We get it—organic foods often cost more than their nonorganic counterparts. That's especially true when it comes to fresh produce. If you're on a tight grocery budget but prefer to buy organic fruits and veggies, allocate your budget for the 12 items on the 2020 Dirty Dozen list from the Environmental Working Group. EWG uses data from organic and nonorganic produce testing by the U.S. Department of Agriculture, which screens more than 43,000 samples of 47 different fruits and vegetables to detect impurities. According to the study, these fresh produce items are the most likely to contain pesticides and insecticides when you choose the nonorganic, conventionally grown variety.

Apples

Because apples have a thin peel, their flesh absorbs the pesticides used on trees. EWG detected this issue in 90% of nonorganic apples tested, finding that 80% of the samples contained the Europe-banned pesticide diphenylamine.

Celery

If celery with peanut butter or ranch is your favorite healthy snack, buy organic. Over 95% of the EWG samples of nonorganic celery contained pesticides, including up to 13 different contaminants on a single sample.

Cherries

Most cherries tested by EWG contained about five different pesticides. In addition, 33% of the samples contained DCPA, a cancer-causing substance banned in Europe.

Grapes

Go organic for grapes, which contained up to five different pesticides in the 2020 Dirty Dozen study. In fact, contaminants were found in 96% of the tested nonorganic grapes.

Kale

Kale was new to the Dirty Dozen list in 2019 after more than a decade of testing clean in EWG studies. In 2020, at least 92% of kale samples contained at least two pesticides, and some samples contained up to 18 contaminants. In addition, carcinogenic DCPA showed up in 60% of the tested samples.

Nectarines

Nonorganic nectarines are a no-no if you're concerned about pesticides. More than 94% of the EWG samples contained at least two pesticides, with up to 15 contaminants found in some shipments of this summer fruit.

Peaches

Almost all the peach samples studied by EWG—99%—showed pesticide contamination. Most of the samples had about four different types of pesticide residue.

Pears

Insecticides, pesticides and fungicides were all detected in nonorganic pears. In fact, more than 50% of tested samples included at least five different contaminants.

Potatoes

Potatoes grown with conventional methods contain the highest amount of pesticides by weight than any other produce tested by EWG. Most of the potato samples contained a noted neurotoxin.

Spinach

EWG found that nonorganic spinach tested contained more pesticides per pound than any other veggie in the study. The tests revealed significant levels of permethrin, which has neurotoxic qualities.

Strawberries

If you love strawberries in your morning cereal or as a sweet afternoon snack, buy organic. EWG found that 90% of nonorganic strawberries tested contained two or more pesticides.

Tomatoes

Some of the nonorganic tomatoes tested by EWG contained more than 15 different contaminants. On average, the conventional tomatoes in the study contained at least four pesticides.

While you might have to splurge to go organic for these 12 items, EWG also compiles an annual list of The Clean 15. At least 70% of the nonorganic samples on the 2020 Clean 15 were contaminant-free, including asparagus, avocados, broccoli, cabbage, cantaloupe, cauliflower, eggplant, honeydew melon, kiwi, mushrooms, onions, papayas, peas, pineapples and sweet corn.

If you try to avoid pesticides and insecticides on a budget, frozen or canned organic vegetables are a savvy choice for smart shoppers. Since the Dirty Dozen list started in 1993, groups like the American Academy of Pediatrics have credited EWG with the reduction of potentially harmful dietary pesticide exposure in the U.S. When you do choose fresh, you should always wash produce completely before consuming.