2017 · Q113
Which one of the following is a major effect of long term consumption of drinking water containing little (less than 0.5 ppm) or no fluoride?
general-sciencebiotech-environment-science
- ACavity of tooth
- BErosion of nail
- CDeformation of bone
- DMottling of tooth
Explanation
Fluoride below about 0.5 ppm fails to protect tooth enamel, leading to dental caries (cavities). Excess fluoride causes mottling and deformation of teeth, and nail erosion is unrelated to fluoride deficiency. Hence (A).