Pharmacists crucial in plan for terrorist chemical weapons

Chemical weapons act on their victims through a number of mechanisms. They include nerve agents, chemicals that cause blistering (vesicants), choking agents, incapacitating agents, riot control agents, blood agents, and toxic industrial chemicals. With their knowledge of chemistry, microbiology, pharmacology, toxicology, and therapeutics, pharmacists are a valuable asset to health care facilities and government agencies planning for the unthinkable – a terrorist attack with chemical weapons.

In his article, clinical pharmacist and forensic pharmacologist Peter D. Anderson details the clinical effects chemical weapons, and their treatment. Nerve agents work by blocking the actions of acetyl cholinesterase (the chemistry involved is similar to how many pesticides kill). These toxins include sarin, tabun, VX, cyclosarin, and soman. Vesicants like sulfur mustard and lewisite produce blisters and damage the upper airways. Choking agents, which cause fluid to build up in the lungs (pulmonary edema), include phosgene and chlorine gas.

Incapacitating agents are temporary and "non-lethal," and include fentanyl and adamsite. Mace and pepper spray are familiar riot control methods. Blood agents include cyanide, which works by blocking oxidative phosphorylation in the body. Toxic industrial chemicals such as formaldehyde, hydrofluoric acid, and ammonia also merit consideration as terrorist weapons.

"Potential chemical weapons are in no way limited to the traditional agents that we think of as chemical weapons," Anderson explains.

The good news is that there are potential antidotes to these chemical agents, which can save lives if they are used quickly and correctly. Pharmacists need to work in their hospitals to prepare emergency plans, and with the pharmacy and therapeutic committees to stock for a potential chemical accident or terrorist attack. In the US, for example, The Centers for Disease Control and Prevention (CDC) maintains a Strategic National Stockpile of pharmaceuticals, medical equipment and supplies that can be sent in an emergency to any US state within 12 hours.

The threat from chemical agents may appear to be a symptom of our modern society, but the idea has been around since antiquity. Solon of Athens is said to have used hellebore roots (a purgative) to contaminate the water supply in the Pleistrus River during the Siege of Cirrha as long ago as 590 BC. Modern chemical warfare during World War I included the release by German soldiers of 150 tons of chlorine gas near Ypres, Belgium, and phosgene and nitrogen mustard also played a role in the conflict. Choking agents, vesicants, blood agents, and nerve gas joined the range of chemical weapons available by World War II. Even though conflicting nations produced these in large quantities, no major chemical weapon events occurred during World War II.

The Chemical Weapons Convention was finalized in 1993, prohibiting development, production, stockpiling, and use of chemical weapons. The treaty also mandated weapons destruction. 130 countries signed the convention (excluding Iraq and North Korea).

Although the article is about chemical weapons, Anderson emphasizes that pharmacists can also be a resource for biological, radiological and nuclear attacks as well as natural disasters.

More information: Emergency Management of Chemical Weapons Injuries by Peter D. Anderson is published in the Journal of Pharmacy Practice. The article is free to access here: http://jpp.sagepub … ull.pdf+html

Provided by SAGE Publications

Nuclear detector: New materials hold promise for better detection of nuclear weapons

 Northwestern University scientists have developed new materials that can detect hard radiation, a very difficult thing to do. The method could lead to a handheld device for detecting nuclear weapons and materials, such as a "nuclear bomb in a suitcase" scenario.

"The terrorist attacks of 9/11 heightened interest in this area of security, but the problem remains a real challenge," said Mercouri G. Kanatzidis, who led the research. "We have designed promising semiconductor materials that, once optimized, could be a fast, effective and inexpensive method for detecting dangerous materials such as plutonium and uranium."

Kanatzidis is a Charles E. and Emma H. Morrison Professor of Chemistry in the Weinberg College of Arts and Sciences. He also holds a joint appointment at Argonne National Laboratory.

The Northwestern materials perform as well as materials that have emerged from five decades of research and development, Kanatzidis said.

To design an effective detector, Kanatzidis and his team turned to the heavy element part of the periodic table. The researchers developed a design concept to make new semiconductor materials of heavy elements in which most of the compound's electrons are bound up and not mobile. When gamma rays enter the compound, they excite the electrons, making them mobile and thus detectable. And, because every element has a particular spectrum, the signal identifies the detected material.

The method, called dimensional reduction, will be published in the Sept. 22 issue of the journal Advanced Materials.

In most materials, gamma rays emitted by nuclear materials would just pass right through, making them undetectable. But dense and heavy materials, such as mercury, thallium, selenium and cesium, absorb the gamma rays very well.

The problem the researchers faced was that the heavy elements have a lot of mobile electrons. This means when the gamma rays hit the material and excite electrons the change is not detectable.

"It's like having a bucket of water and adding one drop -- the change is negligible," Kanatzidis explained. "We needed a heavy element material without a lot of electrons. This doesn't exist naturally so we had to design a new material."

Kanatzidis and his colleagues designed their semiconductor materials to be crystalline in structure, which immobilized their electrons.

The materials they developed and successfully demonstrated as effective gamma ray detectors are cesium-mercury-sulfide and cesium-mercury-selenide. Both semiconductors operate at room temperature, and the process is scaleable.

"Our materials are very promising and competitive," Kanatzidis said. "With further development, they should outperform existing hard radiation detector materials. They also might be useful in biomedicine, such as diagnostic imaging."

The work was a Northwestern team effort, involving three professors and their research groups. Kanatzidis made the materials; Bruce W. Wessels, the Walter P. Murphy Professor of Materials Science and Engineering in the McCormick School of Engineering and Applied Science, measured and evaluated the materials; and Arthur J. Freeman, a Charles E. and Emma H. Morrison Professor of Physics and Astronomy in Weinberg, provided theoretical predictions of the materials' performance.

In addition to Kanatzidis, Wessels and Freeman, other authors include John Androulakis, Sebastian C. Peter, Hao Li, Christos D. Malliakas, John A. Peters, Zhifu Liu, Jung-Hwan Song and Hosub Jin.

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Story Source:

The above story is reprinted (with editorial adaptations ) from materials provided by Northwestern University, via EurekAlert!, a service of AAAS.

Journal Reference:

John Androulakis, Sebastian C. Peter, Hao Li, Christos D. Malliakas, John A. Peters, Zhifu Liu, Bruce W. Wessels, Jung-Hwan Song, Hosub Jin, Arthur J. Freeman, Mercouri G. Kanatzidis. Dimensional Reduction: A Design Tool for New Radiation Detection Materials. Advanced Materials, 2011; DOI: 10.1002/adma.201102450