1. General concepts

Clinical Evaluation Report Air Ionization

1. General concepts

Air ions are electrically charged molecules or atoms in the atmospherewhich are generated by cosmic radiation, waterfalls, friction forces in storms and byultravioletlightning.Generally speaking, an ion is formed when a molecule or an atom receives sufficiently high energy to eject an electron. Ions which lose an electron are negative and they are called also anions, while ions which gain an electron are positive and known also as cations [1-2] .

The atmosphere which surrounds the

Earth is subjected to a natural electric field characterized by an intensity that changes constantly due to local and global influences. Local influences are geographical location and weather conditions, while global influences mean daily electric field variations. The corona discharge, a basic principle of ionization, occurs in the presence of high intensity electric fields generated by natural phenomena such as thunderstorms or lightning.

High concentrations of negative ions are found near waterfalls or at seashores. They are generated by Lenard’s effect, which is also called spray electrification [1,3] . In particular, negative ions are generated from the surrounding air molecules by charging themselves when water drops collide with each other.

Artificial corona discharge is an efficient way to generate negative ions by applying a high negative voltage to a conductor. The intensity of the corona discharge depends on the size and shape of the conductor [1] . The main difference between corona discharge and Lenard’s effect is that the former charges negatively every substance in the air and generates ozone, the latter produces only superoxide ions [4] .

The first reported information of air ions dates back to the 19 th

century. According to many studies, high concentrationsof negative airions have a positive influence on human health, stress and cognition

[4-16] .