This document outlines international standards for various elements in drinking water. It provides concentration limits and potential health effects for fluoride, lead, sulfates, chloride, iodide, nitrate, aluminum, barium, boron, and cadmium in water. Fluoride is beneficial between 1-2 ppm but harmful above 10 ppm. Lead should not exceed 50 ppb. Sulfates and chloride are acceptable up to 500 ppm and 250 mg/L respectively. Nitrates above 10 mg/L can cause methemoglobinemia in infants. The limits and health effects of other elements are also specified.

1. Water Quality
Criteria

2. International standards for drinking water are given below.
1-Fluoride
• Water is tested for Fluoride
ion concentration.
• Its deficiency is harmful and
causes diseases.
• Fluoride ion is added to water
to bring its concentration
upto 1ppm.

3. • Makes enamel on the surface of teeth.
• However, above 2ppm concentration
causes brown molting of teeth
• Above 10ppm causes harmful effects
to bones and teeth

4. 2-Lead
• Water gets contaminated with
lead.
• Upper limited of lead in water is
50ppm.
• Excessive amount can damage
liver and reproductive system.

5. 3-Sulphates
• Range of sulphates in drinking
water is 500ppm.
• Above this range it has harmful
effects.
• Moderate concentration is
harmless

6. 4-Cholride
• The limit of chloride ion is 250
mg/L.
• Above this limit it
corrosiveness of water.
• In combination with Sodium,
gives a salty taste to water.

7. 5-Iodide
• The limit of iodide is 4.0 mg/L.
• It is essential and beneficial
element in metabolism.
• Its deficiency can cause goiter.

8. 6-Nitrate
• The limit of Nitrate is 10mg/L.
• Above this, it can cause fatal
blood disorder in infants.

9. 7-Aluminium
• Its limit is 50-200ug/L.
• It has no necessary role in
human or animal diet.
• Non-toxic in natural water.
• Toxic in when pH of water gets
lower.

10. 8-Barium
• Its normal range in 2000ug/L.
• Concentration above 2000ug/L can cause
death.
• Smaller concentration can cause damage
to heart, blood vessels and nerves.

11. 9-Boron
• Its limit is 2.4mg/L.
• Its essential for plant
growth.
• May be toxic when
concentration is higher

12. 10-Cadmium
• Its range is 5ug/L
• Toxic when its range is
more than 5ug/L
• Can cause damage to the
liver, kidney.