ID Number		231
Study Type		In Vivo
Model		750, 1000 MHz (CW) exposure to Nematodes and analysis of development and fertility
Details		Nematode larvae (L1/L2 stage-synchronized) were exposed overnight to 750 MHz (CW) at 500 mWatts in a TEM cell held at 25 C. Exposure lead to an ~10% size increase (hypothesized to be due to a faster rate of progression through the life cycle) and a 30%-40% increase in the proportion of worms maturing into egg-bearing adults. The authors report that growth is decreased and egg-bearing maturation almost completely inhibited by non-RF heating to 28 degrees C for a similar time period. The authors also reported in an earlier paper on the induction of the heat shock promoter with RF exposure when the temperature was maintained at 25 degrees (ie; non-thermal exposure conditions) in a manner similar to non-RF heat induction observed at 28 degrees C. The authors interpret this data as indicating microwaves can cause a speeding up of programmed cell divisions and gene expression in a manner that is not explained by thermal effects. In a related study, several temperature sensitive mutants affecting either transmembrane receptors (TRA-2 and GLP-1) or nuclear proteins (PHA-1 and LIN-39) all show a wild type at 15°C, a mutant at 25°C, and a mixed phenotype at 21°C. Mutants were cultured at 21°C and exposed to 1 GHz (CW) for up to 90 minutes. The authors report more shifting in phenotypes of transmembrane mutants than nuclear protein mutants suggesting most thermal energy dissipated at the cell membrane. Further, when measures are taken to control subtle (0.2°C) heating, the observed mutant shifts are not observed.
Findings		Effects (only at thermal levels)
Status		Completed With Publication
Principal Investigator		Medical Countermeasures Dept, CBD, UK
Funding Agency		DERA, UK, MMF, MTHR (NRPB), UK, GSM Association
Country		UNITED KINGDOM
References		Guven, RG et al. Enzyme Microbiol Technol, (2006) 39:788-795 De Pomerai, DI et al. Enzyme and Microbial Technology, (2002) 30:73-79 Daniells, C et al. Mutat. Res., (1998) 399:55-64
Comments		Exposure should lead to a uniform field, although the effects do not appear to be uniform in the culture dishes in the TEM cell. Further, the effects of significant non-MW heating to 28 degrees are reported to result in a decrease in growth and inhibition of maturation to egg bearing adults, but the effects of more subtle heating (25.5, 26, or 26.5 degrees) are not addressed. In the most recent study, it is not clear that the 9 "experiments" performed were 9 seperate exposures, or simply replicate wells in a single or very few exposures.