IB ESS SL 2.2.18 Non-biodegradable Pollutants Question Bank
Explain persistence, bioaccumulation and biomagnification of non-biodegradable pollutants.
- Syllabus
- First assessment 2026
- Course
- ESS SL
- Level
- SL
Explain persistence, bioaccumulation and biomagnification of non-biodegradable pollutants.

Figure A sample food chain from a marine ecosystem to show the concentration of persistent organic pollutants (POPs) and the energy within each trophic level
State the relationship between POPs concentration and trophic level.
State the relationship between POPs concentration and the trophic level.
POP concentration increases/is higher moving up to higher/at increasing trophic levels / positive/direct correlation / as one increases the other increases;
Note: Do not credit biomagnification or bioconcentration in response to this question.
Explain the relationship between POPs concentration and trophic level.
a. POPs bioaccumulate/bioconcentrate within organisms/tissues, as they are taken up from surrounding environment/polluted ocean water/food;
b. ... because POPs are non-biodegradable/don't break down...;
c. ...and result in biomagnification, as they pass from one trophic level to the next (across levels)...;
d. ...due to the decrease of biomass/energy (respiratory losses) up the food chain;
Note: Do not award marks if similar statements are given in 2(b) and 2(c)