Advocates say the lamps work in two ways:
Pull in particles. These lamps supposedly attract allergens, toxins, and pollutants to their surface.
Possibly release negative ions. Some people believe negative ions in the air have health benefits.
Ions are molecules that have undergone a change in charge. Negative ions have gained an electron. Positive ions have lost one.
Ions are all around us. Some come from particles from outer space that make their way to Earth. Others form closer to home, from radiation, sunlight, lightning, or the collision of water droplets in a waterfall.
Some people say they feel more refreshed and clear-headed after a storm, a feeling they believe is due to the amount of negative ions in the air. Commercial ionizers and purification systems also produce negatively charged ions to create cleaner and more comfortable indoor spaces.
Himalayan salt lamps supposedly produce negatively charged ions while water molecules from the air attract to -- and then evaporate from -- the warmth of its surface. Those who believe in the health benefits of these lamps give negative ions much of the credit.