BIOLOGICAL TERRORISM IN INDOOR ENVIRONMENTS
“A fast-moving airborne pathogen could kill more than 30 million people in less than a year.”
– Bill Gates
In the age of permanent security challenges and global risks, the idea of terrorism seems like a daily menu for the concerned citizens around the world. This seed of evil is everywhere and it is just a matter of time when it will be multiplied so much to break all the known borders and to turn the civilization into the chaos. Nevertheless, the biological terrorism is the worst form of terrorism itself because it is non-conventional and it abuse all attributes of stealth warfare. If you have to deal with biological agents that cause some of the worst diseases ever, you are aware that you do not see them and you are not sure if you are infected, if you have any chance to survive and when you will die. The all questions are opened and the microbes reply on them, as they want.
The biological terrorism is a special kind of asymmetric war that includes abuse of biological agents (bacteria, virus and toxins) against the people, animals or nature with the final goal to disturb the state and its system, making damages and delivering fear among the potential targets. Once it is picked up and realized as the powerful war tool, the dangerous germ is unstoppable. This depends on its organic structure, killing effectivity and way of spreading but wisely chosen biological agent could cause the epidemic and pandemic as well as the civil unrest and brutal martial law. The biological weapons is very cheap to be produced and disseminated but very expensive to be neutralized.
There are no many doubts that biological weapons will be integrated into the new age concept of war. The state has no possibility to build an active protective counter biological terrorism shield and to empower its sensibility against the future attack of microbes. First, the enemy is not known. That could be everyone, fanatical Islamic terrorist group or lone wolf psychopath with voices in the head. The security service and the levels of intelligence cannot recognize the threats on time no matter how developed they are. The biological agent is always one-step forward. When it is already done, then it is already late.
The most dangerous dimension of biological terrorism scenario is strike on indoor environment, which further means diversion of ventilation and air handling systems in the buildings and facilities. Just the thought that some hazard microbe could be infiltrated in the air installation of the building with more than 100 occupants, brings goosebumps. One study has been made on the engineering review of the architectural weakness of the building to be abused for a biological invasion:”An important step in the aftermath of the release of a harmful biological agent is to identify how extensively that agent might have spread within a facility. Many areas could be contaminated indirectly because of the way air circulates within the building and at its periphery. Biological agents, such as Bacillus anthracis spores, can behave as particulate solids or as droplets, thus allowing for extensive modeling. However, because those agents are living organisms, their characteristics can vary as can the effects they have within a population. An agent used in an attack could change over time as it is suspended into the air, settles onto surfaces, and is resuspended and its properties could alter under different environmental conditions. Some airborne agents (those without fast settling velocities) will be distributed and diluted by mechanical ventilation systems. Some will attach to surfaces, but later could be reaerosolized or resuspended.Contaminants move in air in response to pressure gradients. Mechanical air-handling systems in many buildings use fans to create pressure gradients that move air through ducts, plenums, and exhaust shafts. The pressure gradients, the buoyancy of heated air, and wind flow around a structure allow for the infiltration or exfiltration of air, which provides conditioned air to the occupied areas.”
The way the agent will be activated and spread is related to the protective capacity of the building and its tightness, the resistance to infiltration of outside air, the stability of its air transport system, location and degree of physical security. The last indicator is also very important since it can determine the others. In the case of established video monitoring and control of visiting outsiders, the risk is automatically reduced. The modern security engineering offers passive and active measures against the biological attack in indoor environment. The passive have been used for years and that is a set of architectural features, mentioned physical security and air filtration. They are very effective but they have vulnerabilities:” These vulnerabilities fall into two categories. First, occupants could be exposed to an unidentifiable threat that goes untreated and for which therapeutic options decrease with time. An example would be an indoor release of a biological threat agent with an incubation period of days. Second, occupants could be exposed to an unidentifiable threat that is fast-acting, such as a chemical threat agent, released inside the building space. (Note that passive measures could be used to protect occupants from outside release, but only some occupants could be protected from inside release through passive compartmentalization methods).” That was a main reason for active measures to be created and implemented in every new security engineering strategy. The active measures are based on HVAC( heating, ventilating, and air conditioning system) and the accepted building mechanical changes. There are natural and mechanical methods of ventilation. The air can be supplied through windows or through the organized system of HVAC that uses fans and duct work. The majority of private houses follow the natural method of ventilation – 1 full air exchange every 2 hours while the public and commercial buildings have mechanical HVAC systems – 2 full air exchange per hour. One engineer wrote that in the emerging cases, the exchange is modified:”Minimizing the rate of air exchange with the outside will keep the indoor concentration as low as possible for as long as possible. Normal operation of HVAC will exhaust some building air and pull in some outdoor air. If the outdoor air is contaminated, the HVAC system will spread the contamination throughout the building. Air exhausted from the building by exhaust fans will also be replaced by outdoor air. Shutting off HVAC fans and exhaust fans will help minimize the air exchange with the outside.”
The ultra-modern security HVAC systems have special ventilation codes and sensors that could detect the possible danger and remove it or block it through the air filters. Unfortunately, that is not a rule but an exception and it is a typical for political, biomedical and military facilities. We could count on four levels of protection. The first one is LP1 – Low Level Passive Protection or basic passive protection of building and its occupants without real methods for defense but it is still very advanced in response on biological infiltration. The second is LP2 (High Level Passive Protection) and it is more developed to treat the problems but it is still not in the area of active measures and protection. On the third place is LP3 (Low Level Active Protection) that combines basic passive and active methods of security against the ventilation contamination. It is known as a super system of detection of threats and their identification. The last one is LP4 (High Level Active Protection) that is one perfect set of methods able to protect the facility and its occupants. With this system of defense, the targeted object is capable to recognize the threat, treat the exposed victims and minimize the impact and its damage. LP3 and LP4 have elements of the LP1 and LP2 so they could be considered as the highest solutions for the effective security engineering strategy.
The time we live in is a full of security problems that could disfigure our reality. The biological terrorism attack in indoor environment is one of the worst plots against the humanity since the people are very fragile in their own homes and privacy. This is why is so important to implement and enhance some of the levels of protection in private and commercial buildings and to check them regularly. The system that is failed on the checking routine should be and must be replaced with the one that is functional more than 100 %. At the end of the day, human lives are imperative.