The Alpha wave rythms say it all
In 1969, Dr. Sulman, head of the department of Applied Pharmacology at Hebrew University in Jerusalem at the time, brought in groups of people to spend some time in a room low in negative ions, and also in a room that contained an "overdose" of negative ions. While in each room, subjects were given word, figure, and symbol tests. They scored "significantly higher" on these tests when they were in the negative ion-enriched room. Plus, while in the negative ion room, they showed (via the electroencephalogram) a slower, stronger pulse rate of Alpha waves from the brain. Alpha wave rythms are a measure of the brain’s acitivity and health. A slow, strong Alpha wave pulse rate indicates healthiness, calmness, and heightened alertness. When the subjects were in the negative ion-deficient room, they showed signs of irratibility and fatigue in addition to lower test performance (Sulman, 1974).

The more difficult the better
In the study conducted by Surrey University at the Norwich Union Insurance Group headquarters, the employees in the computer and data preparation section that were exposed to high levels of negative ions showed a 28% increase in overall task performance. The more difficult the task, the more dramatic the improvement tended to be (Soyka, 1991).

Driving mad
In 1972 in Geneva, statistics showed that whenever there was a drastic change in the weather, and a consequent drop in the negative ion concentration in the air, traffic accident rates rose by more than 50% (Soyka, 1991).