More bad phthalate news: Early life exposure linked to decreased motor skills

Kids exposed to phthalates prenatally and as 3-year-olds have decreased motor skills later in their childhood, according to a new study.

The study is concerning because phthalates are so widely used. Previous research found that phthalate exposure is linked to decreased motor skills for infants and toddlers but this is the first study to suggest these problems may persist as the children age.

"As lower scores on measures of motor development have been associated with more problems in cognitive, socioemotional functioning and behavior, the findings of this study have implications related to overall child development," the researchers wrote in the study published online in Environmental Research.

"This is a crucial public health challenge given the globally ubiquitous nature of phthalates," they added.

Phthalates—used widely in vinyl flooring, cosmetics, detergents, lubricants and food packages—are endocrine disrupting chemicals, meaning they alter the proper functioning of people's hormones. They've also recently been found in diapers and women's sanitary pads.

The chemicals have been linked to multiple health problems, including birth and reproduction problems, diseases, impaired brain development, diabetes and cancer. Just last week researcher linked phthalates to reduced lung function as well.

Researchers looked at the prenatal phthalate exposure of 209 children, as well as exposure when they were 3 years old. They found girls that were exposed to higher levels of phthalates while in the womb had decreased motor skills at age 11; and boys exposed to higher levels of phthalates at age 3 had decreased motor skills at age 11.

The women and children are from an ongoing study cohort in New York City; the mothers are all either Black or Dominican.

Senior author of the paper Pam Factor-Litvak, a professor and epidemiologist at the Columbia University Medical Center, told EHN the motor skills tests included "fine motor skill" tests such as whether or not kids can put a peg in a peg board or coordinating with their upper limbs, and a focus on larger muscle groups, with tests such as walking on a balance beam or running.

She said the importance of motor skills is often overlooked in research. "Motor function is so important and it has a lot to do with cognitive and social development as well," she said.

The researchers didn't look at how the phthalates might be impacting motor skills; however, previous studies have shown the chemicals to alter proper function of the thyroid, which is crucial to proper motor skills and brain development. The chemicals could also disrupt vital neuron activity in the kids' brains, which are involved in motor skills' development.

Factor-Litvak said it's not entirely understood why they saw different impacts on boys and girls but that phthalates are known to disrupt sex steroid hormones such as estradiol and androgens, which could impact boys' and girls' brains in different ways.

The study alone doesn't prove the compounds are causing these impacts, however, it adds to mounting evidence. Multiple previous studies have found a link between phthalate exposure and decreased motor skills.

Those studies focused on newborns to children around preschool age. This study suggests that these prenatal and early life exposures may continue to impact children well into their childhood years—and maybe beyond, Factor-Litvak said.

"That's what we worry about – the downstream impacts after childhood. [Those impacts] haven't been studied," she said.