Developmental Effects Of 900MHz Microwave On Chick Embryos

Cellular phones are rapidly gaining popularity and yet little is known about the health hazards of the microwave by use of the phones. The public have become increasingly concerned about the health impact shown by the non-thermal effect from animal experiments and epidemiologic studies.Objective:To study with the chick embryo model for biological effects of 900MHz continuous microwave and to provide with basic data for exploring mechanisms of the adverse effects of microwave from celluar phones.Metheods:(1)Irradiation method: Chick embryos of three dose groups were exposed to 900MHz continuous radiofrequency fields from 5thday to 20th day of incubation, with 1h, 2h and 4h per day. The power density was 1.5mW/cm2. (2)Measurement of physical parameters: A noninvasive technique of recording electrocardiogram (ECG) from chick embryos was established. Heart rates and QRS intervals were determined by the ECG. Ultraweak luminescence of embryos was measured by the UltraWeak Luminescence Analyzer. Besides, spontaneous movements and weights of hatched chicks were recorded, so was the hatching rate of chick embryos. (3)SOD(superoxide dismutase) activity in heart and brain tissue was dectected by method of xanthine oxidase- hydroxylamine. Reverse transcription polymerase chain reaction(RT-PCR) was conducted to examine levels of Hsp70 mRNA in heart and brain tissue.Results:(1)On the 13th day of incubation, the SOD activity in brain tissue of 2h irradiation group was significantly decreased compared to the control group, so was the SOD activity in heart and brain tissues of 4h irradiation group. Levels of Hsp70mRNA in heart and brain tissue of 2h and 4h irradiation group were found significantly increased. However, on the 20 th day, the SOD and ODC activity and level of Hsp70mRNA did not change obviously(.2)Compared to the control group, heart rates of three irradiation groups showed no changes on the 15th day. In 1h irradiation group on the 17th day and 4h irradiation group on the 20th day, the heart rate of chick embryos decreased significantly.(3)Though ultraweak luminescence of 1h and 2h irradiation group was decreased significantly on the 16th day of incubation, no distinct changes were found on the 13th day and the 20th day.(4)The spontaneous movement of chicks of 1h and 2h irradiation group increased significantly on the 1st day after hatching, and turned to normal on the 10th day. The weight of hatched chicks significantly increased in 1h and 4h irradiation group on the 10th day,but not on the 1st day.Conclusion: The results proposed a possible window effect of microwave on the chick embryos. The imbalance of antioxidation sytem and the heat shock reaction induced by the microwave could get recovery along with the development of chick embryos.