A 
system is provided for responding to chemical, biological and / or nuclear attacks in large areas such as cities, states and nations. The 
system protects the public before significant 
exposure occurs, utilizing a preventive approach rather than a purely reactive approach. Modeling may be conducted to selectively position sensors for the on-going collection of real-time detection data, such as contaminant types and concentrations, weather conditions, 
terrain data, dispersion data and the like. The detection data is compared to 
background data and modeled data to detect unsafe contaminant levels and immediately activate a 
response system. The integrated 
modeling and simulation component may function to interface with real-
time data from the sensors providing integrated real-time plume depiction, prediction, and 
verification, as well as real-
time response and mitigation. This is testable and serves as an advanced redundant 
scientific control. The 
response system may implement a variety of measures, including, but not limited to, medical response procedures for 
emergency rooms and hospitals, warning alarms, instructions for personal protection, sealing of buildings, introduction of 
positive pressure in buildings, and introduction of clean air in confined spaces. During the 
response period, actual affects of the contaminant release may be determined, such as symptoms developed by people, animals and plants, treatments given to patients, medication consumption, assessments of environmental damage and remediation thereof, etc. The response to the contaminant release may then be modified based on the determined actual affects of the contaminant release.