On November 3, the House Homeland Security Committee held a hearing on efforts to guard against bioterrorism in the United States. Former Senator Lieberman, former DHS Secretary Tom Ridge, and Dr. Leonard Cole, Director of the Terror Medicine and Security Program from Rutgers Medical School, addressed the prominent threat of bioterrorism (which my fellow Security Debrief contributor David Olive wrote about in a recent post).

In what should be a highly noted hearing on a strong proposal to increase our nation’s fight against terrorism, one representative noted what might be the most alarming progression of technology in bioterrorism: the use of an unmanned aerial vehicle (UAV, or more commonly, “drone”) to deliver a biological weapon. Representative Duncan Hunter (R-CA) spoke about the ease with which a bio-weapon could be delivered via drone by way of the U.S.-Mexico border. Drones are already being used for a range of activities, such as delivering packages for Amazon, monitoring poachers of endangered animals on African reservations, and even for herding sheep in Ireland. For all their utility, drones are also posing new security threats, such as the risk of unmanned aircraft flying over stadiums or intercepting commercial airplanes’ flight paths.

More recently, and as Representative Duncan cited, drones have been used to smuggle drugs over vulnerable borders. If federal law enforcement is having a hard time detecting drones flying over the border with drugs, what makes us think we would have the capability to detect a drone that would carry a bioterrorism agent? Well, we can’t. At least not right now.

Drugs, though not needing to be dispersed like a bioterrorism agent, are similar in terms of ease of transport. Last year, the Drug Enforcement Administration said that drug cartels used drones at least 150 times to transport illicit substances across the U.S.-Mexico border. As Sec. Ridge pointed out during the hearing, there are five theaters important for homeland security: land, sea, space, cyber, and air.

Air is a cardinal factor in bioterrorism because of how an agent travels. Finding the right weather, wind speed, and climate all have effects on how successful a pathogen can spread. For the most part, this, paired with the difficulty in acquiring a biologic agent, frustrates terrorist groups’ bioterrorism aspirations. Drones directly bring the “air” to the bioterrorism sphere.

Bioterrorism is a low probability, high-impact occurrence. Indeed, what is arguably the only example of a successful biologic attack is the case of Aum Shinrikyo’s release of sarin gas in the Tokyo subway in 1995. The attack killed 12 people and affected the health of 12,000 more. Today, the difficulty with detection methods and coupled with the advent of low-cost drones could make transporting liquid agents or dispersing airborne pathogens fairly easy.

Smaller, micro drones that are currently being developed would be almost undetectable and could deliver pathogenic microorganisms. Larger drones would be able to spread larger liquids or aerosols. As Sec. Ridge stated, this becomes less of a preventative factor when terrorists are recruited, possibly bringing prior experience from the medical or chemical fields. With splintered terrorists groups like ISIS continuing their vicious recruitment of vulnerable young people and troubled adults, the likelihood of someone with access to a pathogenic strain or relevant experience also increases. Doesn’t bode well for bioterrorism prevention.

DHS needs to look at this issue from two angles. First, we need an effective bio-detection program, and we don’t have one. Second, we need drone detection and disruption programs. While this necessarily includes the participation of other federal agencies, it was a low-probability, high-impact event that served as the catalyst for the Department’s creation. This issue is squarely in DHS’ court—or skies, as it were. Let’s hope DHS finds workable solutions and fast.