Environmental levels of phthalates can harm male reproductive development in humans, a study has found

US researchers from the University of Rochester, writing in Environmental Health Perspectives, identified an association between pregnant women’s exposure to phthalates and adverse effects on genital development in their male children – the first time a link has been shown for humans. Most previous studies focusing on phthalate prenatal exposure were in rodents.

Higher levels of four phthalate chemicals in mothers correlated with a higher-than-expected number of abnormalities in genital development – particularly the “anogenital” distance, measured from the anus to the genitals. Data was collected from 85 mother-son pairs.

Dr David Cadogan, director of the European Council for Plasticisers and Intermediates, said the organisation was taking the report “very seriously” and was consulting its scientific advisors. “The worrying thing is we are talking about humans,” he said.

In his initial evaluation, he saw two potential flaws in the research: the real level of exposure to phthalates and the measurement of the anogenital distance. The latter, he said, “was not an easy measurement to make. The range of size is very small – there’s not much variation”.