If I can’t wash the pesticides away, can I cook them out?
Sure, sometimes cooking can nuke the potentially harmful pesticides, but to use apples as an example again, neonicotinoids -- used as fungicide to keep apples fungus-free while in cold storage -- are heat-resistant. It’s all, basically, a mess.
Some plants naturally have some pretty powerful anti-pest protections, which can also be the reason we like them. Onions and chile peppers, for example: Their pungent flavor is actually meant to keep bugs away, so not all that much pesticide is needed for them. Feel free to buy non-organic onions.
But it takes an awful lot of knowledge to know which plants have built-in pest protection, so in general, it makes sense to follow the EWG’s guide for produce. You don’t want to bother scouring individual items for the dangers of pesticides. EWG’s lists are helpful and clear. In general, EWG recommends buying organic whenever possible. “If you're worried about budget, prioritize the stuff on the Dirty Dozen list,” says Lunder.