[ip26]

It isn’t always a modern affliction. Some food plants just do this, pulling heavy metals from the soil. You’ve heard of arsenic in brown rice.

[ars]

So about that... a portion of the arsenic in the Southern US is from old pesticides used on cotton!

The only good news about that is levels are constantly dropped as it gets "used up".

However this is only a portion, in many places arsenic is just there in the ground.