What are endocrine disruptors?

Endocrine disruptors are chemical substances of natural or artificial origin whose action alters the functioning of the hormonal (endocrine) system. They can have an impact on the environment and the health of living organisms.
There is a wide variety of endocrine disruptors and the sources of contamination to which humans and animals are exposed are numerous:

• natural or synthetic hormones: oestrogen, testosterone, progesterone present in contraceptives or sterility treatments;
• more than a thousand products of various chemical types, used in plastics, cosmetics, plant protection products or solvents, etc;
• natural compounds such as phyto-estrogens present in a wide variety of plants (genistein, mycotoxin, etc.).

These emerging pollutants are particularly worrying and our knowledge is still limited.

Issues related to endocrine disruptors

Health and environmental issues

Much research is being conducted to determine the extent of their effects.
To date, the scientific communities have demonstrated that endocrine disruptors have major health and environmental impacts on :

• wildlife,
• ecosystems,
• human beings.

Studies have shown that these endocrine disruptors are responsible for many disturbances:

• contributing to the erosion of biodiversity ;
• impacting on the reproductive systems of wildlife, including humans
• causing fertility problems, malformations of the reproductive system
• promoting the appearance of cancers such as breast cancer, prostate cancer, thyroid cancer, etc.

To sum up, endocrine disruptors are emerging pollutants that contribute to the disruption of certain hormone-related functions in the body:

• alteration of reproductive functions, 
• malformation of reproductive organs, 
• appearance of tumours, 
• disruption of the thyroid system, the nervous system and cognitive development.

A complex assessment of their toxicity

Assessing the mechanisms of action of endocrine disruptors is very complex.

The dose/effect relationship is not always validated.

Traditionally, in toxicology, the harmful effects of toxic substances are proportional to their concentration. Thus, the higher the dose of exposure, the greater the effects. In the case of chemical toxins such as endocrine disruptors, even a low dose can induce effects: this will depend on the length of exposure, chronic or otherwise, to this type of substance: even a tiny dose ingested every day could have significant impacts in the medium or long term.

Bioaccumulative substances

In addition, some endocrine disrupting substances can bioaccumulate to significant levels in the body, particularly in fat, which makes the assessment of its toxicity over time complex.

Cocktail effects

There is a multiplicity of endocrine disruptors and the biological effects of these substances can interact with each other. A single substance can have multiple or even interdependent effects, depending on the substances present with it.

Given this complexity, endocrine disruptors cannot be analysed solely by concentration thresholds. It therefore seems more appropriate to focus these analyses on effects, rather than concentrations.

Contribution of Tame-Water

For more than 20 years, Tame-Water has been carrying out biomonitoring of water. Endocrine disruptors are substances on which Tame-Water has developed specific products and laboratory analyses.

These solutions, based on bioassay technologies, enable it to analyse the acute or chronic toxicity induced by these substances, taking into account the potential cocktail effect. This approach appears to be the most suitable method for assessing "endocrine disruptor" pollution and its potential toxicity on the target environment.