Summary
Chemicals such as BPA mimic or block hormones, disturbing development and reproduction.
In depth
Examples: BPA, phthalates, DDT metabolites, some pesticides. Effects: altered puberty timing, reduced fertility, feminisation of fish below sewage outfalls. Low-dose and timing effects are debated.
Chemicals may mimic hormones or block receptors. Effects are strongest in development. Regulation restricts some chemicals.
Key idea: tiny amounts can have effects because hormones act at very low doses.
Endocrine disrupting chemicals (EDCs) interfere with hormone synthesis, transport, binding or breakdown. They may mimic natural hormones (bisphenol A and some phthalates mimic oestrogen), block receptors (some pesticides such as vinclozolin block androgen receptors) or alter thyroid function (PCBs, perchlorate).
Effects are greatest during sensitive developmental windows, and may include altered sexual development, reduced fertility, earlier puberty and effects on metabolism and thyroid. Wildlife examples: feminised male fish downstream of sewage works and imposex in snails exposed to tributyltin. Dose-response may be non-monotonic. Regulation is evolving as evidence builds.
Example: diethylstilbestrol (DES) given to pregnant women caused cancers in daughters.
Frequently asked questions
What is Endocrine Disruptors?
Chemicals such as BPA mimic or block hormones, disturbing development and reproduction.
Which area of biology covers Endocrine Disruptors, and how advanced is it?
Endocrine Disruptors is one of the 54 topics in Reproduction & Endocrinology. It is rated Advanced, so it suits learners who want specialist depth. Related topics in this area include Circadian Endocrinology, Hormones, Steroid and Peptide Hormone Mechanisms.
Why does Endocrine Disruptors matter?
Exposure is widespread.
Can you give an example of Endocrine Disruptors?
Pill-derived ethinyloestradiol in water affects fish.
What should I learn before Endocrine Disruptors?
Work through the Beginner topics in Reproduction & Endocrinology first, such as Reproduction, Asexual Reproduction, Sexual Reproduction, then return to Endocrine Disruptors. Advanced topics assume the Intermediate vocabulary.
What topics are related to Endocrine Disruptors?
The closest topics to Endocrine Disruptors are Circadian Endocrinology, Hormones, Steroid and Peptide Hormone Mechanisms, Pregnancy. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Endocrine Disruptors?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Endocrine Disruptors. To practise the whole of Reproduction & Endocrinology, use the Reproduction & Endocrinology quiz.
How is Endocrine Disruptors different from Circadian Endocrinology?
Endocrine Disruptors: Chemicals such as BPA mimic or block hormones, disturbing development and reproduction. Circadian Endocrinology: Hormone levels follow daily cycles, with cortisol peaking in the morning and melatonin at night. Read both side by side and note what each one explains.
How should I study Endocrine Disruptors step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Circadian Endocrinology and explain the difference aloud. Finally, take the Reproduction & Endocrinology quiz and come back to this page for any question you miss.