DEHP is teratogenic in mice

More and more studies in recent years have shown that the banned plastiziser: Di(2-ethylhexyl)phthalate (DEHP), is an endocrine disruptor, which disturbs the male reproduction. A new study documents, that DEHP also is teratogenic  in pregnant mice receiving  with oral gavage 500 mg DEHP/kg body weight dissolved in corn oil from embryonic days (E)7 to 16.  
DEHP

Structure formula for DEHP

Fetuses from mice eksposed to ≥250 mg DEHP/kg b.w. had a significantly reduced survival rate, and that doses of DEHP were teratogenic and induced exencephaly (brain tissue outside the skull) and limb malformations, such as polydactyly in the fetuses.

Even at exposures to 5 mg DEHP/kg b.w. adverse effects to the germ cells in the testes.

This study was conducted by researchers from the large and important government institute: NIEHS (National Institute of Environmental Health Sciences) located in Research Triangle Park, North Carolina, USA. The present director is fantastic Linda Birnbaum.

niehs_building

Picture of NIEHS buildings

NIEHS is the place where the pioneering, Danish genotoxicologist: Heinrich Malling (1931-2016), made his most important research during the years 1972-2004. Most of the time I was in contact with this legendary person, and I visited him twice. He was also visiting and guest lecturing in Denmark several times.  Curiously, in 1972-74 I was  his oldest daughter Tove’s high school teacher in Chemistry.

Heinrich Malling

Late picture of Heinrich Malling

In the city of Visby, Gotland, Sweden, the Nordic research organisation: NORDFORSK organised 41 years ago in May 1976 a Nordic symposium about organic toxicants in the water environment.

Nordforsk symposie 1976

At the symposium I presented an overview lecture about: ”Phthalates in the environment”. Among others I mentioned that animal studies had indicated that exposure to small doses of phthalates in pregnant mice  resulted in dead fetuses. At that time not so much more was known.

Based on the structural similiarities between phthalates and the well established teratogenic drug: Thalidomid, I postulated that phthalates probably also were teratogenic. The new study from 2017 has finally proven that. The two chemical structures:

PAE 1

Dialkyl phthalate


thalidomid
 Thalidomid

My postulate got much attendence in the Swedish press, and critical reactions were received from the plastic industry, which then and still is the main consumer of phthalates. They refused then and later that phthalates were hazardous. By time the debate died out.

At that time and as a follow-up of our research the Danish EPA suggested, that phthalates should be black-listed in the Baltic Sea Convention, the Paris Convention and in the EU Water Framework Directive. However, the opposition against that by other countries were too tough.

Unfortunately, Denmark was far too early out then! Nowadays, most countries agree that phthalates belongs to a hazardous group of substances.

This post is also available in: Danish

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