In South King County and Pierce County, WA (south of Seattle), the basic advice is to not grow any food directly in the ground without having your soil tested first for arsenic. There was a copper smelter in Tacoma for decades, and now everything basically within a 20 mile radius is contaminated.

https://ecology.wa.gov/Spills-Cleanup/Contamination-cleanup/...

https://apps.ecology.wa.gov/dirtalert/?lat=47.349229&lon=-12... (not exactly a circle due to the topography and wind patterns of the area)

The point is, there was a lot of nasty industrial activity in this country pre Clean Air Act. Everyone should be concerned and get their property tested IMO, especially if you have kids. I'm not trying to be alarmist; it doesn't affect my day to day life, it's just something to know. I still grow veggies in my garden, I just use raised beds and dirt from bags from Home Depot.

And decades of paint chips from previous exterior paint prep that may not have been well-contained.

I grew up on a farm where the property has since been divided up and houses built. I remember how my parents were about gasoline for washing paint brushes and old motor oil for painting fences and burning plastics and electronics in the burn barrel. Who knows what happened to pesticide containers. There was a stack of lead pipes I played with occasionally. No idea what pipes were in the house, but it was old, so.

And I totally wonder whether people are growing food there, soaking all of that up.

I found that my backyard soil has very low lead levels from the UMass Soil & Plant Nutrient Testing Laboratory. You can test your soil lead levels, along with nutrient contents of your soil as it pertains to the types of plants you have by sending a sample and $20 to UMass: https://ag.umass.edu/services/soil-plant-nutrient-testing-la...

I just found that the University of New Hampshire offers a similar test with an additional heavy metals package available which covers cadmium, chromium, copper, lead, nickel & zinc: https://extension.unh.edu/resource/soil-testing-forms

UK suburban soil can also be bad as people used to throw fireplace ashes in their gardens, which can concentrate contaminants. I ate from my home allotment for years until a neighbour told me he had recently tested his soil and found it heavy with lead and other rubbish.