Radiofrequency fields and teratogenesis

Abstract

Experimental studies that sought teratologic effects or developmental abnormalities from exposure to radiofrequency electromagnetic fields (RFEMF) in the range 3 kHz-300 GHz are critically reviewed for their possible consequences on human health. Those studies were conducted on beetles, birds, rodents, and nonhuman primates. Collectively, those experimental studies indicate that teratologic effects can occur only from exposure levels that cause biologically detrimental increases in body temperature. No reliable experimental evidence was found for nonthermal teratologic effects; rodents, mouse fetuses, and perinatal mice are more susceptible to such effects than rats. The primary confirmed effect in rats at high RFEMF levels was initial weight deficits in fetuses and neonates that decreased with infant growth. More generally from findings with pregnant mammals, exposures at RFEMF levels far higher than those permitted under the IEEE human exposure guidelines are necessary to reach or exceed cited experimental thresholds for maternal temperature increases. Some results indicated that the levels necessary to cause such effects in pregnant mammals could exceed those lethal to the dams. In a behavioral study of squirrel monkeys, no effects were observed on usual dam-offspring interactions or EEGs, but unexpected deaths of a number of offspring had occurred. However, this finding was not confirmed in a study solely on infant death using a larger number of subjects for greater statistical validity. Also reviewed were epidemiologic studies of various human populations considered to have been chronically exposed to environmental levels of RFEMF. Early studies on the incidence of congenital anomalies yielded no credible evidence that chronic exposure of pregnant women or of fathers exposed to RFEMF from nearby sources at levels below those guidelines would cause any anomalies in their offspring. The findings of studies on pregnancy outcomes of female physiotherapists occupationally exposed while treating patients with RFEMF were mixed, but taken collectively, the findings were negative. Bioelectromagnetics Supplement 6:S174-S186, 2003.

Thermal aspects of exposure to radiofrequency energy: Report of a workshop

“…A major review of RF-induced teratology (which was developed as part of the process of developing IEEE C95. concluded that a temperature threshold of 41.5 C exists for thermally induced birth defects in animals [32]. This conclusion was based on animal studies that observed no foetal abnormalities in the animals studied (mostly rodents) below this temperature.…”

The Sensitivity of Children to Electromagnetic Fields

“…31 Numerous studies have evaluated developmental effects of RF fields on mammals, birds, and other nonmammalian species. 53,54 These studies have shown clearly that RF fields are teratogenic at exposure levels that are high enough to cause significant increases in temperature. There is no consistent evidence of effects at nonthermal exposure levels, although only a few studies have evaluated possible effects on postnatal development using sensitive end points such as behavioral effects.…”

Thermoregulatory responses to RF energy absorption

“…Galvin et al [1986] found that rats exposed prenatally (3 h/day for days 5-20 of gestation) to 2450 MHz microwaves (10 mW/cm 2 , SAR 2-4 W/kg) weighed more than sham exposed animals at 30 days of age. Additional material concerning thermal effects on the embryo and fetus is provided in a separate white paper [Heynick and Merritt, 2003]. …”