Northeast us. A big distinction is we were built out before most of the country. The land has been settled longer and you’re much more likely to find houses that have been around longer. Even when you find modern houses, they are likely on a lot previously having an older house. So, yeah, lead contamination is more likely than areas with more recent growth

I have absolutely no idea how common lead testing is, but I also know most of the region trends blue, more likely to be aware of potential public health issues and do something about it