Didn't read the article in depth... but... I mean, if you grow veggies to eat within a few feet of your house foundation, yeah there will be "elevated" lead levels in the soil and in your food. If you live near major road ways, in a city, in a old community, your lead levels will be higher. It hasn't been "that" many decades since all the cars ran on leaded fuels and houses were painted with lead based paints. I mean, live downwind of industry and you'll have way more contaminants in the air that just get washed into your gardens, on to your pets, or even floating into your homes than if you lived in a forest. But we all know we can't all live in a forest... if we did they'd just turn into a place like the city!
Unfortunately, lead has pretty much contaminated all the soils in heavily populated areas. If it's not lead in the city, it's emissions, arsenic, or plasticizers. If you're in the country, it's pesticides, solvents, and old houses which haven't had their decades old lead painted homes sanded off into the surrounding environment and are still insulated with asbestos. It's always something that is going to give us cancer, deformities or defects. If they don't give it to us, the stress of stressing will degrade the emotional quality of life.