6.4.4—UV radiation impacts
- Syllabus
- First assessment 2026
- Objective
- 6.4.4
- Level
- SL
Trace Two Effects of Reduced Ozone
Less stratospheric ozone increases surface UV, creating separate health/DNA and ecosystem/photosynthesis pathways.
UV can damage DNA, causing mutations and increasing cancer risk; in humans it contributes to sunburn, premature skin ageing and cataracts. It can also reduce phytoplankton photosynthesis and change food-web productivity.
A rise in surface UVB can affect exposed skin and eyes while separately reducing phytoplankton photosynthesis; each pathway needs its own receptor and evidence.
Name the receptor, UV exposure and mechanism—photosynthetic inhibition, DNA damage, skin injury or lens damage.
More UV does not produce one identical impact in every species or habitat.