“In terms of washing, it should remove some residues on the skin of a product (which will often be fungicides used to prevent rotting during storage and transportation). However, many modern pesticides are what are called ‘systemic’ which means that they are absorbed into the plant and distributed throughout its tissues, reaching any fruits or flowers. As a result, pesticide residues are often contained within the body of the produce itself and therefore washing the surface won’t remove them.”