Councils manage buildings where people and equipment are potentially exposed to electromagnetic fields, known as EMFs. Sources of EMFs include substations, switchboards, and mains cables.
These can radiate significant strength for several metres in any direction. Brick walls, or concrete floors do nothing to stop them. EMFs can be evident by their interference with computers, causing screens to shimmer. Moreover, the advent of the computer has increased the visibility of EMFs However, EMF’s can be present without being ‘visible’, leading to a situation of potential health and safety claims.
Employers and building owners should conduct a risk assessment in relation to EMFs. The use of gaussmeters can assess areas around known sources, or expose hidden sources. Designers of new buildings should specify their requirements in relation to EMF performance limits.
Acceptable limits of EMF radiation are the subject of a wide range of opinions. The International Commission on Non-ionizing Radiation Protection Guidelines specify 5,000 milliGauss (mG), as the limit for occupational exposure.
“In performing their Risk Assessment, Councils need to take advice as to what criteria to adopt,” said Ken Brookes, a civil engineer who specialises in assessment and remediation of emf issues.
He also said that if significant levels of EMFs are found there are three main responses.
- Prudent avoidance – relocating people and computers away from the affected area.
- Electrical audit – checking circuits for leakage to neutral, phase imbalance or other correctable faults.
- Shielding – EMF suppressing material can be installed between the source and the target area.
For further information contact Ken Brookes on (03) 9876 2496, mobile 0419 428 039 or email winabi@eisa.net.au
