Mice were exposed to an atmosphere enriched with positive or negative small ions (density: 52000 each of positive or negative charge carriers/cm3 air); after the exposure times of 5, 30 min and 1, 3, 10 d, we determined the norepinephrine content of the brain.
Results: In the case of negative ionization of the air, no difference to untreated controls could be determined at any of the above exposure times. Positive ions, however, cause an elevated norepinephrine level after an exposure time of up to one day; after the exposure times of 3 to 10 d, a drop in the norepinephrine level could be observed in comparison to the control data.
Conclusion: Negative ions have a neutral effect under the given bioclimatologic conditions. However, positive charge carriers cause stress after shorttime application in excess. After longer exposure, a state of exhaustion can be observed in the form of a lowered norepinephrine level.