On June 27, 1994, members of the Aum Shinrikyo cult drove a converted refrigerator truck into the quiet residential neighborhood of Matsumoto, Nagano, Japan, and parked it in a secluded parking lot hidden by trees. Determined not to lose in the real-estate lawsuit they were embroiled in, the group released a deadly cloud of sarin gas near the dormitory where the three judges presiding over the case were staying.

Pushed by a light breeze, the lethal haze floated over the dormitory, a number of private homes and a mid-rise apartment building. Hundreds of people were exposed to the gas through open doorways and windows. Seven people died in a very short time and 500 others had to be rushed to local hospitals for treatment.

In the United States, the “Amerithrax” attacks in 2001, where anthrax spores were mailed to a few news media offices and two Democratic senators, killed five people and infected 17 others.

Many terrorist attacks over the last few decades have specifically focused on attacking people within buildings and disrupting everyday operations. Every type of building is equally at risk. Toxic agents can be released into the building’s air intake, inside the building or in the environment around it. Injuries and loss of life aren’t the only hazards; effectively decontaminating the structure can be a very time-consuming process posing great risk to the clean-up crew. In spite of these dangers, surprisingly, there seem to be very few solutions available that can adequately protect buildings and people in them from serious harm.

A new look at HVAC

“No universal system exists that would be applicable to any building heating, ventilation and air conditioning (HVAC) design, any occupancy, any hazard type and level, with reasonable operational requirements that’s available at an affordable price,” according to Edward Morofsky, a building energy and control engineering specialist for Government Services, Canada. “But there are many components and designs that do provide some protection against specific hazards. Normal office buildings need a real-time monitoring system that detects most hazards as they are occurring, an HVAC ventilation system that handles all of the air entering and leaving the space, effective countermeasures that lessen or eliminate the hazard and training of communication with building occupants to take appropriate steps that have been rehearsed before hand.”

Currently, buildings are either not monitored at all for chemical toxins and biological agents because of prohibitive costs or they are monitored only for certain specific agents. The greater the number of agents monitored, the more expensive it becomes. It simply isn’t feasible to continuously monitor the presence of toxic agents both indoors and outdoors.

Consequently, the current state of building protection is pretty dismal. Accidental chemical spills are normally reported by individuals, while terrorist attacks are typically discovered on an ad hoc basis after terrorists have delivered an initial blow.

Researchers at the University of Saskatchewan, Canada, hope to address this critical need by constructing a truly comprehensive system that can completely and continuously protect a building from all chemical and biological warfare. The Early Warning and Response system (eWAR) is an entirely new ventilation system that’s being designed to create ‘immune buildings.’ Rather than looking for specific agents, eWAR works by establishing a baseline of normal air rhythms within a building that forms the “building’s pulse.” The release of an agent is detected within seconds as an irregularity in the pulse, enabling the system to instantly initiate neutralization measures for all types of chemical and biological agents and activate appropriate security measures.

“Let me make a simple comparison here,” Janusz Kozinski, lead researcher and dean of the College of Engineering at the University of Saskatchewan, Canada, wrote to HSToday. “HVAC ducts are transporters of life-blood, that is, air, to the building’s occupants, similar to the veins and arteries of a human body. In a human body, the heart senses the irregularities of blood streams through a perturbation mechanism in pulsation rhythms of heartbeats. Levels of such perturbations are quantified against baseline norms of pulsation rhythms and corrective actions in the form of electrical signals and are generated accordingly. In a similar metaphor, HVAC systems in buildings should have several integrated pulsation-perturbation-monitoring (PPM) systems that sense and signal irregularity of in-duct air. Air characteristics such as flow pulsations should be continuously compared with normal day-to-day baselines. Any out-of-norm pulse in the air characteristics (i.e., high particle or volatile organic counts) should activate a control response to assure the delivery of ‘normal air’ to building occupants.”

Consisting of a series of building ventilation systems integrated with several modules for agent detection and neutralization, eWAR monitors air quality continuously, acting only when it senses an irregularity. Site-specific responses are immediately activated within three seconds. A damper diverts the contaminated air back to the exterior. High-pressure water jets are released, air filters are activated, ultra-violet light irradiating devices are triggered and the HVAC system is manipulated with pressurization and purging techniques. Relevant signals are sent wirelessly to a central command station only if necessary. Security personnel at the command center can communicate with all of the detectors, sensors and response actuators.

The key advantage here, according to Kozinski, is that eWAR initiates a response and acts to contain and neutralize the threat even on the suspicion of a release. Detecting the presence or absence of a hazardous agent, its concentration, occurs in parallel and appropriate signals are sent to the command center. Since the system takes preventive measures and works to neutralize the threat as soon as it is alerted, it reduces potential exposure time drastically, giving emergency responders the extra seconds they need to respond before it’s too late.

“Think of it as a complex fire alarm for industrial chemical spills, airborne diseases and biological warfare strikes on vulnerable public spaces,” said Kozinski. “Currently, the system sends relevant signals to the ‘central command’ where decisions with respect to informing people and evacuation are taken. eWAR will react to a threat, start initial response and alert authorities simultaneously, and then let further responses be guided by the authorities.”

The system can also be used to contain outbreaks of diseases, such as tuberculosis, chickenpox and others, before they spread through the air vents.