> Now, a cubic meter of soil is a very large amount, so the effective concentration is what actually counts. What counts is how much winds up in humans' bodies

> Now, a cubic meter of soil is a very large amount, so the effective concentration is what actually counts. What counts is how much winds up in humans' bodies. And halfway: how much winds up in crops grown in such areas. There is no 1:1 relation between [concentration in the soil] and [concentration in crops grown in that soil]. Some plants are known to be strong accumulators of certain elements/compounds. And some plants could be low in X even if soil they're from is high in X. So the only way to be sure is have crop samples chemically analyzed.