Michael A Persinger and Linda S. St-Pierre
A total of 165 male and female rats that had been exposed during their entire prenatal development to either one of two complex, patterned magnetic fields or to reference (colony) conditions were monitored for emergence of “spontaneous” body tumours until old age (two years after birth). The two patterns were a frequency modulated (FM) field that has been shown to slow malignant cell but not normal cell growth in culture and a complex-sequenced (CSF) field. It was composed of 8 components with 6 of these components containing 8 subcomponents presented for 200 ms for 10 s every 40 s. Significantly greater proportion (33%) of the old rats that had been exposed prenatally to the complex-sequenced field displayed tumors (primarily mammary adenocarcinoma and fibrocarcinoma varieties). Most of these tumors occurred in rats that had been exposed to 30 to ~600 nT strengths but not less than 30 nT or greater than ~600 nT intensities. In comparison 4% of the rats exposed to the single, repeated frequency-modulated field exhibited tumors. The prevalence for normal background colony room conditions was 2%. These data suggest that exposure during prenatal development to weak intensity magnetic fields whose temporal patterns were designed to be convergent with the timing of base sequencing could increase the probability of the development of cancer during the later stages of life. However the frequency-modulated magnetic field pattern that suppress the growth of human breast cells in culture and elicits strong analgesia in rodents produced no significant increase in emergence of tumors in later life compared to non-treated rats.