Common Group of Chemicals May Be Associated with Language Delay in Kids
These chemicals, called phthalates, are practically ubiquitous in American households
Phthalates are a common type of chemical found in many household products, including some types of plastic, personal care products, household cleaners, and more.
According to a new studyTrusted Source published in JAMA Pediatrics, prenatal exposure to certain types of phthalates might put children at increased risk of delayed language development.
“This study has a large number of participants, and addresses an important question of whether a mother’s exposure to phthalates in pregnancy is associated with language delay in the child,” Kelly Ferguson, PhD, MPH, a scientist from the National Institute of Environmental Health Sciences who was not involved in the study, told Healthline.
“There are a number of studies that examine a mother’s exposure to phthalates and neurodevelopment in children, but this is the first using this outcome,” she added.
The study was a collaborative project undertaken by researchers at the Icahn School of Medicine at Mount Sinai in New York and Karlstad University in Sweden.
Researchers from each site collected samples of urine from 370 pregnant women and their children in the United States and 963 pregnant women and their children in Sweden.
After those women had given birth, the researchers gathered information about their children’s development of language.
Children who understood fewer than 50 words by the time they were 30- to 37-months old were classified with language delay.
Across both populations, language delay affected 10 percent of children.
Children who were born to mothers with high levels of dibutyl phthalate (DBP) and butyl benzyl phthalate (BBP) in their urine were up to 30 percent more likely to experience language delay, compared to those born to mothers with lower levels of DBP and BBP.
The investigators found similar findings in both the American and Swedish populations. According to Ferguson, that “gives us more confidence in the results.”
Growing body of research on potential harms
This study adds to a growing but inconclusive body of research that suggests that phthalate exposure might raise the risk of certain health problems in children.
“They’re not always consistent, but some studies do suggest that prenatal exposure to some of these phthalates is associated with decreased IQ, as well as changes in behavior,” Joseph Braun, PhD, an assistant professor of epidemiology at the School of Public Health at Brown University, told Healthline.
“There’s been some suggestion that prenatal exposure may also be associated with obesity or changes in later-life metabolism — so risk of things like high cholesterol or insulin resistance,” he added.
Some research suggests that male children who are born to mothers with high levels of exposure to certain phthalates are more likely than others to have undescended testicles.
A potential link has also been identified between childhood exposure to phthalates and the development of allergic diseases, such as food allergy, eczema, and asthma.
Research findings on the potential links between phthalate exposure and negative health outcomes are in many cases inconsistent — and more research is needed to study the potential effects of different phthalates on human health.
Phthalates are all around us
Pregnant women, children, and others come into contact with phthalates in many ways.
For example, three common routes of phthalate exposure include dust, food, and personal care products.
“They’re in carpet backings, and in plastics, and in furnishings, and they’re not bound to those products, so they get into the dust and settle on the carpet,” Braun explained.
“Kids, like my 7-month-old, love to play around on the carpet and put their hands in their mouths,” he added. “So they’re ingesting a lot of dust, relative to their body weight, and this can increase their exposure to many of those dust-borne chemicals.”
Phthalates can also leach into food from the plastic containers in which it’s been packaged, or the equipment with which it’s been processed.
Phthalates are also intentionally added to some types of scented lotion, cologne, and other personal care products.
“Infants that have certain personal care products applied to them have much higher urinary phthalate levels than infants who don’t have those products applied to them,” Braun said, “and we’ve seen the same in pregnant women.”
Limiting exposure is difficult
Because phthalates are so pervasive, it can be challenging to avoid them.
“I tell my friends who are pregnant to do what they can to avoid or at least limit their exposure to phthalates,” Ferguson said.
“But I also tell them that they shouldn’t stress too much,” she added.
To people who want to limit their exposure to phthalates in dust, Braun suggested using a HEPA-filter vacuum to clean carpets, and a wet mop to clean floors.
Limiting your consumption of processed foods may also cut down on the quantities of phthalates that enter your body, he said.
Avoiding personal care products that contain phthalates may also help. The Environmental Working Group’s Skin Deep Cosmetics Database provides a resource that consumers can use to learn if a product contains phthalates.
The U.S. Consumer Product Safety Commission has also implemented regulations that limit the types of phthalates that manufacturers can add to certain products.
But the mechanisms for regulating phthalates and other chemicals in the United States are reactive, Braun warned.
“In the EU, they assume chemicals are guilty until proven innocent. In this country, we assume they’re innocent until proven guilty,” he said.
Manufacturers have been pressured by regulators and consumers to phase some types of phthalates out of certain products. But in some cases, those phthalates have been replaced by other questionable chemicals that might have potentially harmful health effects, too.
The bottom line
Children who were born to mothers with high levels of certain kinds of phthalates in their urine were up to 30 percent more likely to experience language delay, compared to those born to mothers with lower levels of the chemical.
The study adds to a growing body of research, which is still inconclusive, on phthalate exposure in utero.