Journal of Health Science, 57(4) 311–333 (2011) 311 — Review — Research and Development of On-site Decontamination System for Biological and Chemical Warfare Agents Yasuo Seto∗ Third Department of Forensic Science, National Research Institute of Police Science, 6–3–1 Kashiwanoha, Kashiwa, Chiba 277–0882, Japan (Received May 16, 2011) Biological and chemical warfare agents (BCWAs) are diverse in nature including synthetic low molecular weight chemical warfare agents (gaseous choking and blood agents), volatile nerve gases and blister agents, non- volatile vomit agents and lachrymators, biological toxins (polar lowmolecular weight toxins andproteinous toxins), and microorganisms (viruses, rickettsia, chlamydia and bacteria). In the consequence management against chemical and biological warfare terrorism, speedy decontamination of casualties, goods, items and equipments, buildings and field is required for the minimization of the terrorism damage. At present, washing casualties and contaminated ma- terials with large volumes of water is the basic way, and hypochlorite solution is mainly used to decompose BCWAs. However, it still remains unsolved how to dispose the waste water contaminated with BCWAs, and decontaminat- ing reagents have serious problems of high toxicity to human, despoiling nature to environment, long finishing time and non-durability. In addition, the present decontamination technologies are not effective, nonspecifically affecting the surrounding non-target materials. Therefore, it is the urgent matter to build up usable decontamination system surpassing the present system. The author introduces the joint project of research and development of the novel decontamination system against BCWAs, in the purpose of realizing non-dangerous, rapid, specific, effective and economical on-site decontamination. The project consists of establishment of the evaluation methods for de- contamination, and verification of the present technologies and utilization of bacterial organophosphorus hydrolase, development of specific adsorptive elimination technologies using molecular recognition devices, and development of deactivation technologies using photocatalysis. Key words —— decontamination, chemical warfare agent, biological warfare agent, adsorption, molecular- recognition, photocatalysis INTRODUCTION days were not evaluated adequate. After 11 Septem- ber Attacks, the governments have strengthening the In the terrorism cases of 1995 Japan sarin (GB) countermeasure against the mass weapon terrorism. gas attack1) and 2001 United States postal anthrax Within the preparedness for adequate counterterror- attack,2) chemical warfare agents (CWAs)3–5) and ism, the promotion of the corresponding research biological warfare agents (BWAs)6) were used as and development (R&D) of science and technol- mass destruction weapons, and defenseless citizen ogy should be definitely considered. Especially, de- were suffered (former case: 12 died and more than tection of biological and chemical warfare agents 5000 injured; later case: 5 died and ten and several (BCWAs), composed of hazardous material moni- injured), causing great shock against the terrorism toring, security check and infectious disease surveil- threat all over the world. Although the volumes of lance in crisis management stage; on-site detec- the agents used were not large, these agents were tion in consequence management stage; and labora- peculiar, and countermeasures performed in those tory analysis and diagnosis in incident management ∗ stage, is regarded as the most important, and R&D To whom correspondence should be addressed: Third Depart- of the detection technologies has been performed ment of Forensic Science, National Research Institute of Po- in leading industrialized nations. In review articles liceScience, 6–3–1 Kashiwanoha, Kashiwa, Chiba 277–0882, and books the author introduces on-site detection of Japan. Tel.: +81-4-7135-8001; Fax: +81-4-7133-9173; E-mail: 7, 8) 9, 10) [email protected] BCWAs and laboratory analysis of CWAs. C 2011 The Pharmaceutical Society of Japan 312 Vo l. 57 (2011) However, concerning decontamination, at present ric acid (HCl) by reaction with water, which leads the countermeasure has been only performed based to inflammation of mucous membranes, and chlo- on the experience, and R&D of the related tech- rinate biomolecules, which leads to loss of biolog- nologies is not done scientifically. Establishment of ical function. In the World War 1st,chlorine (CL) adequate decontamination system is requested from and phosgene (CG) were used. Chloropicrin (PS) is the frontlines of the counterterrorism, and it is ur- used as fumigant for agricultural usage. CG shows gent to perform R&D by the large-scale coordina- toxicity after incorporation into the lungs without tion system among company (responding to man- particular irritation, and produces HCl several hours ufacture), university (responding to seeds creation) latter, leading to pulmonary emphysema. In water and government (responding to need indication). they are hydrolyzed to loose volatility and reactiv- Previously, the author reported the brief review on ity. the decontamination of BCWAs.11, 12) In this review Nerve gases17) manifest strong toxicity with article, the characteristics of BCWAs, the concept disturbance of nerve impulse by inhibiting synap- of on-site decontamination, the present situation of tic cholinesterase (ChE) activity and accumulating decontamination technologies, and R&D of decon- acetylcholine.18) They are diverse including very tamination system performed by the author’s group volatile GB, volatile soman (GD) and nonvolatile are stated. VX. They resemble structurally with organophos- phorus pesticides. G-agents (code names used by North Atlantic Treaty Organization) such as GB, CHARACTERISTICS OF BCWAs13, 14) GD and tabun (GA) were newly synthesized in Ger- many during the World War 2nd.V-agents such CWAs3–5) are low molecular weight (MW) as VX were synthesized by the Great Britain and compounds, and according to the toxicity to hu- U.S.A. after the World War 2nd.Nowadays, they are man, they are divided into “nerve gas”, “blister still stockpiled as negative legacy of the Cold War, agent”, “choking agent”, “blood agent”, “vomit and the disarmament has proceeded internationally. agent” and “tear gas (lachrymator).” In physical Small quantity of nerve gases incorporated into properties, they are diverse, including gases in nor- the body can be detoxified with suicide binding to malpressure and temperature (choking agents and blood ChE,18) liver carboxylesterase19) and with hy- blood agents), volatile liquids (nerve gases and blis- drolysis by blood paraoxonase (POX).20, 21) Nerve ter agents) and nonvolatile liquids or solids (vomit gases are easily hydrolyzed by nucleophilic attack agents and lachrymators). Figure 1 shows chem- of hydroxyl anion to form nontoxic polar hydroly- ical structures of CWAs, and Table 1 shows their sis products (alkaylmethylphosphonic acid etc.) and toxicities and manifestation times. CWAs are also loose volatility and toxicity.22) For example, GB diverse in the standpoint of usage, from blood and is hydrolyzed to form isopropylmethylphosphonic choking agents with high public warfare usage to acid (IMPA). IMPA is further hydrolyzed to form nerve gases and blister agents with only military methylphosphonic acid (MPA) under acidic condi- usage. The latter groups are designated as “sched- tion (Fig. 2). uled compounds” in the Chemical Weapon Conven- Blister agents manifest toxicity by causing in- tion15) and the related domestic lows “Low on the flammation of contact surfaces such as skins, eyes prohibition of Chemical Weapons and the Regula- and respiratory tracts. They possess heteroatom(s) tion of specific Chemicals (enforced 1997/3/19).”16) and active chlorines. Mustard compounds (sulfur Blood agents manifest toxicity by inhibiting mustard23) and nitrogen mustard) are converted to oxygen consumption via blood hemoglobin. Hy- cyclic ethylene sulfonium (ammonium) as interme- drogen cyanide (AC) and cyanogens chloride (CK) diate by leaving one chlorine molecule, showing inhibit cytochrome oxidase activity in respiratory high reactivity of alkylating biomolecules such as chains. Arsine destroys red blood cells. Cyanide proteins and nucleic acids. By reacting with water, has high public warfare usage such as gold plat- they are converted to nontoxic hydrolysis products ing, and CK and arsine are used in industrial man- such as thiodiglycol and ethanolamines. Lewisite ufacturing. Choking agents manifest toxicity by in- 1(L1)24) possesses two arsenic chlorine bonding, juring respiratory system such as nose, throat and which leads to rapid hydrolysis in water to produce lung, and disturb breathing. They possess active 2-chlorovinylarsonic acid (CVAA) and HCl, man- chlorine molecule(s), produce irritating hydrochlo- ifesting inflammation. L1 and CVAA covalently No. 4 313 Fig. 1. Structures of BCWAs bind with thiols such as protein cysteine residues, and eyes, which cause sneeze, cough, vomit and resulting in loss of biological function. Mustard gas head ache. They possess one bonding between triva- (HD) was used in military from the late of the World lent arsenic and chlorine (or cyanide). They are not War 1st,and even now large quantity is stockpiled. highly toxic, compared to blister agents. They are TheFormer Japanese Military Forms manufactured hygroscopic, and in water converted to nonirritat- HD, used it in the China-Japanese War, and aban- ing hydrolysis