Non-ionising radiation (NIR) is a form of electromagnetic radiation that does not have sufficient energy to remove electrons from atoms or molecules. It includes radio waves, microwaves, infrared radiation, visible light, and ultraviolet (UV) radiation.
The National Radiation Protection Authority regulates specified non-ionising radiation sources in accordance with the Atomic Energy and Radiation Protection Act, 2005 (Act No. 5 of 2005) and the Non-Ionising Radiation Regulations (Government Notice No. 126 of 2020). These regulations apply to non-ionising radiation sources operating within the frequency range of 0 to 300 GHz.
Sources of NIR
The following non-ionising radiation sources are regulated under the Non-Ionising Radiation Regulations:
a) telecommunications and broadcasting installations which are:
- TV antenna towers;
- radio antenna towers;
- cellular base stations; and
- microwave dish antennas;
b) Medical applications which are:
- magnetic resonance imaging (MRI); and
- diathermy and hyperthermia;
c) ultraviolet (UV) sun lamps; and
d) high power lasers.
Biological effects of NIR
Exposure to non-ionising radiation may result in biological effects depending on the frequency, intensity and duration of exposure.
Thermal Effects (Heating)
Radiofrequency and microwave radiation may cause heating of body tissues. Prolonged exposure at high levels can affect heat-sensitive organs such as the eyes and testes.
Nerve & Muscle Stimulation
Low-frequency electric and magnetic fields can stimulate nerves and muscles when exposure exceeds recommended limits.
Skin & Eye Damage (UV Radiation)
Ultraviolet radiation may cause sunburn, premature skin ageing, eye injuries such as photokeratitis, and may increase the risk of skin cancer following excessive exposure.
Interference with Medical Devices
Strong electromagnetic fields may interfere with the operation of implanted medical devices such as pacemakers and implantable defibrillators.
NIR Exposure Limits
Namibia has adopted the exposure limits developed by the International Commission on Non-Ionizing Radiation Protection (ICNIRP) to protect members of the public and workers from known adverse health effects associated with exposure to non-ionising radiation.
a) Public Exposure
Exposure limits for members of the public are designed to provide protection for people of all ages and health conditions.
For frequencies between 10 MHz and 300 GHz, the reference level for power density is: 10 W/m².
b) Occupational Exposure Limits
Occupational exposure limits apply to trained workers who may be exposed to non-ionising radiation during the course of their work.
For frequencies between 10 MHz and 300 GHz, the reference level for power density is:50 W/m².
Regulatory Requirements for Applicants and Operators
Owners and operators of regulated non-ionising radiation sources are required to comply with the Atomic Energy and Radiation Protection Act, 2005 and the Non-Ionising Radiation Regulations. The following are some of the key regulatory requirements:
Registration
- All regulated NIR sources, associated facilities and locations must be registered with the Authority in accordance with the Non-Ionising Radiation Regulations (Government Notice No. 126 of 2020).
Pre-Approval Required
- Operators must obtain prior approval from the Authority before installation or operation of NIR sources.
- Approval is conditional on demonstrating compliance with applicable regulatory requirements.
Establishing Exclusion Zones
- Operators must use mathematical calculations or appropriate modelling tools to determine exclusion zones for each antenna or device.
- These zones are areas where electromagnetic field (EMF) exposure exceeds ICNIRP limits and must be restricted.
- Calculated boundaries must be submitted to the National Radiation Protection Authority.
Implementing Safety Measures
- Reasonable and practicable engineering or administrative controls must be implemented to prevent access by workers and the public to areas where exposure may exceed limits.
- Controls include barriers, signage, and access restrictions.
