ID Number		221
Study Type		In Vitro
Model		915 MHz, 1.2, 7.7 GHz exposure to isolated primary lymphocytes and cell lines and analysis of chromosome aberations, micronuclei, DNA breaks, and proliferation
Details		Human lymphocytes were exposed to 7.7 GHz microwaves (CW) for 10, 30, & 60 minutes at power densities of 0.5, 10, and 30 mW/cm2 and a constant temperature of 22 C using a reflex Klystron and analyzed for chromosome aberrations. The authors report statistically significant increases in chromosome aberrations and micronuclei formation. In a similar study using V-79 Chinese hamster lung cells, 7.7 GHz exposure as above reduced colony formation and increased chromosome aberrations in a dose dependent manner. Exposure also resulted in decreased 3H-thymidine uptake and prevented cells from entering into the S phase of the cell cycle. In a study of lymphocytes isolated from individuals occupationally exposed to X-rays, vinyl chloried, or microwaves, exposure to 1250-1350 MHz (CW) at power densities between 10-20 mW/cm2, lymphocytes obtained from vinyl chloride-exposed workers showed both clastogenic (chromosome damaging) and aneugenic (chromosome reducing) anomalies, while those obtained from workers exposed to X-rays or microwave radiation showed only clastogenic anomalies. In later studies, the group examined the effects of honeybee venom and report it has a protective effect against DNA damage (as analyzed via Comet assay) due to 915 MHz (CW) exposure at 0.6 W/kg in primary cultures of rat lymphocytes. The authors suggest the bee venom may act as a free radical scavenger.
Findings		Effects
Status		Completed With Publication
Principal Investigator		Inst Med Res & Occup Health, Croatia - vgaraj@imi.hr
Funding Agency		Private/Instit.
Country		CROATIA (local name: Hrvatska)
References		Gajski, G et al. Int J Toxicol, (2009) 28:88-98 Garaj-Vrhovac, V et al. Mutat. Res., (1992) 281:181-186 Fucic, A et al. Mutat. Res., (1992) 282:265-271 Garaj-Vrhovac, V et al. Mutat. Res., (1991) 263:143-149 Garaj-Vrhovac, V et al. Mutat. Res., (1990) 243:87-93 Garaj-Vrhovac, V et al. Periodicum Biologorum, (1990) 92:411-416
Comments		For initial human lymphocyte studies, chromosome aberrations increased with exposure (1.5% of controls, 5.5% of cells exposed 10 mW/cm2 for 10 min; 4.9% of cells exposed to 30 mW/cm2 for 10 min; 6.1% of cells exposed to 30 mW/cm2 for 30 min; 7.2% of cells exposed to 30 mW/cm2 for 60 min) in colchicine-arrested metaphase spreads from PHA-stimulated lymphocytes. Micronuclei increased with exposure (0.9% in controls, and 1.4, 3.6, 4.0, 4.4, and 6.8% of cells exposed to 0.5 mW/cm2 for 30 min, 10 mW/cm2 for 30 min, or 30 mW/cm2 for 10, 30 or 60 min, respectively) (only the latter 2 exposures were statistically different from controls at p<0.05 to p<0.001). For V-79 hamster cells, exposure for 10-, 20-, 40- and 60-min exposures at 0.5 mW/cm2, resulted in colony counts of 90, 84.5, 76.2 and 60.4% of controls; at 10 mW/cm2 CFUs were 88.6, 64.8, 55.7 and 49.2% of controls. Statistically significant increases in chromosome aberrations were observed following exposure at 30 mW/cm2 (chromosome aberrations in 1.7, 4.8, 6.3 and 15.0% of cells following exposure for 0, 15, 30 or 60 min, respectively). Micronuclei induced per 1,000 cells were 0.016 +/- 0.016 in controls, 0.043 +/- 0.042 following a 15 minute exposure at 30 mW/cm2 (p<0.02); 0.50 +/- 0.49 following a 30 minute exposure at 30 mW/cm2 (p<0.05); and 0.073 +/- 0.073 following a 60 minute exposure at 30 mW/cm2 (p<0.05).