High-voltage power lines and transformers generate strong low-frequency magnetic fields (ELF) that can penetrate walls and extend far into nearby buildings. Always detect first with the Latnex AF-5000 or a magnetic field meter to measure field strength across different areas of your home or property.
Unlike wireless sources, these magnetic fields cannot be blocked with standard EMF fabrics or paints. Instead, reduce exposure by increasing distance from the source wherever possible, and use specialised magnetic shielding materials such as MuMetal or Magnetic Shielding Foil on walls facing the power lines.
For long-term mitigation, consider rearranging sleeping or working areas to lower field zones and verifying results periodically with accurate measurements.