The Environmental Working Group has named these as the most recent list of Dirty Dozen and Clean 15: (wellnessmama.com)
Spinach is one of the EWG's Dirty dozen as well so buy organic! (ruthyaron.com)
To help determine whether or not to purchase organic, use the EWG dirty dozen list which evaluates produce that is the most or least laden with pesticide residue. (crunchyradish.com)