To study the possible effect of 60 Hz magnetic fields as promoters of brain tumors initiated by ethylnitrosourea (ENU) in rats.
120 mated rats were divided into six different groups and exposed in utero on day 18 of gestation to a single intravenous dose of either saline (control group, group I), or ENU (10 mg/kg; groups II-VI). A total of 480 offspring was used. The offspring in group II were given no further treatment while the offspring in groups III-VI were exposed to four different intensities of magnetic fields including sham exposure (from the age of 4 weeks to the age of 32 or 42 weeks).
| Exposure | Parameters |
|---|---|
|
Exposure 1:
60 Hz
Exposure duration:
continuous for 21 h/day from the age of 4 weeks to the age of 32 weeks or 42 weeks
|
|
animals were divided into 6 groups: i) exposure in utero on day 18 of gestation to a single, intravenouse dose of saline ii)exposure in utero on day 18 of gestation to a single, intravenouse dose of ENU 10 mg/kg iii) exposure in utero on day 18 of gestation to a single, intravenouse dose of ENU 10 mg/kg + sham EMF exposure iv) exposure in utero on day 18 of gestation to a single, intravenouse dose of ENU 10 mg/kg + exposure to 5 µT v) exposure in utero on day 18 of gestation to a single, intravenouse dose of ENU 10 mg/kg + exposure to 83.3 µT vi) exposure in utero on day 18 of gestation to a single, intravenouse dose of ENU 10 mg/kg + exposure to 500 µT
| Frequency | 60 Hz |
|---|---|
| Type | |
| Exposure duration | continuous for 21 h/day from the age of 4 weeks to the age of 32 weeks or 42 weeks |
| Additional info | rotating magnetic field |
| Exposure source |
|
|---|---|
| Setup | four square coils |
| Sham exposure | A sham exposure was conducted. |
| Measurand | Value | Type | Method | Mass | Remarks |
|---|---|---|---|---|---|
| magnetic flux density | 5 µT | - | calculated | - | - |
| magnetic flux density | 83.3 µT | - | calculated | - | - |
| magnetic flux density | 500 µT | - | calculated | - | - |
Neurogenic tumors were found in all the ENU-treated groups. The tumor incidence of the ENU group at 32nd and 42nd week necropsy was higher than that of the control group.
However, there were no differences in the tumor incidence between the sham exposure group and "ENU + magnetic field" exposure groups.
In conclusion, there was no evidence that exposure of offspring to 60 Hz at magnetic field strengths up to 500 µT promoted ENU-initiated brain tumors in rats.
This website uses cookies to provide you the best browsing experience. By continuing to use this website you accept our use of cookies.
