[akiselev]

According to [1], "the normal concentration of uranium in soil is 300 μg/kg to 11.7 mg/kg." According to [2], the density of topsoil ranges from 1,100 to 2,500 kg/m^3. One acre is about 4,000 m^2, so a conservative estimate is that there is about 1.3 kg of uranium in 1 meter of top soil on a 1 acre lot. (4000 m^3 * 1100 kg/m^3 * 3x10^-7). That's just the low end - taking the midway point for both yields over 40kg (4000 m^3 * 1800 kg/m^3 * 6 mg/kg).

[1] https://en.wikipedia.org/wiki/Uranium_in_the_environment

[2] https://structx.com/Soil_Properties_002.html

[masonic]

  on a 1 acre lot

Not many of us have all of an acre lot for our homes.

[akiselev]

According to [1], 2 billion people are subsistence farmers with under 5 hectares. The population adjusted average seems to be around a quarter of a hectare (~0.6 acres) per person (which sounds low to me, as someone who has grown my own food without automation).

10^9 == many of us. Unless your definition of "us" is hacker news readers.

[1] https://en.wikipedia.org/wiki/Subsistence_agriculture