone living in a house containing lead paint, over coated with led-free latex paint. Also, lung diseases were typically caused by exhaust fumes or silicate/asbestos exposure.
I think you perhaps choose poorly?, lead smelting and lead recycling are probably far worse than the actual mining.
I grew up in a lead mining area, and one of the most successful lead mines in the world was the other side of the hill (Millclose Mine) - but has been a lead smelter and recycler since around the end of WW2. They had to plant large plantations of trees where ever they could in the surrounding countryside, apparently trees help to reduce lead pollution, and have special monitors installed throughout these woods and the general area, that monitor lead levels.
They also had to provide free milk for all children of school age, apparently milk helps protect against lead contamination - my wife lived in the area, and she received free milk as a child.
As far as I'm aware the free milk stopped a number of years ago, and they only recycle car batteries etc. these days, and presumably emissions are far more tightly controlled. The woods and the monitors are still in place though.
As an ex-caver, I've been in plenty of old lead mines, and the whole surrounding area is littered with lead mines, many of which have long since been lost. So how do you 'seal' a mine shaft - you stick a couple of planks of wood across the top. Over the years grass grows over the top, and the location of the shaft is lost - I think you can all see where this is going
- over the decades the wood rots away, leaving a thin layer of grass over the top of the shaft
There are literally thousands of such lost mine shafts on the area, which is why there are frequent signs warning you to stick to the paths, and don't wander away from them.
There are also a number of local places called 'Bole Hill', and these refer to lead smelting - where they dug a depression in the top of a hill, and you piled lead ore and fuel in a heap in the depression, and set fire to it. I suspect the level of pollution from that would be rather high?.
Another lower level version is to build a 'chimney' up a hillside - there are many not far from where I grew up, near the River Lathkill - essentially it's a stone built long dome structure running up the hill side, with a big fireplace at the bottom, You pile up the ore and fuel, set fire to it, and as the smoke goes up the 'chimney' lead which would normally be lost in the smoke is deposited on the walls and roof - and every so often you send people up to brush it off and recover it. I presume that's a more 'modern' version of the 'Bole Hill' type of smelting.
Obviously this was all long ago - but I wouldn't be surprised of they weren't still some horrific practices in various third world countries.