Thank you for your helpful and thoughtful reply!

Potatoes and spinach are two of my dietary staples, so it is alarming to see them on the "dirty dozen" list.

Would scrubbing, washing, peeling, cooking, etc do something to the "pesticide residue" found on these vegetables?

Occupational exposure is real and serious, and shows what might happen with chronic exposure. There are documentaries and videos that show the hands of field workers in California. They bubble and peel and blister and discolor, all from pesticides.