A quick and easy method for checking compliance of multi-frequency magnetic fields with ICNIRP's guidelines.

Area of Science:

• Biophysics
• Electromagnetism
• Public Health

Background:

• Assessing human exposure to complex extremely low frequency magnetic fields requires sophisticated methods to comply with ICNIRP guidelines.
• Current methods are complex and often necessitate specialized equipment, limiting the use of common broadband instruments.

Purpose of the Study:

• To develop a simplified method for checking compliance with ICNIRP guidelines for multi-frequency magnetic fields using broadband instruments.
• To establish a practical test for determining if further, more complex measurements are necessary.

Main Methods:

• Determining the spectral distribution of magnetic fields that maximizes exposure metrics.
• Estimating an effective reference level for broadband magnetic field values based on worst-case spectral distributions.
• Validating the method with a case study involving 50 Hz and 60 Hz magnetic field components.

Main Results:

• A simplified method allows compliance checks using only broadband instruments when source frequencies are known.
• For a worst-case scenario with 50 Hz and 60 Hz components, the effective broadband reference level was found to be 64 µT for general public exposure.
• The method is conservative for incoherent fields and very conservative for coherent fields.

Conclusions:

• The proposed method offers a quick, easy, and resource-efficient way to initially assess compliance with magnetic field exposure guidelines.
• It effectively screens cases, indicating when more detailed measurements are required, thereby saving time and costs.