Is it safe to eat pesticide-contaminated mushrooms from a grocery store?

What's actually in it

Mushrooms grow in compost and growing substrate that can be treated with fungicides to control competitor fungi. The mushrooms absorb the chemicals through their mycelium. Unlike vegetables, mushrooms don't have a protective skin that rinses clean. Whatever is in the substrate is in the mushroom tissue.

Commercial white button, cremini, and portobello mushrooms are all from the same species, and all grow in similar industrial conditions.

What the research says

A 2026 study in J Agric Food Chem asked directly whether pesticide residues in edible mushrooms pose a health hazard. The study found measurable residues in most commercial samples, with some above recommended limits for regular eaters. The pattern was consistent across brands and countries of origin.

For regular mushroom eaters: organic mushrooms grown without synthetic fungicides are the cleaner mainstream option. Specialty mushrooms like shiitake, oyster, and lion's mane are typically grown on cleaner substrates (logs, straw, sawdust). Wild-foraged mushrooms (with proper identification) come from soils without commercial fungicides. Brushing mushrooms well before cooking removes surface contamination; soaking or deep cleaning doesn't change the internal content.