Question

Knock-Knee syndrome results due to pollution of:
A. Heavy metals
B. Fluorides
C. Nitrates
D. Phosphates

Answer 1

Hint: Knock-Knee syndrome is a syndrome in which there are angular deformities of the knee in which the deformity of knee points inwards. A person whose knees touch each other but ankles do not touch while standing is considered to have Knock-Knees.

Complete answer:
A child whose knees touch and ankles do not while standing is known to have knock knee syndrome. This condition is usually observed when the child is about 2-3 years old and may increase in severity when the child is 4 years old. It usually gets self-corrected when the child is about 7-8 years old but if the sign of correction of bones doesn’t appear from 6years of age then it is believed to be an underlying bone disease such as osteomalacia or rickets.
Osteomalacia is a bone disease which causes softening of bones caused by deficiency of vitamin D. Rickets is a disease which is also caused by vitamin D deficiency which is characterized by imperfect calcification and distortion of bones mostly in the region of legs.
Knock knee can also result due to excessive intake of raw metals via contaminated water having high contents of minerals such as silica and fluorides.

So, the correct option is option B.

Additional information: Fluoride is naturally present in soil, water and foods. It can be produced synthetically for use in drinking water, toothpaste, mouthwashes and many other chemical products. This is used to prevent demineralization of teeth. But a number of health issues arise when their concentration exceeds the normal value. Some of which are:
Dental fluorosis: The exposure of children to high concentration of fluoride when their teeth are developing can result in mild dental fluorosis. Some tiny white streaks or spots can be observed on the enamel of the tooth. It can also occur if children below 6 years use mouthwash containing fluorides.

Skeletal fluorosis: The excess exposure to fluorides can also cause severe bone diseases called skeletal fluorosis. In this disease the bones get hardened and less elastic due to which they become easily breakable and result in severe pain.

Note: The increased fluoride concentration can cause various diseases out of which two are dental fluorosis and skeletal fluorosis. The rest of conditions caused by fluorine are thyroid problems, neurological problems, cardiovascular problems, reproductive issues, acne and other skin problems etc.