Why is DDE persistent?
It’s stable, fat-soluble, and degrades extremely slowly.
What pesticide breaks down into DDE?
DDT
- How does DDE build up in birds?
It accumulates in fatty tissues and magnifies up the food chain.
How does DDE disrupt eggshell formation?
By interfering with enzymes and hormones in the shell gland.
What role does prostaglandin play?
It regulates calcium transport needed for shell deposition
Why were raptors hit the hardest?
They’re top predators → highest biomagnification.
How does DDE act as an endocrine disruptor?
It alters hormone signalling, including oestrogen pathways.
What does DDE do to calcium ATPase?
It inhibits the enzyme, reducing calcium availability for shells.
Why did banning DDT help bird recovery?
Lower exposure → thicker shells → improved breeding success.
Why are long-lived birds more vulnerable?
They accumulate DDE for years, building very high body burdens.
