Himalayan salt lamps are well known for their air purifying properties. How in the world can a lamp purify the air? Salt lamps attract moisture from the air to the lamp surface, where, due to the warmth, the water evaporates quickly. The evaporation produces negative ions into the air. Pollen, dust, dirt, pollutants, and allergens are suspended in the air due to their positively charged ions. The negative ions from the salt lamp neutralize the unhealthy positive ions so they can no longer be airborne floating around your home.