Here’s a situation that happens disturbingly often. First, researchers reveal that a certain chemical commonly found in products is toxic, and it’s either banned or companies are pressured into removing it. Luckily, the chemical industry pops up with a new replacement that they claim is safer–but in fact, just hasn’t been tested as extensively for safety. In the end, it’s revealed that the replacement chemical is just as bad as the chemical it’s replacing.
That’s what is happening with DiNP, a phthalate (a class of chemicals found in consumer products) commonly used in auto parts, vinyl flooring, as a plastic softener for PVC products, and as an adhesive. DiNP is used in the U.S. and Europe as a replacement for DEHP, a different phthalate that is known to have toxic effects.
One of DEHP’s known effects, based on past studies, is causing shorter anogenital distance (AGD)–the distance between the genitals and the anus–in baby boys. Men with shorter AGD than other men of the same age tend to have reproductive problems; a shorter AGD is also linked to genital birth defects and a lower testosterone level.
In a study published today in the journal Environmental Health Perspectives, researchers offer up evidence that prenatal DiNP exposure in baby boys is also linked to a short AGD–an indication that DiNP may have the same nasty side effects as DEHP, the chemical that it’s replacing. “The reason why we hadn’t seen a link between AGD and DiNP before is because no one looked at it,” says Carl-Gustaf Bornehag, a professor of public health sciences at Karlstad University in Sweden and the first author of the study.
The most troubling part of these findings is that DiNP use is increasing as DEHP is phased out.
This research is part of a much larger study, called the Swedish Environmental Longitudinal, Mother and Child, Asthma and Allergy (SELMA) study, that is following over 2,000 mothers and children from early pregnancy in an effort to investigate the effects of exposure in early life to endocrine disrupting chemicals like phthalates. Bornehag suspects that the AGD study may be just one piece of a puzzle pointing at the different ways that endocrine disruptors affect men and women.
“We know that asthma and respiratory problems are more than doubly found in boys compared to girls. If you go to neurodevelopment disorders, autism spectrum disorder is four times more common in boys than girls. There may be a pattern here,” says Bornehag. “One hypothesis is that if there is exposure to an estrogen-like compound or androgen-like compound, we can expect that effects will be different in boys and girls.”
There are four tracks that the researchers are following in the SELMA study: reproduction, neurodevelopment, asthma and allergy, and metabolic effects. They are looking at endocrine disruptors’ effect on everything from time of puberty onset to language abilities in young children. “The sexual dimorphism is a cloud over this,” says Bornehag.