"There is a very good possibility of weapons developed on the most recent advancements in nanotechnology in the next 10 years or so," said social scientist Juan Pablo Pardo-Guerra of the National University of Mexico in Mexico City. "Nanotechnology does have a lot of potential benefits, especially in terms of preventing chemical and biological attacks with more effective sensors, and with more effective means of containing chemical or biological releases.
"But it is important to keep in mind advances in nanotechnology that can enter the military sphere, in case some actually crystallize in the future," he added.
In talking about nanotechnology-enabled weapons of mass destruction, Pardo-Guerra set aside long-term and purely theoretical nanotechnological innovations such as self-replicating nanorobots. "There are other nanotechnologies that are much easier to implement in the near term," he explained.
Pardo-Guerra and colleague Francisco Aguayo, of the College of Mexico, outlined in Nanotechnology Law & Business Journal three ways in which nanotechnology could enable new weapons.
First, nanotechnology could make delivery of existing drugs more effective. For instance, pharmaceutical companies such as Elan in Ireland, Nanocarrier in Japan, and Solubest in Israel are working on nanoparticles that help the body absorb drugs. Elan noted up to half of all drug candidates show promise against their targets but are rejected because the body cannot absorb them due to poor solubility.
Nanotechnology could help make a series of drugs viable medicines, but also could, in principle, boost the power of compounds that once would have made ineffective chemical weapons.
"Nicotine is a poison in large amounts, something easy to produce. Delivering nicotine in lethal amounts is difficult but if you can develop something that could help nicotine go through the barriers the body has, you could make a weapon based on something that is not lethal," Pardo-Guerra said.
Second, by improving our knowledge of biology, nanotechnology could help find new ways to attack the body novel weapons inspectors might not recognize.
"For instance, with cyanide you have well-established means of synthesizing it, so you can follow the whole production process and detect it at an early stage. But you could design new agents that attack very specific functions in the body, say the central nervous system, and the amount of chemical you would need would be much less, so you wouldn't need a big industrial base to do that. It would be very difficult to trace," Pardo-Guerra said.
Third, nanotechnology could help make chemical and biological weapons controllable.
"There are some medical applications under development that involve nanocapsules that deliver a drug when activated by temperature, or go to tumors and heat up when beamed with microwaves. The strategic advantage of those weapons is that you can contaminate as many people as possible and then selectively activate them," Pardo-Guerra said. "This scenario is quite difficult, but not impossible."
Much remains unknown about to how feasible such novel weapons are.
"It's not clear what the costs of producing these are. They might not be economically viable," Pardo-Guerra said.
Microbiologist Mark Wheelis, of the University of California at Davis, told Nano World it is one thing to develop a chemical and deliver it to a willing recipient -- as with a prescription drug -- and another to develop a technology that could target troops or civilians over a large area without their consent in an attack.
"There is a streak of alarmism in the communities concerned about these things that isn't really helpful because it tends to alienate those knowledgeable about the threat and make otherwise sympathetic people more skeptical," said Wheelis, a member of the Washington-based Center for Arms Control and Nonproliferation's scientific working group on biological and chemical weapons.
"Still, I and most other people in the arms control field do feel nanotechnology has a lot of significant potential for use in novel weapons," he said. "This is somewhat a threat in the future, but we ignore emerging future threats at our very grave peril."
In the future, political and industry groups should consider initiating special training programs directed at helping future weapons inspectors get a quick capability to identify existing and emerging nanotechnologies that might pose a danger, Pardo-Guerra said. For instance, key developments in nanotechnology-based weapons might grow from otherwise benign fields such as law enforcement.
"There is a lot of research right now for non-lethal weapons for policing operations or riot control that are allowed under the chemical weapons convention. In the hostage situation in Moscow in 2002, the efficiency of the chemical weapons used by police there was very, very low, with a lot of unintended deaths with use of the agent. So there could be development in new delivery mechanisms for new incapacitating weapons that could quickly find other lethal uses," Pardo-Guerra said.
New regulations concerning potential use of nanotechnology in weapons of mass destruction are likely worldwide in the future, Wheelis predicted.
"The nanotechnology community can get ahead on this now and largely determine the nature of the regulatory apparatus if they take as one of their responsibilities the mapping out of harmful applications of nanotechnology and suggest rational and effective ways of reducing and mitigating that harm to the public sector," he said, and added if that responsibility is ignored, "the public and governments are going to wake up to the hazards and start calling for regulations anyhow. Any kind of regulatory approaches led by the community itself are almost certainly going to be better because they're technically informed."
Nano World is a weekly series examining the exploding field of nanotechnology, by Charles Choi, who covers research and technology for UPI Science News. E-mail: firstname.lastname@example.org.