A study was conducted in China to investigate the association between power line frequency extremely low frequency electromagnetic field exposure on selected neurobehavioral tests of workers inspecting transformers and distribution line stations.
The participants performed computer-based neurobehavioral tests (e.g., mental arithmetic, visual retention, auditory digit span, simple visual reaction time and pursuit aiming), which mainly assessed memory recognition accuracy, visual discrimination, short-term memory and cognitive performance.
|Reference group 1
|administrative staff and logistical personnel who were not authorized to enter the 500 kV and 220 kV zone
|workers who performed tour-inspection close to voltage transformers and distribution power lines
In 500 kV areas, electric field intensity at 72.0% of total measured 590 spots was above 5 kV/m (national occupational standard), while in 220 kV areas electric field intensity at 15.7% of total 701 spots was above 5 kV/m. Magnetic field flux density at all the spots was below 1,000 µT (ICNIRP occupational standard).
The neurobehavioral score changes showed no statistical significance between unexposed workers (group 1) and exposed workers (group 2). No significant changes in neurobehavioral tests were found among different age and seniority groups.
The authors concluded that in the present study no neurobehavioral changes were observed among workers with daily repeated exposure to extremely low frequency electric and magnetic fields.