Mushrooms found growing anywhere near cities or suburbs should also never be consumed, as they specialize in concentrating heavy metals from soils. The most wel

Mushrooms found growing anywhere near cities or suburbs should also never be consumed, as they specialize in concentrating heavy metals from soils. The most well-known example is the radioactive mushrooms of Chernobyl, which end up eaten by wild boars in the region (and boars don't stay in one place): https://www.theverge.com/2017/2/24/14733094/radioactive-pigs-boars-czech-republic-central-europe-germany-chernobyl https://www.theverge.com/2017/2/24/14733094/radioactive-pigs... In cities and suburbs the main problem is likely due to the use of tetraethyl lead additives in gasoline for many decades (~1930s to ~1990s). Downwind of coal plants the mercury and arsenic are more problematic. Add both and some more industry and you end up with heavy metal cocktails that just recirculate endlessly. If you want to grow foods in cities, there is a solution - raised beds that are separate from the underlying dirt, filled with soil trucked in from rural farms that aren't adjacent to industrial pollution sources. Note also that some 'natural environments' have quite a bit of heavy metals and toxic elements, due to natural weathering from geological outcrops, and some plants in these environments accumulate such metals (nickel, arsenic, etc.). If you're concerned, sending a sample of your local soil to a testing lab is relatively inexpensive.