Toxic chemicals linked to infertility found in Big Macs and Taco Bell burritos

• Researchers tested burgers, burritos, and pizza from six of the top fast food chains in the US for various chemicals.
• They found chemicals that have been linked to reproductive problems in more than 80% of the samples.

Most Americans know that fast food is not good for their health, especially since films like "Super Size Me" and "Food Inc" took a critical look at the industry in the early aughts.

But consumers may not realize that they could be getting a side of chemicals along with the sugar, salt, and trans fats in their fast food meals, Lariah Edwards, a postdoctoral scientist at George Washington University, told Insider.

In a recent study, Edwards and colleagues ordered from six of the most popular fast food chains in the US - McDonald's, Burger King, Pizza Hut, Domino's, Taco Bell, and Chipotle - and tested samples of the food for 11 plasticizing chemicals.

They ordered the most popular meal at each restaurant with the typical fixings: hamburgers, chicken nuggets, and fries at the burger joints; burritos loaded with chicken, rice, beans, salsa, and more at the Tex-Mex chains; and a couple plain cheese pies from the pizza places. Generally, foods containing meats had higher levels of chemicals.

More than 80% of samples contained known phthalates, a class of chemicals used to make plastic softer and more flexible. Phthalates and other plasticizers are commonly found in food packaging and gloves, despite their known effects on human health.

Past studies have found people who reported eating more fast foods had higher levels of phthalates in their urine, but this is the first effort to test the food itself with a new generation of plasticizers in mind.

Phthalates have been linked to reproductive problems and early death

Several phthalates have been found to interfere with hormone function, which can lead to a cascade of problems with fertility and child development.

People with high levels of phthalates in their urine were also found to be more likely to die early, especially due to heart disease, in a recent study.

While one Big Mac probably won't kill you, it's important to consider your phthalates exposure overall, Edwards said. Exposures in food can build on other sources of chemicals, like cosmetics and cleaning products.

"While they don't build up in your body the way that PFAS chemicals do, you still are being constantly exposed to these phthalates from multiple sources," Edwards told Insider.

Since the chemicals have been linked to adverse health effects, the Consumer Product Safety Commission banned the use of eight phthalates in children's toys and child-care articles in 2017. However, those banned substances are still used in other plastics, and at least four of them were detected in fast foods.

The researchers also tested for a new plasticizer called DEHT, which is used to replace banned phthalates, and found it in 86% of the food tested. Replacement plasticizers like DEHT are not yet well-studied for possible health effects, but the GW team found they "behaved similarly" to ortho-phthalates in terms of acting on hormone receptors.

Racial residential segregation means Black people may be especially at risk for phthalate exposures

The study authors noted that certain racial and ethnic groups are more likely to eat fast food than others because of many factors, including a history of racial residential segregation. Predominantly Black neighborhoods tend to have a higher density of fast food restaurants, and less access to affordable fresh food, Edwards said.

Because Black Americans consume more fast food than any other racial group, they may be exposed to higher levels of phthalates and other chemicals. Black women have also been found to have elevated levels of some phthalates and parabens in their urine because the chemicals are used in their hair products, although they're often left off the labels.

Given the lack of transparency around these chemicals, the impetus really falls on regulators to keep phthalates out of food and personal care products, the authors concluded.

"Maybe you want to eat less fast food, but that's not always an option for everybody," Edwards said. "Fast food is a convenient alternative to having to cook at home, so it should be not full of chemicals."

The restaurants included in the study did not immediately respond to Insider's requests for comment.