Prenatal DiNP Phthalate Exposure and Changes in Baby Boys’ Genitals

Study raises concern about DiNP, a phthalate being used in increased amounts in products that contain vinyl plastics, and the impact on the developing fetus

newborn
This study raises concern about DiNP, a phthalate being used in increased amounts in products that contain vinyl plastics, and the impact on the developing fetus.

Boys exposed in the womb to high levels of a chemical found in vinyl products are born with slightly altered genital development, according to research published today. The study of nearly 200 Swedish babies is the first to link the chemical di-isononyl phthalate (DiNP) to changes in the development of the human male reproductive tract.

Abstract:

Background:
Phthalates are used as plasticizers in soft polyvinyl chloride (PVC) and in a large number of consumer products. Due to reported health risks, di-isononyl phthalate (DiNP) has been introduced as a replacement for diethyl hexyl phthalate (DEHP) in soft PVC. This raises concerns since animal data suggest that DiNP may have anti-androgenic properties similar to DEHP. The anogenital distance (AGD) – the distance from the anus to the genitals – has been used to assess reproductive toxicity.

Objective:
The objective of this study was to examine the associations between prenatal phthalate exposure and AGD in Swedish infants.

Methods:
AGD was measured in 196 boys at age 21 months and first trimester urine was analyzed for ten phthalate metabolites of DEP, DBP, DEHP, BBzP as well as DiNP and creatinine. Data on covariates were collected by questionnaires.

Results:
The most significant associations were found between the shorter of two AGD measures (anoscrotal distance, AGDas) and DiNP metabolites and strongest for oh-MMeOP and oxo-MMeOP. However, the AGDas reduction was small (4%) in relation to more than an interquartile increase in DiNP exposure.

Conclusions:
These findings call into question the safety of substituting DiNP for DEHP in soft PVC, particularly since a shorter male AGD has been shown to relate to male genital birth defects in children and impaired reproductive function in adult males and the fact that human levels of DiNP are increasing globally.

Sources and more information:
  • Prenatal Phthalate Exposures and Anogenital Distance in Swedish Boys, EHP, DOI:10.1289/ehp.1408163, 29 October 2014.
    Full study PDF.
  • Plastics chemical linked to changes in baby boys’ genitals,
    EHN, Oct. 29, 2014.

PVC Flooring related to Human Uptake of Phthalates in Infants

#Phthalates – used as softeners in PVC flooring material and suspected as #EDCs – are absorbed by the body of the infants and the amount absorbed depends up on the body area of the infants.

Image of an infant on pvc flooring
Phthalates are absorbed by the body of  infants. The amount absorbed depends up on the infants body area

Phthalates are chemical compounds present in commonly used materials like cleaning solvents, toys, etc. They are also used as softeners in poly vinyl chloride (PVC) flooring material. Earlier studies have found that phthalates can result in several chronic diseases in children like asthma and allergies. They are suspected to be endocrine disrupting chemicals (EDCs). A 2012 study conducted by scientists from Karlstad University in Sweden and published in the journal Indoor Air has found that phthalates can be absorbed by the bodies of infants and produce asthma in them.

For their research, the scientists led by Carl-Gustaf Bornehag, professor of public health at Karlstad University, randomly selected 83 children from Varmland, Western Sweden. All the children were between the ages of two and six months. Urine samples, collected from the children, were analyzed for the presence of metabolites of di-ethyl phthalate (DEP), di-butyl phthalate (DBP), butyl benzyl phthalate (BBzP) and di-ethylhexyl phthalate (DEHP). The family members of the children were also asked to fill up a questionnaire elated to their lifestyles and to their indoor environmental factors including the flooring material used in their homes.

The researchers found that the levels of metabolites of BBzP were significantly higher in those infants whose bedroom had PVC flooring. It was also seen that the levels of this metabolite in the urine corresponded to the surface area of the infants. It was noted that the levels of the metabolites of DHEP were higher in two months old infants who were not solely on breast milk compared to those who were completely breast fed.

The study clearly shows that phthalates are absorbed by the body of the infants and the amount absorbed depends up on the body area of the infants. These chemicals also reach the infant formula through indoor dust and can be absorbed through the food.

Sources and More Information: