Question

Match List-I (Type of impurity) with List-II (Harm caused) and select the correct answer using the codes given below the lists:

List-I

A. Excess of nitrates
B. Excess of fluorides
C. Lack of iodides
D. Excess of chlorides

List -II

1. Brackish water
2. Goiter
3. Fragile bones
4. Blue babies

• A. A-1, B-3, C-2, D-4
• B. A-1, B-2, C-3, D-4
• C. A-4, B-2, C-3, D-1
• D. A-4, B-3, C-2, D-1

Answer 1

The correct option is D A-4, B-3, C-2, D-1

(c) Concentrations of fluorine upto 1.0 mg/L in drinking water help to prevent dental cavities in children. During formation of permanent teeth, fluoride combines chemically with tooth animal resulting in harder, stronger teeth that are more resistant to decay. When concentration of fluorides exceed 2.2 mg/L, it results in discoloration of teeth called mottling. Excess fluorides also result in bone fluorosis and other skeleton abnormalities.