Eating pesticide-free may mean a diet with fewer strawberries, or at least eating their organic versions.
Strawberries topped the Environmental Working Group's "Dirty Dozen" list of produce with the most pesticides. It's the second straight year strawberries have led the list, which has been published since 2004 and is based on U.S. Department of Agriculture tests of 48 types of produce.
EWG, a non-profit research group, found 70% of the thousands of analyzed samples contained at least some pesticides. Altogether, the group found 178 different types of pesticides.
"Eating plenty of fruits and vegetables is essential no matter how they're grown," said EWG senior analyst Sonya Lunder, "but for the items with the heaviest pesticide loads, we urge shoppers to buy organic."
Just about all the samples of strawberries, spinach, peaches, nectarines, cherries and apples contained pesticide residue, the analysis found. The most contaminated of the strawberries had 20 different pesticide types.
"A crop like strawberries will always have lots of pesticide residues because they are vulnerable to pests, they grow directly in the soil, have a high water content and lack a protective outer peel," Lunder said.
Spinach made one of the more notable jumps on this year's list, moving from No. 8 to No. 2. Lunder said the USDA "found significantly more pesticides by weight than prior years," with the average pesticide weight on spinach doubling that of other produce.
Sweet corn and avocados topped the EWG's Clean Fifteen list of foods with the least amount of pesticides. The study found these foods contained few pesticides and pesticide residue.
The organic produce market has exploded since the 1990s. A market analysis by the Organic Trade Organization found organic food sales increased from $3.6 billion in 1997 to $43.3 billion in 2015, with no signs of slowing down. Millenials, the study said, have stoked organic growth along with more consumer interest in where food comes from.
"From the surge in sales of organic food year after year," Lunder said, "it's clear that consumers would rather eat fruits and vegetables grown without synthetic pesticides."
A recent USA TODAY analysis on washing produce, showed regulations, and the level of pesticides on produce, make it unlikely a person would get sick from eating raw produce. Although it's not impossible.
The Alliance for Food and Farming, which represents organic and non-organic growers, is opposed to the EWG's list. The alliance's Executive Director Teresa Thorne said the list has been "discredited" and dissuades people from eating fruits and vegetables.
"If EWG truly cares about public health," Thorne said, "it will stop referring to popular produce items that kids love as 'dirty' and move toward positive, science based information that reassures consumers and promotes consumption."
However, the EWG said parents, in particular, should avoid feeding their young children food with pesticides, which have been linked to lower IQs.
"Even low levels of pesticide exposure can be harmful to infants, babies and young children, so when possible, parents and caregivers should take steps to lower children's exposures to pesticides while still feeding them diets rich in healthy fruits and vegetables," said Dr. Phillip Landrigan of the Mt. Sinai School of Medicine in New York.
EWG's Dirty Dozen includes: strawberries, spinach, nectarines, apples, peaches, pears, cherries, grapes, celery, tomatoes, sweet bell peppers and potatoes.
The Clean Fifteen includes: sweet corn, avocados, pineapples, cabbage, onions, frozen sweet peas, papayas, asparagus, mangoes, eggplant, honeydew melon, kiwi, cantaloupe, cauliflower and grapefruit.