Call for more research into phthalate health risks

Phthalates are found in a wide variety of products including cosmetics, medical devices and building materials, raising concern that widespread exposure poses health risks.

A committee of the independent National Research Council concluded that the US Environmental Protection Agency should carry out more research into cumulative risks.

The panel also recommended that chemicals with similar health effects to phthalates should be considered rather than looking only at chemicals that are similar in structure.

The multiple exposure question​

In deciding that more research was necessary, the Research Council sought to establish whether humans are exposed to multiple phthalates at any given time and whether enough evidence exists linking multiple exposure sources to health problems.

The panel said existing studies show that humans, including unborn babies, experience widespread exposure to various phthalates.

Looking at the evidence on health risks, the report said animal studies have increased understanding of the potential health risks from phthalates, although few human studies are available.

What evidence there is, points to a range of effects on the male reproductive system from exposure to various phthalates although the panel said the severity of the effects differed from phthalate to phthalate with some exhibiting no adverse health risks at all.

Differences were also observed depending on the age of the animals at the time of exposure with foetus being most sensitive to risk.

Cumulative risk assessment needed​

Overall, the Research Council concluded that the current body of research justifies a cumulative risk assessment on phthalates. The report also said the EPA should include antiandrogens in their research because these are also linked to male reproductive development.

Behind this last recommendation is a call for a change of conceptual approach. The panel said chemicals that cause similar health effects should be studied together in order to properly understand how exposure to different chemicals may result in the same health outcomes rather than grouping chemicals together by chemical structure and ignoring the nature of human exposure.

The National Research Council has also been in the headlines recently for criticisms made of the US government strategy on nanotechnology.

In a report published earlier this month, the Research Council said the development of a better plan for research into the health and public risks posed by nanomaterials was imperative in view of increased public exposure from consumer products.