Endocrine Disruptors

Question 1

What are endocrine disrupters?

Answer 1

Chemicals that mimic or block hormones when absorbed in body, & disrupt body’s normal functions

Question 2

Give some examples of endocrine disrupters

Answer 2

• Herbicides
• Fungicides
• Insecticides
• Nematocides

Question 3

Describe the action of endocrine disrupters

Answer 3

• Bind to hormone receptors & activate cell (hormone mimics)
• Changing production of a hormone
• Bind to hormone receptors & block natural hormone action (antagonists)
• Changing breakdown/ metabolism of hormones

Question 4

What are some effects of endocrine disrupters?

Answer 4

• Abnormal sexual development
• E.g. Decreased T levels, small penises & malformed ovaries in alligators, sex reversal in fish

Question 5

Give an example of a species affected by endocrine disruptors.

Answer 5

• Exposure of pregnant sheep to a mixture of
  environmental chemicals added to pasture in
  sewage sludge caused:
  • Reduced body weight (12–15%) in male &
  female foetuses
  • Significantly reduced testis weight (-32%),
  number of Sertoli cells (-34%), and Leydig
  cells (-37%)
  • Low foetal testosterone and inhibin A