Question

The concentration of fluoride, lead, nitrate and iron in a water sample from an underground lake was found to be 1000 ppb, 40 ppb, 100 ppm and 0.2 ppm, respectively. This water is unsuitable for drinking due to the high concentration of ______.  

Options

• fluoride

• lead

• nitrate

• iron

Answer 1

The concentration of fluoride, lead, nitrate and iron in a water sample from an underground lake was found to be 1000 ppb, 40 ppb, 100 ppm and 0.2 ppm, respectively. This water is unsuitable for drinking due to the high concentration of nitrate. 

Explanation:

The recommended level of fluoride in drinking water is 1 ppm or 1000 ppb. Lead, nitrate, and iron have upper limits of 50 ppb, 50 ppm, and 0.2 ppm in drinking water, respectively. Because of the high nitrate concentration, the water sample from the subsurface lake is therefore unfit for consumption.