Radiofrequency electromagnetic field effects on green roof ecosystems: An unexplored topic

In recent decades, mobile communications technologies have been adopted at an unprecedented pace, leading to a rapid increase in the exposure of living organisms to artificial radiofrequency electromagnetic field (RF-EMF) emissions. This exposure is typically much higher on rooftops in dense urban areas where antennas are located, compared to ground level in those same areas. The recent deployment of wireless infrastructure on urban rooftops has coincided with the expansion of green roofs in cities. This indicates that RF exposure is a factor to consider in the planning and maintenance of green roofs. In this paper, we evaluate RF-EMF exposure levels on green roofs situated near base station antennas. Based on this evaluation, we predict potential responses at both the population and ecosystem levels to RF exposure. We conducted a structured two-stage literature review. In Stage 1, we performed a narrative synthesis of empirical RF-EMF measurements on urban rooftops, covering the 0.7–3.8 GHz frequency range. We searched IEEE Xplore, Web of Science, and Google, and retained 20 peer-reviewed and institutional publications containing original measurement data published from 2001 onward. In Stage 2, we conducted a thematic synthesis of published evidence on RF-EMF biological and ecological effects in plants and insects — the taxonomically dominant groups in green roof ecosystems. We searched Web of Science, PubMed, Google Scholar, and the EMF-Portal, retaining 34 studies that satisfied criteria for publication quality, precision of exposure characterization, and relevance of exposure conditions to those determined in Stage 1. The two stages are linked analytically: the exposure range identified in stage one defines the evidence boundary for the bioeffects synthesis in Stage 2. Our research yielded an entirely new ecological interpretation of the evidence on physiological RF-EMF effects in plants. It suggests that chronic stress signal induced by RF-EMF may cause reduced seed production and a shift in resource allocation towards clonal growth. This can lead to lower seedling recruitment and decreased genetic diversity, which may negatively impact the long-term resilience of a green roof ecosystem. There has been no empirical research or specific legislation addressing the issues discussed.