Babies recently treated with infant personal care products such as lotion, shampoo, and powder, were more likely to have man-made chemicals called phthalates in their urine than other babies, according to a UW and Seattle Children’s Hospital Research Institute study appearing in the February issue of the journal Pediatrics.
Phthalates (pronounced thowlates) are added to many personal care and cosmetic products, as well many common household plastic and vinyl products, and some studies suggest they may affect reproductive development in humans.
Animal-based studies of phthalates have found that the synthetic chemicals can harm reproductive system development, and studies in humans have found that prenatal exposure or exposure through breast milk can alter hormone concentrations. Early childhood exposure has not been extensively studied, so additional research is needed to determine if phthalate exposure can indeed cause reproductive development problems or other adverse effects in infants.
In this study, the researchers set out to see if use of personal care products was associated with urine phthalate concentrations. To accomplish this, they collected urine samples from 163 infants aged 2 months to 28 months, and measured the levels of nine different phthalates in those urine samples. They also had the babies’ mothers fill out questionnaires on their use of infant personal care products in the past 24 hours.
When they cross-referenced the data, they found that the use of baby powder, lotion, and shampoo were each strongly associated with higher phthalate levels in the urine.
The use of baby wipes and diaper cream were not strongly associated with increased levels of phthalates.
The scientists also found that every baby had detectable levels of at least one phthalate in their urine, and about 81 percent of the infants had detectable levels of seven or more phthalates. Babies who were 8 months old or younger had stronger associations between product use and phthalate concentrations, as did babies whose mothers used more infant personal care products.
Phthalate exposure in early childhood has been associated with altered hormone concentrations as well as increased allergies, runny nose, and eczema. Babies may be more at risk than children or adults, the researchers said, because their reproductive, endocrine, and immune systems are still developing.
The study was led by Dr. Sheela Sathyanarayana, an acting assistant professor of pediatrics at the UW and a researcher with Seattle Children’s Hospital Research Institute.