Kale and Pesticide Residues

According to the Environmental Working Group (EWG) in their 2014 report, Shoppers Guide to Pesticides in Produce, conventionally grown kale are contaminated with concentrations of organophosphate insecticides, which are considered to be highly toxic to the nervous system. While they were not among the 12 varieties of produce most concentrated in overall pesticide residues (and therefore not part of the EWGs traditional Dirty Dozen), the EWG felt that this organophosphate concentration was relevant enough to bring attention to kale. They actually renamed their produce category of concern from Dirty Dozen to Dirty Dozen Plus with kale, collard greens, and hot peppers being the Plus conventionally grown produce. Therefore, individuals wanting to avoid pesticide associated health risks may want to avoid consumption of kale unless it is grown organically.