Even though they are call Negative Ions they help in a positive way. The terms Negative and Positive are actually reversed. In this context, and although a misnomer supposedly blamed on Benjamin Franklin, it is said that we are stuck with this 18th century terminology, since electrons and atoms were not quite as well understood then as they are today.
Negative ions freshen and purify the air. Negative ionization does a superb job of eliminating most tiny particles that float in the air. (Even when the air in a room seems calm, tiny particles are usually suspended in the air because of the convective air currents.) An ionized room can help people with allergies because allergens such as animal dander, mold spores and pollen will clump together and fall to the floor to be vacuumed up rather than left floating in the air to be breathed in where they can cause allergic reactions.
Ionized room air does not have to pass through a filter or be circulated by a fan to be cleaned. In a filter-type purifier with a fan or blower, only the air that goes through the filter can be cleaned. And even then, the tiniest particles still can flow through the filter. These tiny particles can be better removed by ionization than filtering, even HEPA filters.
Remember, the word negative is good, in this context. You will find high levels of negative ions in more natural settings: at the beach, in the mountains, in the country, in pine forests, near waterfalls — all the places that we feel good after we visit them.
Compare the negative ion count, per cubic centimeter (about the size of a sugar cube), in the following examples:
- Urban environments, for instance, Los Angeles freeway during rush hour has about 100 negative ions per cubic centimeter
- Fresh country air contains about 2,000 to 4,000 negative ions per cubic centimeter
- Yosemite Falls, over 100,000 negative ions per cubic centimeter!
Perhaps now we can understand that wonderful, uplifted feeling we experience when we are near a waterfall or enjoying the outdoors high in the mountains around those beautiful pines. These are two places that thousands of negative ions occur. As you can see, they create a ‘positive’ effect on human biochemistry. » Read more: What Are Negative Ions?