摘要
Owing to health and security hazards posed by concentration of EMR (electromagnetic radiations) from wireless transmission devices such as antennas and WiFi, it is time for building specialists to consider EMR shielding in general designs. Such a venture needs understanding of shielding behavior of various building materials in their isolated and combined forms. While shielding properties of several industrial materials are known, much remains to be understood from traditional materials. This article contributes to the knowledge of SE (shielding effectiveness) of the latter materials. It has tested the buildings of the 19th CE STZ (Stone Town of Zanzibar). The coral stones, mud, and mangrove pole buildings of this historic town were found to be effective in shielding the radiations, nearly the same as renowned buildings of the Roman Empire.