Over recent years, the levels of electromagnetic radiation have increased substantially particularly in urban neighbourhoods worldwide. Across the world, there is still a growing demand to establish more wireless networks for smartphones and other online mobile devices. The trend of investing in wireless communications is reflected also in the demand for more transmitters (base station antennas). These antennas constantly emit microwave radiation into their surroundings. In 2011, The World Health Organization classified radio frequency (RF) radiation as possibly carcinogenic to human beings (class 2B).

What makes the development problematic from the legal point of view, is that legislation has not kept pace with technological development. There is a lack of legislative norms guiding the siting of microwave transmitters in our environment. There is a need to find a balance between radio technological reception and radiation safety. The exposure is unequal because the RF radiation levels might significantly differ e.g. between dwellings or workplaces.

The precautionary principle has been established as an official principle in the international environmental law, the European Union legal system, and many international treaties and declarations. It is applicable in cases which involve uncertainty as to the seriousness and scope of the risk. There is also a procedural dimension to the precautionary principle, demanding that citizens should be allowed to participate in decision-making concerning their environment.

The safety limits of base stations differ even between the EU member states: Most countries rely on ICNIRP (International Commission on Non-Ionizing Radiation Protection) guidelines although they have been criticized to be based on insufficient scientific evidence and to serve the interests of industry. Therefore, several countries or regions have implemented substantially lower safety limits. However, the industry contends that even the ICNIRP guidelines include the precautionary approach as such.

The authors conclude that the precautionary principle has not been sufficiently paid attention to when cellular network systems have been established in vicinity of locations in need of special protection, such as homes, kindergartens, or schools. More public debate, legal norms, and flexible environmental conflict management methods such as mediation are required to deal with this emerging global issue.