Question

The permissible limit of fluoride ion in drinking water is?
A.1.5ppm
B.10ppm
C.20ppm
D.25ppm

Answer 1

Hint: Permissible exposure limit (PEP) is established by occupational Safety and Health Administration (OSHA). It is a legal limit in the United States for high level exposure of chemical substances such as fluoride or pollutant etc. and physical agents like noise.

Complete step by step answer:
Water is the primer necessities of life.
Our groundwater can be contaminated by the several chemicals like nitrate, zinc, chloride sulphate and fluoride etc. Microbe can also contaminate the water.
Endemic fluorosis resulting from high fluoride concentration in groundwater is a public health problem in India.
Fluoride contamination in water varies 1.0 to 400 mg/L.
The fluoride level increases in water due to the presence of natural rocks because it is rich in fluoride source.
Fluoride levels in surface water are generally low, ranging from 0.01 to 1.5 mg/L, and it’s lower than ground water.
Some agency’s like APHA (American public health association), WHO (World health organization), ISI (Indian standard institutions) 1991 and CPCB (central pollution control board) setted up permissible limits of fluoride in drinking water.
According to World health organization (WHO) in 1984 - - -> 1.5 ppm (international standards for drinking water)
Indian council of medical research (ICMR) - - -> 1.0ppm.
According to this theoretical concept, the correct answer is A i.e 1.5ppm.



Note:
If fluoride concentration is above 1.5ppm in drinking water cause dental fluorosis and much higher concentration cause skeletal fluorosis. Low concentration of fluoride in water means less than 1.5 ppm (approximately 0.5) in drinking water provides protection against dental caries.