Question

Knock knee syndrome occurs due to the pollution of

• A. nitrates
• B. phosphates
• C. fluorides
• D. heavy metals

Answer 1

Answer: (C)

fluorides

Answer 2

Knock knee syndrome occurs due to the pollution of fluorides. The disease is characterised by stiffness and hardness of joints and bones. More than $13$ states of India have high concentration of fluoride (more than $1.5 \,ppm$) in ground drinking water.