Beyond the Molecular Frontier: Challenges for Chemistry and Chemical Engineering (2003)

Science and technology have always played a major role in national security, particularly to arm and protect our military forces. The September 11, 2001, attack on our country has directed tremendous attention to science and technology and ways that it might be mobilized for national security and homeland defense. The very real threat of future acts of catastrophic terrorism has become a significant force for shaping research directions in chemistry and chemical engineering. The most critical needs for national security are inherently chemical capabilities, such as the means to analyze and detect threats by providing intelligence and warning, and the ability to respond to an attack by mitigating damage and decontaminating a site. Achieving these goals will require concerted basic and applied research in chemistry and chemical engineering.

The personal security of our citizens also benefits directly from science and technology. Our police forces are equipped with light, strong bulletproof vests made of modern synthetic materials, and fire rescue personnel wear protective clothing made from temperature-resistant polymers. The smoke detectors and carbon monoxide detectors in our homes are based on chemical processes that detect dangerous substances. Personal security is enhanced in the broadest sense by water purification and by the chemical testing procedures that assure us of clean water and food.

Chemical science and technology must contribute to the enhancement of national and personal security by providing fundamental understanding and new developments—to defend against military, terrorist, or criminal attack and to give warning of accidental or natural disasters. Chemists and chemical engineers will need to make new discoveries in basic science and apply them to the creation of useful materials and devices. These activities will need to address the threats to both military personnel and the civilian population. The range of threats in turn will include military or terrorist attacks on a massive scale, other assaults against just a few individuals, natural disasters, industrial accidents, transportation-related mishaps, and accidents in the home. The goals, to which chemical scientists can contribute, begin with early detection and prevention of an attack or event— but if prevention is not possible, they extend to mitigation of the effects and subsequent remediation of damage.

Ever since World War II spurred the development of technological advances such as radar, synthetic antimalarials, and synthetic rubber, our nation’s strengths

in science and technology have enabled us to prevail in the battlefield and marketplace. The United States currently has a military equipped with materials, communication devices, and supplies that result from fundamental research in materials synthesis and processing, electronics development, and biomedical advances.

Nuclear weapons, frightening and dangerous as they may be, are nevertheless a significant component of our overall national defense. A major national effort at this point is to make sure that they are not used in a war, or allowed to spread into less responsible hands. Chemistry played a large role in the development of nuclear weapons, enabling the chemical and isotopic separations procedures by which weapons-grade fissile materials could be isolated from highly complex mixtures. It was a remarkable achievement, solving a very difficult problem. Now analytical chemistry is heavily involved in detecting evidence for nuclear test explosions, to try to prevent the proliferation of nuclear weapons.

The production of weapons-grade uranium or plutonium is both technically challenging and expensive. Consequently, the source of this threat has been limited primarily to industrialized countries. In contrast, both industrialized and less developed countries might turn to the production of chemical weapons or biological weapons using dangerous viruses or bacteria. These are forbidden by international agreement,² but agreements do not necessarily provide a strong defense. Consequently, the U.S. military has put considerable effort into developing protective clothing and procedures to protect troops against chemical and biological weapons. The protective materials, and detoxifying procedures and substances, are the products of modern chemistry and chemical engineering.

A major contribution from chemistry and chemical engineering has been the development of materials with important military applications. Chemists and chemical engineers, working with experts from areas such as electronics, materials science, and physics, have contributed to such developments as new explosives and propellants, reactive armor (a complex material with an explosive layer that can reduce the penetration of an incoming projectile), and stealth materials that reduce the detectability of aircraft by radar.

Our personal civilian security is greatly enhanced by many contributions from chemistry and chemical engineering, often through integrated R&D efforts with teams of scientists from many disciplines. Law enforcement employs forensic tools that rely heavily on chemical analysis, and emergency response teams use a variety of protective clothing and equipment that rely on modern materials chemistry and engineering. As mentioned above, individual security extends to chemical detection methods in the home.

New research is needed to equip our military for new types of combat in diverse environments, and against well-equipped opponents. Increasingly, combat may occur in difficult areas, such as jungles or cities. These new situations require that soldiers be independent agents who are able to carry their weapons, communications, and supplies. Chemical scientists need to develop lightweight strong materials that could replace the heavy metal armor in fighting vehicles; new ultratough composites are a likely choice. Other lightweight materials will be needed for surveillance vehicles and to equip rapid response forces. Military vehicles will need better batteries and fuel cells to provide portable energy sources (Chapter 10).

The materials for uniforms and equipment will need to provide protection from chemical and biological agents (and perhaps detect them as well), be lightweight, and provide climate control to maintain performance in extreme environments. New medicines—antivirals, antibiotics, and antifungals—will be needed to maintain the health of troops deployed in such locations. In urban areas, advanced materials are needed for robots that can enter buildings before soldiers.

Combat medicine poses special problems. Chemical science and technology can aid in the rapid detection and treatment of injuries from chemical and biological weapons and other new weapons such as lasers. We need to develop blood substitutes with a long shelf life, and improved biocompatible materials for dealing with wounds. For the Navy, there are special needs such as analytical systems that can sample the seawater to detect and identify other vessels. We need good ways to detect mines, both at sea and on land. Land mines present a continued threat to civilians after hostilities have ended, and chemical techniques are needed to detect these explosive devices.

Of course our national security also depends on deterring problems before they arise. We need to develop new analytical chemistry techniques that are capable of detecting the production of materials in violation of the chemical and biological weapons treaties. Related detection technologies are needed to detect chemical agents and warn personnel accordingly. The new instrumentation will need to be versatile, robust, and portable—with miniaturization using approaches such as microfluidics as a likely goal.

Biological warfare agents present a greatly increased threat because the original viruses or bacteria can multiply and infect additional people. Considerable concern has been expressed over the possibility that a terrorist group might obtain a sample of the smallpox virus. Until recently, it was believed that smallpox had

been eradicated, with the exception of samples at two specialized facilities (in the United States and Russia). Other biological agents also create concern. For example, bacillus anthracis (anthrax) has long been viewed as a potential weapon because it can be converted to hardy spores for delivery as a dry powder. The events of 2001 showed anthrax to be a dangerous organism, but it is not transmitted from one human to another. Consequently, the death toll from anthrax-containing letters was relatively low, although the societal and psychological impact was huge.

How can chemists and chemical engineers respond? To guard against biological attacks, it will be necessary to develop rapid and reliable methods of detection. As the events of 2001 demonstrated, it is not acceptable to culture a sample and wait days to learn if a particular biological agent is present; it must be identified prior to the onset of symptoms. And if the agent is found, we will need new therapies (antivirals, antibiotics) and reliable methods for decontaminating the site of attack. Protection of personnel will also require new vaccines and new approaches for delivering drugs and vaccines. The development of new drugs and vaccines will need to be carried out in full recognition that genetically modified pathogens could be used in an enemy attack. All of this will require concerted research by chemists and chemical engineers in collaboration with other scientists; these studies necessarily will be interdisciplinary.

Chemical warfare agents are extremely toxic and very fast acting. Chemical scientists must develop better understanding of their mechanisms of action, and use this information to devise possible remedies. At present, the logical response to the chemical threat is prevention of exposure. Consequently, sensors and other fast analytical techniques must be developed. Rapid and reliable methods of decontamination are needed in the event that a chemical agent is detected. One concept, the “lab on a chip,” involves producing complete analytical systems in a compact electronic form; such small devices could then be deployed by airdrop and allow remote inspection. Such miniaturized analytical systems also could be carried by individual soldiers—providing them with individualized real-time detection capability for chemical and biological agents.

The chemical industry is an important part of the U.S. economy. The manufacturing sites, and the chemicals they make, store, and transport, represent targets for terrorist attack—either by causing a release of toxic chemicals or by diversion of chemicals for other purposes. The industry needs to be sure that it has broad up-to-date information from analyses and risk assessments of chemical plant safety, of site security, and of chemical transport security. These analyses need to be coupled with detection capabilities for response, verification and tracking. Even with good plans in place, appropriate procedures are also essential for dealing with any attacks. Chemists and chemical engineers will be challenged to

develop new products and processes that make the chemical industry inherently more secure. Once again, mitigation and decontamination procedures require the attention of chemists and engineers.

Countries and groups that lack access to nuclear weapons may still have opportunities to obtain radioactive materials such as spent nuclear fuel. A bomb in which a conventional explosive charge causes dispersal of radioactive material is known as a “dirty bomb.” Such a device could result in psychological effects exceeding the physical damage it caused. Once again, new techniques are needed for detection (of both the explosive and radioactive material), and decontamination procedures would be essential if such a device were used.

Research by chemists and chemical engineers will be needed for the development of new analytical techniques to detect nuclear proliferation threats and treaty violations. This will require establishing the characteristic signatures of both production and testing of weapons. Detection of these signatures will depend on chemical spectroscopy techniques, and advances in remote sensing.

Within the context of the U.S. weapons programs, the ban on testing nuclear weapons requires that other methods be developed to ensure the safety and reliability of existing weapons. As part of the stockpile stewardship program, it will be necessary to understand—through laboratory experiments and via computer simulation and modeling—the long-term changes that could affect the performance of the weapons in the stockpile. These include chemical effects such as corrosion as well as the results of self-irradiation on both nuclear and nonnuclear components of the weapons. What are the aging processes and their consequences on various components—including high explosives, electronics, and mechanical—and how will this affect performance? Successful modeling will require fundamental understanding of materials over all length scales and of their chemical behavior under extremes of temperature and pressure.

Bombings have long been a central threat from terrorism, and several major bombing attacks have been carried out in the United States over the last decade. Two earlier reports from the National Research Council outlined a number of opportunities for technical contributions by chemical scientists.³ The recommen-

dations in those reports emphasized further research to develop new and improved detection techniques, but new voluntary and regulatory approaches to controlling explosives and their precursor chemicals were suggested if the level of threat increases.

One of many underlying problems leading to conflict is the difference in standard of living between industrialized and developing countries.⁴ Much of this difference could be mitigated by technology to improve energy, information infrastructure, medicine and public health infrastructure, food, water, shelter, clothing, and other absolute necessities for poorer nations. A task for chemistry and chemical engineering is to improve the means to feed and shelter the world, to extend to less-wealthy nations some fraction of the benefits we enjoy.

In most respects, the terrorist threats to civilian populations are parallel to the military threats from chemical and biological agents, radiological materials, and explosives. Detection—with all its challenges to the chemical sciences—remains the key. But the response must be quite different if an attack takes place on a civilian target. In such a case, we would not be looking at a specific concentration of troops under management of senior military officers—whose goal must be a sufficient survival level that will enable the battle to be continued and won. In a civilian situation, reduction of casualties must take first priority.

Important opportunities in the area of response are found in the early stages of emergency response. Emergency personnel need improved materials—including clothing, gas masks, and gloves—for personal protection. These will need to be lightweight and long-lasting, with significant improvements over the current generation of protection suits that are too heavy, too hot, and too cumbersome.

The time scale for chemical and biological attacks is quite different. Explosives and chemical warfare agents such as nerve gases kill in seconds or minutes, but even the existence of a biological attack might not be recognized for days or weeks. The first responders in a chemical or explosive attack will be alerted by damage and casualties, and they will need to enter the disaster zone. They will need the appropriate protective gear along with the detection equipment to tell them what threat or agent(s) they are facing. Moreover, they will need equipment and chemicals that will allow them to decontaminate the site by destroying or removing whatever harmful agents may be present. Finally, their analytical equip-

ment will need the sensitivity and accuracy to tell them when decontamination has progressed adequately so that the disaster zone can again be declared safe. All of the new equipment and instrumentation will require the work of chemists and chemical engineers.

Biological attacks will likely be recognized not from a summons to the site of attack but by the steady accumulation of unusual data collected by medical personnel at hospital emergency rooms. Only when the collated data are properly interpreted will the biological attack be recognized as such. But then it will be necessary to engage our medical and public health systems quickly. To be ready for such an event, chemists and chemical engineers will need to carry out extensive work in collaboration with others in the biomedical field. It will be necessary to develop new and better vaccines, antivirals, and antibiotics. Better, faster ways of making and delivering these materials will have to be developed so that they are available in time to save lives. If a biological attack should take place, improved detection methods for biological agents will be needed immediately. A rapid, accurate, and reliable method is needed for detecting and identifying infected individuals before clinical symptoms appear. Many biological warfare agents produce conditions that are curable only if treated prior to the appearance of clinical symptoms. Waiting for the symptoms of a lethal disease to appear will not be an acceptable alternative. Chemists and chemical engineers will need to develop sensors, instruments, and analytical procedures to identify pathogens rapidly and reliably—thereby enabling medical personnel to respond accordingly.

Protection of our food and water supplies against terrorist attack presents a major challenge, because the supply chain is so extensive and open. But it is a challenge that chemists and chemical engineers should accept. Moreover, the threats to food and water are not limited to terrorism—a variety of natural disasters could wreak havoc as well.

A compelling sense of urgency was felt throughout the United States after the terrorist attacks of September 2001. For chemists and chemical engineers, this has emerged as motivation to align their research directions in ways that can help deter terrorism and protect our country from attack. Chemistry and chemical engineering have major roles to play in furthering our defensive capabilities against both military opponents and terrorists.

All of the areas of research discussed in this chapter will require interdisciplinary collaborations among chemists, engineers, biologists, physicists, and materials scientists. This critical area of national need should be the catalyst for breaking down disciplinary barriers and promoting interaction among scientific and engineering communities.

Among the many areas of research that can contribute to our national security, several stand out from the rest as central to the chemical sciences—materi-

als, medicines, and sensors. Advanced materials will play a crucial role in military and civilian protection, and advanced research in structured and functional materials on a nanoscopic scale will be an important focus for chemists and chemical engineers. The very real threat of virulent biological agents will drive chemists, biochemists, and chemical engineers to seek new prophylactic treatments, therapies, and protective vaccines. The need to protect millions of civilians in our own communities against acts of catastrophic terrorism must be a central priority for those working with analytical sensors and detectors, and for those working with genomics and analysis of pathogenesis. There cannot be many more important goals.