  This paper proposes a method for reducing {third-party} exposure to
electromagnetic fields (EMF) by exploiting the capability of a reconfigurable
intelligent surfaces' (RIS) to manipulate the electromagnetic environment. We
consider users capable of multi-beam communication, such that a user can use a
set of different propagation paths enabled by the RIS. The optimization
objective is to find propagation alternatives that allow to maintain the target
quality of service while minimizing the level of EMF at surrounding
non-intended users (NUEs). We provide an evolutionary heuristic solution based
on Genetic Algorithm (GA) for power equalization and multi-beam selection of a
codebook at the Base Station. Our results show valuable insights into how
RIS-assisted multi-beam communications can mitigate EMF exposure with minimal
degradation of the spectral efficiency.
