Why should directional high-gain antennas be mounted higher than nearby structures?

Directional high-gain antennas focus RF energy into a tight, powerful beam. If mounted too low, this concentrated beam can easily penetrate nearby buildings, exposing the people inside to unsafe levels of RF radiation. Mounting the antenna higher than surrounding structures ensures the main RF beam passes safely over the heads of people in the vicinity. Distractors suggesting the goal is to prevent structural damage or receive fewer ground waves miss the primary regulatory and ethical concern of minimizing human exposure to electromagnetic fields.