Three groups were examined (n=20 per group): 1) exposure for 24 hours, 2) exposure for 72 hours and 3) exposure for 7 days. For every exposure group, a control group was (also n=20 per group) sham exposed for the same time span. The cockroaches were exposed together but examined individually.
|Chamber||cockroaches were placed in a cylindrical glass chamber (10 cm x 7.5 cm; volume 0.589 l) without movement restriction|
|Setup||magnetic field was generated by one coil with a diameter of 20 cm; maximum inhomogeneity was 10% inside the coil; temperature was monitored using thermocouples mounted under each exposure system|
|Sham exposure||A sham exposure was conducted.|
The escape latency was significantly longer in exposed cockroaches compared to the corresponding sham exposed animals. Additionally, the lipid peroxidation was significantly increased in all exposed cockroaches compared to the corresponding sham exposure, while the glutathione level was only significantly decreased after 7 days of exposure when compared to 7 days sham exposure.
The authors conclude that 50 Hz magnetic fields could impair heat perception in cockroaches and influence the oxidative balance.