Wildlife, especially birds, pose challenges. They prefer quiet, high places to live, but disturbing nests is illegal. Contact with droppings can also be harmful.

The Health and Safety Executive( HSE) recommends application of the hierarchy of control to prioritise the mitigation of EMF hazards. Eliminating the hazard is not normally possible, as we are trying to measure it and operators don ' t like their services being switched off. Substituting or reducing the hazard is an option, either reducing the transmitted power or using temporary equipment. Engineering controls such as screening / shielding may be an option, but can hinder access and affect the performance of radio equipment. Administrative controls such as signage draw attention to the existence of an invisible hazard, but there are numerous examples of sites where signage is missing, excessive or just plain wrong. Personal protective equipment( PPE) for EMF is limited, although gloves and boots can protect against unpleasant ' contact currents '. Radio Frequency( RF) suits containing stainless steel are available, but are rarely used because of impracticality and uncertainty about their effectiveness.

Down to earth In summary, EMF measurement at height is a niche area, but( nearly) always fascinating. If you find yourself in this position, always remember that EMF is not the only hazard; take steps to protect yourself and others from all the hazards. Be aware of surroundings which can influence the results. Choose the right measurement equipment for the task and know how to use it before you leave the ground. Above all, enjoy the view!

Carrying out EMF measurements on a 300 metre TV and radio mast in Wales

A common mitigation on radio sites is the RF personal monitor, which warns if field strengths become significant. Training is required to ensure correct use and avoid false alarms. Unlike ionising radiation, exposure is not cumulative, so we are only interested in the field strength ' here and now '.

The Control of Electromagnetic Fields at Work Regulations 2016( CEMFAW) lists Action Levels( ALs) which limit workers ' exposure and often form the basis of an EMF risk assessment. The article on page 31 of this issue discusses available guidance.

Performing EMF measurements around rooftop antennas

14 Radiation Protection Today www. srp-rpt. uk