Popular morning snack and dinner staple found to contain alarming levels of autism-linked chemicals

People vying to be healthy may want to think twice before reaching for two popular nutritious staples.  

The Environmental Working Group, a health advocacy organization, recently released its ‘Dirty Dozen 2025’ list – where it ranked the fruits and vegetables covered in the most toxic chemicals.

After analyzing the Department of Agriculture’s data on levels of pesticide contamination in different fruits and vegetables, the group ranked 47 of them based on their toxicity levels. 

Of these, they found the top 12 fruits and vegetables covered in pesticides. 

While usual suspects such as spinach, strawberries and kale took the top three spots, researchers noted that blackberries were a new addition to the list. 

Over 80 percent of samples of the popular berry, which is usually priced at $6 for 12oz, were found to be covered in two or more pesticides, placing it 10th on the list. 

The agency noted the most common pesticide they found on blackberries was cypermethrin – a toxic synthetic insecticide linked to autism. 

Also new on the list, landing in 12th place, were potatoes – the most commonly eaten vegetable in the US.

The researchers found nearly all of the 1,000 samples of potatoes had high concentrations of chlorpropham, a plant growth regulator banned in the European Union due to its hormone-disrupting and cancer-causing properties. 

The Environmental Working Group, a health advocacy organization, recently released their ‘Dirty Dozen 2025’ list

Alexis Temkin, EWG’s Vice President of Science told CNN: ‘The guide is there to help consumers eat a lot of fruits and vegetables while trying to reduce pesticide exposure. 

‘One of the things that a lot of peer-reviewed studies have shown over and over again (is) that when people switch to an organic diet from a conventional diet, you can really see measurable levels in the reduction of pesticide levels in the urine.’

Organic produce is grown without synthetic pesticides, with farmers opting for more natural options that are less persistent in the environment. 

Alexis Temkin, EWG’s Vice President of Science

She noted that her team found 50 different pesticides across a variety of fruits and vegetables that made the Dirty Dozen list. 

Coming in fourth were grapes, fifth were peaches and sixth were cherries. 

These fruits were followed by nectarines, pears and apples at seventh, eighth and ninth place, respectively. 

The EWG ranked blueberries in 11th place.

The agency noted blackberries had never made it on the list before as they hadn’t been tested prior to 2023. 

However, both the EWG and Department of Agriculture examined 294 non-organic blackberry samples from July through December 2023 and found at least one pesticide in 93 percent of them. 

Most notably, they discovered the presence of cypermethrin, which is banned in the EU to due to its dangers to human health.    

Over 80 percent of samples of the blackberries, which is usually priced at $6 for 12oz, were found to contain two or more pesticides and was ranked tenth in the list

While cypermethrin has proven beneficial in killing harmful insects in berries, certain studies have shown that consumption by pregnant woman may increase the risk of autism.

A 2019 BMJ study found that a baby had a higher risk of developing autism if its mother had been exposed to cypermethrin within 6,500 feet of their home during her pregnancy. 

Cypermethrin has also been found to disrupt thyroid hormones, which are critical to brain development. 

At times, direct exposure to the insecticide may also cause irritation to the skin and eyes, numbness, tingling, itching, a burning sensation, loss of bladder control, incoordination, seizures and in severe cases, death. 

Since fruits such as blackberries are promoted for being rich in antioxidants and vitamins, they are often included in recommended healthy diets for children and pregnant women to help improve their nutrition levels.

However, this may put them at a higher risk of being exposed to the insecticide.

At times, direct exposure to the insecticide may also cause irritation to the skin and eyes, numbness, tingling, itching, a burning sensation, loss of bladder control, incoordination, seizures and in severe cases, death. 

While insecticides are added into blackberry fruits as they grow, potatoes are covered in pesticides after they are harvested and ready to eat. 

Temkin said: ‘It’s applied after harvest to essentially prevent potatoes from sprouting while they’re in storage or in transit. 

‘Because it’s applied so late after harvest and so close to when consumers might be exposed or eating potatoes, that’s partially what leads to some of these really high concentrations.’

Between 2022 to 2023, the Department of Agriculture collected and tested more than 1,000 samples of potatoes for pesticides after washing and scrubbing each piece. 

They found that over 90 percent of samples contained twice the acceptable levels of chlorpropham allowed by the Environmental Protection Agency even after washing and scrubbing. 

The toxic pesticide has been linked to causing changes in blood cells and harm to the thyroid by reducing the production of certain hormones such as thyroxine – which is responsible to maintain the growth of cells. 

Low levels of thyroxine can cause DNA mutations and excessive growth of cells across the body – which may pave the way for cancer development. 

Similarly to cypermethrin, a 2024 Medicina study also found that prenatal exposure to chlorpropham has been found to increase a baby’s risk of developing autism. 

Nearly all of the 1,000 samples of potatoes had high concentrations of chlorpropham, a plant growth regulator 

Chlorpropham was banned in the EU in 2019 after officials found that people, particularly children, were being exposed to more than acceptable levels of chlorpropham through non-organic potatoes. 

Despite the results, Temkin noted the annual report is not meant to discourage consumers from eating fruits and vegetables but instead to encourage people to buy organic food. 

Multiple studies have shown that those who consume organic food have lower exposure to synthetic pesticides as organic farming prohibits the use of such chemicals. 

The EWG recommends buying organic whenever accessible because food residues are a main source of pesticide exposures for many people. 

For people looking to eat cleaner fruits and vegetables, the EWG found pineapple to be the least contaminated produce tested, followed by sweet corn (fresh and frozen), avocados, papaya, onions, frozen sweet peas, asparagus, cabbage, watermelon, cauliflower, bananas, mangos, carrots, mushrooms and kiwi.

If you do opt for a dirty dozen, be sure to wash it with water or solutions of baking soda or vinegar.