Prenatal exposure to the plastic chemical phthalate DiNP was found to cause shorter anogenital distance (AGD) (the distance between the anus and genitals) in Swedish boys.
The findings are concerning because past studies have linked DiNP to a shorter AGD in animals as well as other birth defects and changes in reproductive function in adult male humans, the Swedish Research Council reported.
Phthalates are used as plasticizers in soft polyvinyl chloride (PVC) and can be found in common household items. It has also been used as a replacement for diethyl hexyl phthalate (DEHP) as a plasticizer in soft PVC; in the past it has been suggested DiNp has anti-androgenic properties similar to DEHP.
To make their findings the researchers looked at the relationship between first trimester urinary metabolite concentrations of DEP, DBP, DEHP, BBzP as well as DiNP (which has never been included in past studies) and 196 Swedish boys at the age of 21 months. The babies' AG was measured by two pediatric nurses at the County Council of Värmland, Sweden.
The researchers found most of the phthalate metabolites were associated with a shorter AGD, even though the findings were not statistically significant in some cases.The strongest association was found to be between AGD and DiNP metabolites.
"These findings call into question the safety of the recent substitution of DiNP for DEHP in soft PVC, particularly since a shorter male AGD has been shown to be related to male genital birth defects in children (such as hypospadias and undescended testis) and impaired reproductive function in adult males (such as decreased fertility, impaired semen quality and lower serum testosterone levels) and the fact that human levels of DiNP are rapidly increasing globally," said Carl-Gustaf Bornehag, professor in Public Health Sciences at Karlstad University.
