Long-term biological effects of air ions and D.C. electric fields on Namru mice: First year report

This report describes for the first time the effects of long-term continuous exposures of animals to small air ions and D.C. electric fields. In this study we exposed 200 female NAMRU mice (25/cage) to the following conditions: ± high ions (2×10⁵/cm³), ± low ions (2×10³/cm³), ± field only and ground (ion depleted, no field). Specially designed cages provided a defined D.C. field of about 2 kV/meter in ionized environments, with somewhat lower values in the field only cages. Detailed mapping of ion flux originating from a tritium foil generating system (multiple sources in an overhead plate) indicated a well defined, but heterogenous pattern with eight peak areas. Using a 100 cm² probe, ion flux values ranged from 10^–12–10^–14 A/cm², with an average flux of 8.7±6.8×10^–13 A/cm² in high negative ion cages, with good reproducibility between cages.Measurements of serum glucose, cholesterol, and urea nitrogen (samples taken every three months) showed a number of small but consistent and statistically significant differences between animals maintained in different environments during the first year of exposure. Serum globulin and whole blood serotonin, however, did not show any significant environmental effects. Interestingly, pairwise comparisons between high negative and low negative ion conditions, or between high positive and low positive ion conditions, or between the two ground conditions, revealed no significant differences between cages. This argues for a similarity of environmental responses for the mice maintained in each of the compared conditions.The results of a multiple classification analysis for the entire first year showed a preponderence of effects for the ionized cages, although other conditions also had highly significant differences as compared to the grand mean value. While this study has shown effects of only small magnitude (compared to normal physiological variations) in the female NAMRU mice studied here, the significance of these results strongly validates the precept of long-term air ion effects in animals. Given the known variability of different species and strains, future studies will have to determine the actual range of responsiveness of animals exposed on a long-term basis to defined air ion and electromagnetic environments.Deceased December 8, 1982.