A group of common chemicals may be tied to language delays in children when women are exposed to them during pregnancy, a study shows. The chemicals are ubiquitous and are found in personal care products, food processing and packaging, toys, and other household items. 
The group of chemicals in question are called phthalates and their other dangers include:
- Atherosclerosis (plaque buildup in the arteries)
- Childhood obesity
- Miscarriages and infertility
- Asthma, allergies, and neurological problems in children
- Early puberty in girls
Study author Shanna Swan, a professor in the Department of Environmental Medicine and Public Health at Moun Sinai Icahn School of Medicine, explained:
“Phthalates are known to be hormonally active and affect the body’s hormone system.”
Double the Risk of Language Delays?!
In the study, high prenatal phthalate exposure was shown to double the risk of language delays in children, according to Swan. 
Swan and her team looked at 963 children and mothers from Sweden and 370 mothers and children in the U.S. to find out how exposure to the group of chemicals during pregnancy might affect language development in kids.
The Swedish subjects were taking part in the Swedish Environmental Longitudinal Mother and Child, Asthma and Allergy Study (SELMA). The subjects in the U.S. were participating in the Infant Development and the Environment Study (TIDES).
The researchers collected urine samples from the mothers in their first trimester of pregnancy and tested them for the presence of phthalates. The parents also completed a questionnaire concerning their child’s language development at 30 months old in Sweden and when they were at least 2 years old in the U.S.
The children were divided into groups based on their vocabulary responses: fewer than 25, 25 to 50, and more than 50 words. A child was considered to have a language delay if he or she had a vocabulary of fewer than 50 words.
The study found that 10% of both populations (96 of the SELMA children and 37 of the TIDES children) had language delays. Among the children in Sweden, 26 had a vocabulary of 25 words or less. In the U.S., that number was 10.
The authors placed the blame for the language delays on 2 particular phthalates.
“There are 2 bad actors in this study, dibutyl phthalate, and butyl benzyl phthalate.”
Dibutyl phthalates are found in some personal care products, while butyl benzyl phthalates are used in products such as vinyl tiles.
Previous studies have shown that both chemicals lower testosterone in mothers during early pregnancy, according to Swan. This helps to explain how they can impact intellectual development. 
Also, Swan noted, both chemicals have been linked in studies to developmental delays, lower IQ, and underdeveloped male sex organs.
She said: 
“We noticed in both populations, and this is not a new finding, that language delay was more common in boys than in girls, and that’s well known.”
The findings remained “very consistent,” even after Swan and her colleagues controlled for factors such as the age of the child, and the age and education level of the mother.
“It’s very unusual to have 2 populations on other sides of the pond, if you will, and very similar response to shared chemicals. These chemicals are in Europe and the United States and they seem to be affecting the children similarly. So, there’s a generalizability here that’s important.”
While dibutyl phthalate and butyl benzyl have been banned in many products, exposure to them is still quite common. Both have been used in vinyl flooring, and since vinyl flooring can be used for decades, people may be exposed to dibutyl phthalate and butyl benzyl for long periods of time. 
Furthermore, phthalates are often found in indoor air, dust, food, and water because they leach into the air.
What’s more, replacements for the phthalates that have been banned simply aren’t much safer.
“Manufacturers have taken out the worst offenders and put in a slight change, which changes its name, but they are equally hormonally active. There have been some substitutions.”
The answer to the problem is for governments to ban phthalates outright, said Steven Gilbert, director of the Institute of Neurotoxicology and Neurological Disorders, in Seattle.
“What we need to do is change the laws. We’ve shown that these are bad actors and they cause cell changes, and we just need to stop using them.”
The study appears in JAMA Pediatrics.