Micro Defense (CTP1)

Micro Defense is a city improvement in Civilization: Call to Power.
==Effect==
The Micro Defense protects the player from biological and nanoviral attacks. For those within the city, the filter appears as little more than a vent. From outside however, the filter's powerful machinery stands witness to the protection that it provides.
== Great Library entry ==
During the 20th century military scientists developed anthrax, plague, and Ebola strains for military use. Packed into a dry, powdery form, these viral/bacterial agents threatened human health until the development of the artificial womb and the Micro Defense. Weeding out dangerous chemical agents from human environments, the membrane alerted scientists to newly engineered biological threats.