It's only a pollutant until you leave it out in the sun for a few days, after which all of the water has evaporated back into the atmosphere and you're left with mostly sodium chloride, but also a few other healthy micronutrients like potassium, magnesium, and calcium.
This process costs $0, requires zero energy (besides that provided by the sun) and has worked reliably for many thousands of years.
It's only a pollutant until you leave it out in the sun for a few days, after which all of the water has evaporated back into the atmosphere and you're left with mostly sodium chloride, but also a few other healthy micronutrients like potassium, magnesium, and calcium.
This process costs $0, requires zero energy (besides that provided by the sun) and has worked reliably for many thousands of years.