Years of research have shown that a wide range of chemical substances may have endocrine disrupting effects. Authorities and NGOs around the world have compiled lists containing thousands of existing substances that are suspected of having endocrine disrupting effects. However, the scientific evidence related to these chemicals’ endocrine disrupting properties varies greatly from very strong to very weak.
There is political consensus both in Denmark and internationally that there is a need to minimize exposure to endocrine disrupting substances. However, in order to prioritize efforts and increase chemical safety, it is important to know exactly which substances have an endocrine disrupting effect on humans and the environment.
Researchers from the National Food Institute, Technical University of Denmark, and the University of Southern Denmark have therefore compiled a list of suspected endocrine disrupting substances in a project for the Danish Environmental Protection Agency. The researchers have then assessed the scientific literature for a number of these substances, based on the criteria that the EU—after many years of delay—has set for biocides and pesticides.
The Danish Environmental Protection Agency has supported the project because the scientific documentation can be used to influence EU regulation, so that it can better protect consumers and the environment.
Review of the scientific evidence
In the project, the National Food Institute reviewed the many existing lists, which in total contain more than 7,000 suspected substances. Based on these lists, a priority list was compiled containing substances where data indicate that they have an endocrine disrupting effect and where there is a strong likelihood that humans and the environment will be exposed to them.
From the priority list of 172 substances, the researchers have studied the literature for 52 selected substances and then selected 13 substances, which they have carefully evaluated based on the EU’s new criteria for biocides and pesticides.
For each of these substances, the researchers have assessed the quality of the studies that were used to identify the substances as potentially endocrine disrupting. In the evaluation, they also considered how strong the causal link is between an endocrine disrupting mode of action of a substance and the harmful effect.
This work resulted in a list containing nine substances, which the researchers consider can be termed endocrine disruptors based on the new criteria. The substances include e.g. the pesticide prochloraz, which can be used throughout the EU except for Denmark and Malta, as well as BPAF (Bisphenol AF), which is an alternative to BPA (Bisphenol A).
While there is solid scientific evidence to show the endocrine disrupting effects for nine of the 13 substances, researchers point out that there are gaps in the available knowledge related to the other four. However, the researchers conclude that the data clearly show that the four are suspected endocrine disrupting chemicals.
Tip of the iceberg
According to the researchers, the list of nine endocrine disruptors shows only the tip of the iceberg. For some of the other suspected endocrine disrupting substances a detailed assessment is required.
For many other substances, more research and more data are needed to assess the substances’ endocrine disrupting effects, possible harmful effects, and to assess the extent to which people and the environment are exposed to the substances.