The pathology of lethal exposure to the Riot Control Agents: towards a forensics-based methodology for determining misuse.

The aim of this is to review deaths associated with the use of Riot Control Agents (RCAs) and to assess how the presenting pathologies is such cases may better inform cause of death conclusions upon autopsy. We also sought to present which additional steps should be added to the Minnesota protocol and the European harmonization of medico-legal autopsy rules in suspected cases of deaths associated with the use of RCAs. We included 10 lethal cases in our study. In three cases, RCAs were found to be the sole cause of death, in three cases RCAs were ruled a secondary cause of death due asphyxia or asthma subsequent to exposure to RCAs and in four cases RCAs were contributory factors to death. In three cases the responsible agents were identified as Chloroacetophenone (CN), Chlorobenzylidene malononitrile (CS) and Oleoresin capsicum (OC) and in the remaining 7 cases, the agent was OC alone. As there are no specific findings in suspected cases of death associated with RCA use, establishing cause of death and whether RCAs are the sole cause or only a contributory factor will be based on the elimination of other possible causes of death. For this reason, a specifically structured autopsy is essential. This specifically structured autopsy should contain basic principles of the Minnesota Protocol and the European harmonization of medico-legal autopsy rules with the following additional steps taken: examination of clothing, eyes, and skin; examination of pharyngeal, tracheobronchial, and eusophegeal mucosas; and a thorough recording of the steps taken by the party conducting the arrest, including other possible causes of in-custody death, as well as a detailed medical history of the deceased.

The syndrome of excited delirium.

The excited delirium syndrome (EDS) is a life-threatening condition caused by a variety of factors including drug intoxication and psychiatric illness. Fatal instances of excited delirium frequently come to the attention of the medical examiner/coroner due to the circumstances and potential causes. Excited delirium may include paranoid, aggressive, and incoherent behavior which may lead to an encounter with law enforcement. In some instances, the person may die while in the presence of law enforcement. This circumstance further broadens the potential causes of death particularly as EDS has no pathognomonic autopsy finding. Although the syndrome of excited delirium is sufficient to explain death, other intervening causes need to be considered. These include chest or neck compression during restraint, blunt trauma, and underlying natural disease. Since chest/neck compression, natural disease (e.g., atherosclerosis), blunt trauma, and excited delirium are not mutually exclusive, all may be present in one death. The forensic pathologist's role is to determine what caused and/or contributed to the death. When attempting to determine the proximate cause of death in instances with multiple potential causes, determining the mechanism of death often is useful. As not all causes of death have pathologically-demonstrable mechanisms of death, examination of the circumstances of the death often are diagnostically important. The main goal of the autopsy of deaths suspected to be due to EDS is to identify (or exclude) intervening diseases or injuries sufficient to explain the death in the context of the investigated circumstances.

Occupational contact dermatitis due to 2-chloracetophenone tear gas.

2-Chloracetophenone (CN) is widely used as tear gas by police and civilians for self-defence. It may affect the eyes, respiratory system and skin, sometimes causing serious injuries. Both irritative and allergic contact dermatitis have been described. We report three police officers who experienced accidental escape of CN from their professional tear gas canisters. All of them showed localized dermatitis at the site of contact to CN, while widespread lesions appeared after 4 days in one case. Patch tests with the original involved tear gas dissolved in acetone (at 0.1-0.0001%) indicated an allergic reaction in two patients and an irritative reaction in the third. Occupational contact dermatitis due to CN seems to occur among police officers more often than is generally known. Infrequently, extensive health problems may be caused by CN when lesions spread over the integument. Therefore, an improvement of safety measures in occupational CN gas use is needed, especially aiming at avoidance of accidental leakage of canisters.

Former poison gas workers and cancer: incidence and inhibition of tumor formation by treatment with biological response modifier N-CWS.

Mustard gas is known to have mutagenic and carcinogenic effects on animal and human cells. In this report, 1,632 male Japanese who worked in poison gas factories at some time between the years 1927 and 1945 were studied to determine comparative risk for development of cancer, the reference population being data on Japanese males overall. The standardized mortality ratio (SMR) for lung cancer in workers directly and indirectly involved in the production of mustard gas was significantly elevated. In addition, SMR for lung cancer in worker who had worked for more than 5 years was also significantly elevated. Thus, poison gas workers who had engaged in the production of mustard gas or related work for more than 5 years are a high-risk group for lung cancer. Under the cancer preventive program, Nocardia rubra cell-wall skeleton (N-CWS) was administered to 146 former poison gas workers. During a 4.5 year observation period, development of cancers was found in 7 treated workers and 17 untreated controls. After elimination of the influence of smoking level, a significant suppression of development of cancers was noted in the N-CWS-treated workers as compared to the untreated controls. Although the molecular mechanisms of carcinogenesis in former poison gas workers remains unclear, our study proposes the possible effect of biological response modifiers in the prevention of cancer development in high-risk human subjects.

Personal aerosol protection devices: caring for victims of exposure.

The increased incidence of violence in our society has led to a concern for personal safety. For self-protection, many individuals are turning to personal aerosol protection devices (PAPDs), which are readily accessible to the general public. The greater use and misuse of these noxious chemicals has led to an increase in injuries associated with exposure. Health care providers need to be aware of the modes of action of PAPDs, the presenting exposure symptoms, first aid measures, and decontamination procedures of the environment and the victim's belongings. This article provides a thorough discussion of PAPDs and will assist the clinician in delivering primary care and health education to victims of PAPD exposures.

[Lymphocyte stimulation test, a possible alternative for verifying chloroacetophenone sensitization]. / Lymphozytenstimulationstest, eine mögliche Alternative zur Sicherung einer Chloracetophenon-Sensibilisierung.

We report on a case of pronounced sensitization to chloroacetophenone tear gas that developed after repeated occupational skin exposure in a 57-year-old police officer. Mainly in the presence of moisture and occlusion, cutaneous application of chloroacetophenone leads to severe irritant, and often also allergic, skin reactions. In patch testing the demonstration of allergic contact dermatitis in response to chloroacetophenone is hampered by the irritative potential of this substance even at low concentrations. This diagnostic bias can be overcome by the lymphocyte proliferation assay.

Altered host resistance to Listeria monocytogenes in mice exposed to 1-chloroacetophenone (CN) vapours.

Short term repeated exposure of 1-chloroacetophenone (CN) vapours at a concentration of 0.153 mg per litre for 15 minutes daily on 10 consecutive days in Swiss albino male mice resulted in increased mortality to Listeria monocytogenes. Significantly elevated bacterial growth was observed in the spleen and liver of the CN exposed animals. The increased bacterial count in these organs was evident within 4-6 days post challenge as compared to vehicle exposed infected and unexposed infected animals. Increased susceptibility to infection has been considered to be the function of immune alteration due to cumulative short term effects of CN vapour inhalation. This may be attributed to immunotoxic effects of CN on T-cells mediated macrophage functions.

[Contact allergies to CN and CS ("tear gas") in participants in demonstrations]. / Zur Frage der Kontaktallergien auf CN and CS ("Tränengas") bei Demonstrationsteilnehmern.

56 occasional demonstrators were interviewed with regard to former skin contact with omega-chloroacetophenone (CN) or ortho-chlorobenzylidene malononitrile (CS). 33 persons (59%) reported skin reactions of various kinds. Patch testing with CN, the structurally related preservative chloroacetamide, and CS revealed clinically relevant reactions to CN in 3 cases and questionable positive reaction to CS in one case. 8 further patients showed mild reactions to CN and CS. We did not find any indication of cross reactions between CN and chloroacetamide.

Tear gas--harassing agent or toxic chemical weapon?

Tear gas has gained widespread acceptance as a means of controlling civilian crowds and subduing barricaded criminals. The most widely used forms of tear gas have been o-chlorobenzylidenemalononitrile and omega-chloroacetophenone. Proponents of their use claim that, if used correctly, the noxious effects of exposure are transient and of no long-term consequences. The use of tear gas in recent situations of civil unrest, however, demonstrates that exposure to the weapon is difficult to control and indiscriminate, and the weapon is often not used correctly. Severe traumatic injury from exploding tear gas bombs as well as lethal toxic injury have been documented. Moreover, available toxicological data are deficient as to the potential of tear gas agents to cause long-term pulmonary, carcinogenic, and reproductive effects. Published and recent unpublished in vitro tests have shown o-chlorobenzylidenemalononitrile to be both clastogenic and mutagenic. Sadly, the nature of its use renders analytic epidemiologic investigation of exposed persons difficult. In 1969, eighty countries voted to include tear gas agents among chemical weapons banned under the Geneva Protocol. There is an ongoing need for investigation into the full toxicological potential of tear gas chemicals and renewed debate on whether their use can be condoned under any circumstances.

[Contact dermatitis caused by 2-chloroacetophenone following tear gas exposure]. / Kontaktdermatitis auf 2-Chloracetophenon nach Tränengasexposition.

We report a case of acute contact dermatitis caused by exposure to 2-chloracetophenone tear gas in the face. Within 3 days the contact dermatitis had disappeared without medical treatment, but 7 days after exposure, a scaly pruritic eruption developed at the site of the original exposure although no new contact with 2-chloracetophenone had taken place.

[Contact allergy to CN and CS tear gas]. / Kontaktallergie auf CN- und CS-Tränengas.

Tear gases are used as riot control agents on account of their irritant properties. Five cases of allergic contact dermatitis due to omega-chloroacetophenone (CN) and one case additionally due to 2-chlorobenzylidene-malonitrile (CS) are reported.