草莓、蘋果、番茄你真的洗對了嗎?

During their growth period, crops such as fruits and vegetables inevitably encounter pests, diseases, and weeds. To prevent or combat these hazards, farmers often use pesticides such as insecticides and herbicides, which is currently one of the most important control methods. However, if these pesticides remain on the surface of crops and are ingested over a long period, they may have potential health effects on humans.

So, how can we determine which fruits and vegetables have higher pesticide residues and which have relatively lower residues? And how should we wash them to effectively reduce pesticide residues? Are there any authoritative organizations that provide relevant data for consumers to refer to?

The Environmental Working Group (EWG) annually analyzes and ranks pesticide residue levels in 46 common fruits and vegetables based on data from over 46,000 agricultural product samples tested by the U.S. Department of Agriculture (USDA). The EWG publishes two lists: the "Dirty Dozen" and the "Clean Fifteen." This information is also included in the annual "Shopper's Guide to Pesticides in Produce," serving as a reference for consumers when selecting fruits and vegetables.

List of the 12 "Dirtiest" and 15 "Cleanest" Fruits and Vegetables in 2021

According to EWG's latest 2021 Shopping Guide to Pesticide Residues in Agricultural Products, strawberries remain the number one on this year's list of the "12 Dirtiest Fruits and Vegetables." Notably, strawberries have held the top spot for five consecutive years, followed by spinach and kale.

The following are twelve fruits and vegetables with high pesticide residue levels, listed in order according to EWG:

love bite
broccoli
Kaleand mustard greens
nectarine
apple
wines
cherry
peach
梨
Bell peppers and chili peppers
celery
tomato

These fruits and vegetables were generally found to contain a variety of different pesticides, and the residue concentrations were generally higher than those of other fruits and vegetables.

As for fruits and vegetables with relatively low pesticide residues, EWG has also compiled a list of the "15 Cleanest Fruits and Vegetables," which includes:

avocado
sorghum
pineapple
onion
pawpaw
Sweet peas (frozen)
eggplant
asparagus
Broccoli
cabbage
kiwi fruit
Cauliflower
mushroom
melon
Hami melon

EWG pointed out that the pesticide residue situation of these 15 kinds of fruits and vegetables is the most optimistic, especially avocados and sweet corn, with more than 98% of the samples showing no pesticide residue at all.

Are the "12 dirtiest fruits and vegetables" really inedible?

Seeing this ranking, many people may start to worry. The fact that the fruits and vegetables they usually eat are on the list of the "12 dirtiest fruits and vegetables" means that these foods are unsafe and should even be avoided. Should they only choose the items from the "15 cleanest fruits and vegetables" for peace of mind in the future?

In fact, there is no need to panic. EWG's ranking is mainly based on the number of pesticides "detected" in each fruit and vegetable, and the "average residue concentration" regardless of the type of pesticide. Their research shows that about 70% of fruit and vegetable samples can detect at least one pesticide, but the residue concentration of the vast majority of pesticides is far below the safety standards set by the government. Therefore, overall, the fruits and vegetables on the market are still safe to eat.

Professor Chao Ming-wei, a toxicology expert, also stated that, according to the Taiwan Food and Drug Administration's recommendations, washing fruits and vegetables is the most important part of daily diet. The reason is simple: rinsing with clean water is the most direct and easiest method to implement, effectively reducing pesticide residues.

According to data from the Agricultural Pesticides and Toxic Substances Testing Institute, pesticides can currently be broadly classified into two categories: "systemic pesticides" and "contact pesticides." Among them, contact pesticides tend to adhere to the surface of fruits and vegetables, especially on the outer skin or protruding parts, often resulting in higher residual concentrations.

Therefore, as long as these pesticides attached to the surface of fruits and vegetables can be removed as much as possible, the risk of human ingestion can be effectively reduced. It is recommended to soak the fruits and vegetables in clean water for a few minutes before washing to help the pesticides dissolve in the water, and then rinse them continuously with running water for about 15 to 20 minutes to wash away any residual pesticides.

There are specific guidelines for the order of cleaning and cutting to avoid secondary contamination.

In addition, many people may wonder whether they should wash fruits and vegetables before or after cutting them to more effectively reduce the risk of pesticides.

Professor Zhao Mingwei suggests that the correct approach is to wash first and then cut. If you cut before washing, pesticide residue on the surface of the fruits and vegetables may contaminate the knife. Using the same knife to process other clean parts can easily lead to secondary contamination. Therefore, it is recommended to thoroughly rinse fruits and vegetables before cutting or peeling them. Any inedible parts can also be removed beforehand for added safety.

In addition, Zhao Mingwei also reminded that fruits and vegetables should not be washed for too long; moderate washing is sufficient. If soaking or rinsing is prolonged, water-soluble nutrients and minerals in fruits and vegetables may be lost, which is actually detrimental to health.

In summary, while the use of pesticides in the cultivation of fruits and vegetables is difficult to avoid, we don't need to worry excessively. By adopting correct washing habits and choosing appropriate processing methods, we can effectively reduce pesticide residue intake. A balanced diet is the key to truly maintaining good health.