Riot control agents: the tear gases CN, CS and OC-a medical review

Using 2-(2-Chlorophenyl)thiazolidine-4-carboxylic Acid as a Novel Biomarker for 2-Chlorobenzalmalononitrile Exposure

This study addressed the development of a novel biomarker for 2-chlorobenzalmalononitrile (CS) gas exposure. Using liquid chromatographic and mass spectrometric techniques, we found that CS underwent rapid hydrolysis into 2-chlorobenzaldehyde (2-CBA), a highly reactive intermediate that reacted swiftly with endogenous cysteine (Cys) and Cys residues in proteins, producing a stable 2-(2-chlorophenyl)thiazolidine-4-carboxylic acid adduct (ClPh-SPro) in high yield, which may be used as a CS exposure dosimeter. In particular, it was found that most CS was rapidly hydrolyzed under physiologically relevant conditions, with over 90% of CS being converted into 2-CBA in as short as 20 min. The resultant 2-CBA then reacted swiftly with Cys (k = 0.086 M-1 s-1), forming the stable thiazolidine-4-carboxylic acid adduct, which was detected both in the intracellular fluid and in the cell-isolated proteins of CS-exposed lung cells, as well as in purified human serum albumin. It is expected that the results of this study will facilitate exposure assessment for bystanders who may have been exposed to high levels of CS gas unwillingly.

Catalytic activation of peracetic acid for pelargonic acid vanillylamide degradation by Co3O4 nanoparticles in-situ anchored carbon-coated MXene nanosheets: Performance and mechanism insight

Pelargonic acid vanillylamide (PAVA), a capsaicin-type dacryagogue agent utilized for counter-terrorism and riot control, possesses a low stimulus threshold. This characteristic can lead to environmental contamination following its application and may easily result in secondary stimulation to personnel. Cobalt-doped Ti3C2-MXene nanosheets (Co3O4/Ti3C2@C) were synthesized for the purpose of activating peracetic acid (PAA) and degrading PAVA. A carbon layer was coated on the surface of Ti3C2-MXene nanosheets to address the challenge of poor oxygen resistance in MXenes, thus preventing a significant decline in surface reactivity. The BET surface area of Co3O4/Ti3C2@C was expanded to 149.6 m2/g, significantly exceeding that of Ti3C2 (13.0 m2/g) and Co3O4 (56.4 m2/g). With 0.5 mg/mL of Co3O4/Ti3C2@C and 0.35 mM of PAA, 100 mg/L of PAVA was completely degraded within 60 min. The augmented BET surface area and the presence of more active sites confer remarkable PAA activation and catalytic degradation properties toward PAVA. Parameters such as initial pH, PAVA concentration, catalyst dosage, and PAA concentration on PAVA degradation were systematically assessed. Furthermore, the reusability and stability of the nanocomposite were substantiated through recycling tests. Radical quenching experiments and electron paramagnetic resonance analysis demonstrated the acetylperoxy radical (CH3CO3) as the primary species responsible for PAVA degradation. This research serves as an illustration of the utilization of MXene and transition metal activated PAA in wastewater treatment.

Pharmacologic Inhibition of Transient Receptor Potential Ion Channel Ankyrin 1 Counteracts 2-Chlorobenzalmalononitrile Tear Gas Agent-Induced Cutaneous Injuries

Deployment of the tear gas agent 2-chlorobenzalmalononitrile (CS) for riot control has significantly increased in recent years. The effects of CS have been believed to be transient and benign. However, CS induces severe pain, blepharospasm, lachrymation, airway obstruction, and skin blisters. Frequent injuries and hospitalizations have been reported after exposure. We have identified the sensory neuronal ion channel, transient receptor potential ankyrin 1 (TRPA1), as a key CS target resulting in acute irritation and pain and also as a mediator of neurogenic inflammation. Here, we examined the effects of pharmacologic TRPA1 inhibition on CS-induced cutaneous injury. We modeled CS-induced cutaneous injury by applying 10 μl CS agent [200 mM in dimethyl sulfoxide (DMSO)] to each side of the right ears of 8- to 9-week-old C57BL/6 male mice, whereas left ears were applied with solvent only (DMSO). The TRPA1 inhibitor HC-030031 or A-967079 was administered after CS exposure. CS exposure induced strong tissue swelling, plasma extravasation, and a dramatic increase in inflammatory cytokine levels in the mouse ear skin. We also showed that the effects of CS were not transient but caused persistent skin injuries. These injury parameters were reduced with TRPA1 inhibitor treatment. Further, we tested the pharmacologic activity of advanced TRPA1 antagonists in vitro. Our findings showed that TRPA1 is a crucial mediator of CS-induced nociception and tissue injury and that TRPA1 inhibitors are effective countermeasures that reduce key injury parameters when administered after exposure. Additional therapeutic efficacy studies with advanced TRPA1 antagonists and decontamination strategies are warranted. SIGNIFICANCE STATEMENT: 2-Chlorobenzalmalononitrile (CS) tear gas agent has been deployed as a crowd dispersion chemical agent in recent times. Exposure to CS tear gas agents has been believed to cause transient acute toxic effects that are minimal at most. Here we found that CS tear gas exposure causes both acute and persistent skin injuries and that treatment with transient receptor potential ion channel ankyrin 1 (TRPA1) antagonists ameliorated skin injuries.

Oleoresin Capsicum (OC) Spray: An Assessment of Respiratory Health and its Management Following Accidental and Deliberate Exposures

Introduced into law enforcement in 1976, the oleoresin capsicum (OC) spray has been labeled as one of the most significant and radical developments in law enforcement. However, epidemiological research on OC health effects is deficient, receiving little public support. The major responses to acute exposure to OC spray can be found in the pulmonary system. The molecular mechanism(s) involved in the action of capsaicinoids, the active constituents in OC, are complex cascades of reactions which end up in necrosis or apoptosis. OC may also damage and deplete biological redox systems in the epithelial lining fluids and within cells and mitochondria, modifying structural proteins and nucleic acids and leading to enzyme inactivation. Since there are no characteristic laboratory tests available for identification or confirmation of OC exposure, and on the basis of prevailing data, reassessment of the health risks of OC exposures in vulnerable populations and in-depth study of the molecular mechanics of receptors is the need of the hour for the development of effective countermeasures. This review aims to consider evidence for adverse effects of OC spray used in ways comparable to their application by law enforcement personnel and civilians, with possible treatment recommendations that are precedent for improved management.

Investigating the effects of dermal exposure to in-vivo animal models on the riot-control properties of a powder formulation of Tragia involucrata leaf hair lining

Purpose: Riot control agents (RCAs) such as CS, CN, CR, PAVA, and OC, etc., are already in use and has produced numerous health risks, including skin burns, dermatitis, gastrointestinal issues, impairment of respiratory variables, conjunctivitis, etc., and even prolonged and repeated exposure may cause death. Therefore, there is a demand and need for non-lethal, non-toxic RCAs that can effectively control riots without resulting in fatal outcomes. This study was carried out to evaluate the health risks related to a novel formulation made from isolated Tragia involucrata leaf hair lining, that can be used as the best suitable non-lethal RCAs.Methods: According to the OECD guidelines, studies on acute dermal toxicity, dermal irritation/corrosion, and skin sensitisation were carried out. Wistar rats were used in an acute dermal toxicity study, and the results indicated no mortality, morbidity, or abnormal food-and-water intake, biochemical parameters, or histopathological examination findings. A study on dermal irritation in Rabbits produced moderate erythema and the effect was instantaneous and resolved within 72 hrs of post-exposure. A skin sensitisation test was conducted on Guinea pig.Results: The results showed that the formulation had moderate skin-sensitizing properties after the application of the challenge dose. Patchy erythema was seen, and it went away 30 hrs after the gauze patch was removed.Conclusion: The preclinical results did not produce any indication of severe toxicity which supports it to be used as a natural RCAs in the future.

Monitoring trends in lacrimator exposures using the National Poison Data System: 2000-2021

CONTEXT

Lacrimators are used by individuals for personal defense and by police for crowd control during periods of civil unrest. Increased public awareness about their use has raised concerns about their application and safety.

OBJECTIVE

To characterize patterns of lacrimator exposures in the United States, we describe temporal trends of calls to poison centers by demographics, substances, medical outcomes, exposure sites, and scenarios.

METHODS

A retrospective data analysis was performed for all single-substance lacrimator exposures in the United States reported to the National Poison Data System between 2000 and 2021. Descriptive analyses were performed to examine demographic characteristics, geographic distribution, product types and medical outcomes associated with lacrimator exposures.

RESULTS

A total of 107,149 lacrimator exposure calls were identified. There was an overall decrease in calls per year, from 6,521 calls in 2000 to 2,520 in 2020, followed by an increase to 3,311 calls in 2021. A declining trend was observed independent of total poison center call volume. Oleoresin capsicum was the most commonly reported substance (81,990, 76.5%). Individuals ages 19 years and younger accounted for 62% of calls, but adults ages 20 and over were more likely to develop major clinical effects (odds ratio 3.03; 95% confidence interval 1.91-4.81; P < 0.0001). The most common exposure site was "own residence," followed by schools. School exposures accounted for 15.8% of exposures in children ages 6-12 years and 37.7% in adolescents. Among calls with documented scenarios, 19.7% involved unintentional exposures due to children accessing lacrimators.

CONCLUSION

Lacrimator exposure calls to United States poison centers decreased from 2000 to 2021. Most calls pertain to oleoresin capsicum and individuals ages 19 and younger. Improper storage allowing children to have access to these chemicals, is a common scenario. Public safety interventions such as education about safe storage and use of lacrimators, improved product design, or regulatory changes may prevent unintentional exposures.

Recent advances in fluorescent and colorimetric chemosensors for the detection of chemical warfare agents: a legacy of the 21st century

Chemical warfare agents (CWAs) are among the most prominent threats to the human population, our peace, and social stability. Therefore, their detection and quantification are of utmost importance to ensure the security and protection of mankind. In recent years, significant developments have been made in supramolecular chemistry, analytical chemistry, and molecular sensors, which have improved our capability to detect CWAs. Fluorescent and colorimetric chemosensors are attractive tools that allow the selective, sensitive, cheap, portable, and real-time analysis of the potential presence of CWAs, where suitable combinations of selective recognition and transduction can be integrated. In this review, we provide a detailed discussion on recently reported molecular sensors with a specific focus on the sensing of each class of CWAs such as nerve agents, blister agents, blood agents, and other toxicants. We will also discuss the current technology used by military forces, and these discussions will include the type of instrumentation and established protocols. Finally, we will conclude this review with our outlook on the limitations and challenges in the area and summarize the potential of promising avenues for this field.

Noxious effects of riot control agents on the ocular surface: Pathogenic mechanisms and management

Riot Control Agents (RCAs) are chemical compounds used by law enforcement agencies to quell violent demonstrations as an alternative to lethal force and as part of police/military training. They are also known as tear gases because of the hallmark ocular irritation and lacrimation they cause. The most common RCAs include oleoresin capsicum (contained in Mace and pepper spray), chlorobenzylidene malononitrile, dibenzoxazepine, and chloroacetophenone (previously the main content of Mace); some of which have been in use for decades. Their immediate incapacitating effects are mediated through polymodal afferent fibers innervating the corneal surface, inducing the release of peptides that cause neurogenic inflammation. Although previously thought to have only transient effects on exposed patients more severe complications such as corneal stromal opacities, corneal neovascularization, neurotrophic keratopathy, conjunctival necrosis, and pseudopterygium can occur. Concerningly, the lack of research and specific therapies restrict the current management to decontamination and symptom-tailored support. This manuscript will provide an overview of the toxic mechanisms of RCAs, their clinical manifestations, and current therapy after exposure to tear gases.

Simultaneous determination of trace level riot control agents in environmental water by solid-phase microextraction and gas chromatography coupled with a Flame Ionization Detector

In this paper, a direct immersion solid-phase microextraction procedure for the simultaneous analyses of four primary riot control agents: 2-Chloroacetophenone, o-chlorobenzylidene malonitrile, Dibenz (b, f)-1,4-Oxazepine, and oleoresin capsicum at μg·L^-1 concentration from environmental water was developed. Several parameters that influence the extraction effectiveness were investigated, including fiber type, extraction temperature, extraction time, starring rate, and salinity. Under the recommended conditions, the optimized method had reasonable linearity and accuracy. The average recovery of this method ranged from 84% to 108.1%. The limit of detection for all the analytes ranged from 0.2 to 3 μg·L^-1 and the limit of quantification ranged from 1 to 10 μg·L^-1 , respectively. A relative standard deviation from 3.0% to 4.3% can be achieved depending on the compounds. The procedure was applied to analyze all the four riot control agents simultaneously in several environmental samples. This article is protected by copyright. All rights reserved.

Assessment of toxicological consequences upon acute inhalation exposure to chemically improvised nonlethal riot control combinational formulation (NCF) containing oleoresin capsicum and skatole

Sensory irritation is an acute adverse effect leading to temporary disability posed by riot control agents in various deployable forms are utilized by defense personal in violent mob attacks but their irreversible toxic effects and risk assessment have been a matter of concern. These intimidating risks of available riot control agents have led to exploring the pulmonary toxicity profile of the oil in water emulsion formulation developed for vicious crowd controls containing an irritant oleoresin capsicum, a malodorant (skatole), and a commercial dye, followed by characterization using standard methods. Nonlethal riot control combinational formulation (NCF) has been aimed to be the best possible low-lethal alternative for riot control measures. In this study, 30 min of acute inhalation exposure of NCF was given to Wistar rats and various respiratory parameters like lung dynamics, bronchoalveolar lavage fluid (BALF) cytological assays, pro-inflammatory cytokines estimation, antioxidant activity, collagen accumulation, cytotoxicity, in vivo lung imaging, western blot, histology of lung tissue, etc. were investigated to validate its potentiality and rate of irritation reversibility as nonlethal agents. An exaggerated physiological change like sensory irritation, changes in lung functional variables, increased pro-inflammatory cytokines, etc. were noticed initially without airway obstruction as the expression of nociceptive TRPV1 protein did not alter the physiological regulation of protective proteins like Nrf2 and HO-1 and also no abnormality was found in lung tissue architecture. In conclusion, it can be stated that this formulation can be explored as a nonlethal riot control agent intending to generate discomfort but with early reversibility of sensory irritation and no recurrence of toxicity.

Reevaluating tear gas toxicity and safety

Tear gases, or chemical demonstration control agents (DCA), were originally created as weapons that could severely disable or kill enemy troops. Though banned in war, these chemicals are still used in domestic policing. Here we review the available scientific literature on tear gas, summarizing findings from animal and environmental studies as well describing data from new human studies. We find a lack of scientific evidence supporting the safety of tear gas, especially regarding its long-term impacts on human health and the environment. Many of the available studies were published decades ago, and do not parse data by variables such as chemical type and exposure time, nor do they account for the diversity of individuals who are exposed to tear gas in real-life situations. Due to the dearth of scientific research and the misinterpretation of some of the available studies, we conclude that a serious reevaluation of chemical DCA safety and more comprehensive exposure follow-up studies are necessary.

Health issues and healthcare utilization among adults who reported exposure to tear gas during 2020 Portland (OR) protests: a cross-sectional survey

Background

Repeated use of chemical irritants for crowd-control by local and federal law enforcement during sustained racial justice protests in the U.S. has raised concerns about potential adverse health effects. The objective of this study was to describe the health consequences of exposure to tear gas agents and associated healthcare utilization among adults reporting recent exposure to tear gas.

Methods

A cross-sectional, self-administered web-based survey of a convenience sample of 2257 adults reporting recent exposure to tear gas in Portland, Oregon (U.S.), administered between July 30, 2020-August 20, 2020. Descriptive analyses were conducted on socioeconomic characteristics, reported health issues, utilization of healthcare services, and frequency of reported exposure to tear gas. Associations between reported mental health issues, healthcare utilization and race and/or ethnic categories were assessed using a chi-square test. For tests of association, racial and/or ethnic categories were divided into White/Non-Hispanic only and all other racial/ethnic categories due to a small number of Black, American Indian or Alaska Native, Asian/Pacific Islander, Hispanic participants and participants with multiple race and/or ethnic background. Effect sizes for the differences were expressed as Cramer’s V, a metric that measures associations between nominal responses. The Cochran-Armitage trend test was used to assess the relationship between health issues and the number of reported days of exposure to tear gas (i.e., a proxy dose of exposure) grouped into 1 day, 2–4 days, and ≥ 5 days. Missing data (item non-response) were omitted from the analysis.

Results

Almost all respondents (2116; 93.8%) reported physical (2114; 93.7%) or psychological (1635; 72.4%) health issues experienced immediately after (2105; 93.3%) or days following (1944; 86.1%) the exposure. A slightly higher proportion experienced delayed head or gastrointestinal tract issues compared with immediate complaints. The majority (1233; 54.6%) reported receiving or planning to seek medical or mental care. We observed a positive exposure-response trend for all except mouth-related delayed issues (p < 0.01).

Conclusion

Persons who reported exposer to tear gas agents also reported physical and psychological health issues over a multiple-day period. Health issues reported increased with the frequency of reported exposure, indicating a potential dose-response; these health effects often led to healthcare utilization. This study provides evidence of potential unexpected harms of tear gas in civilians.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10859-w.

In vitro decontamination efficacy of the RSDL® (Reactive Skin Decontamination Lotion Kit) lotion component against riot control agents: Capsaicin, Mace™ (CN) and CS

The study examined the degradation of riot control agents (RCAs): 2-chloroacetophenone (CN), 2-chlorobenzalmalononitrile (CS), and capsaicin, using the Reactive Skin Decontamination Lotion Kit (RSDL®) lotion and evaluated the the direct liquid phase reactivity of the RSDL lotion component with each RCA. RSDL lotion was mixed with the selected RCAs at different molar ratios. Reactivity of the active ingredient potassium 2,3-butanedione monoximate (KBDO) with the RCA was observed for one hour. Samples of 10 μL were taken and quenched, analyzed for residual RCA using LC-MS. CN, was degraded at molar ratios of two and above in less than 2 min. At a molar ratio of 1:1 KBDO:CN, ∼90 % of CN was degraded within 2 min, the remaining 10 % residual CN was observed for one hour without any change. CS, degradation of more than 68 % of CS was achieved at 20:1 M ratio of KBDO:CS within 1 h of reaction time. For capsaicin, no degradation was observed regardless of the higher molar ratios of up to 20:1 and longer reaction times of up to one hour. This study provides evaluation of neutralizing action of the RSDL lotion without assessment of the physical removal component by the RSDL Kit.

Biological Properties, Bioactive Constituents, and Pharmacokinetics of Some Capsicum spp. and Capsaicinoids

Pepper originated from the Capsicum genus, which is recognized as one of the most predominant and globally distributed genera of the Solanaceae family. It is a diverse genus, consisting of more than 31 different species including five domesticated species, Capsicum baccatum, C. annuum, C. pubescen, C. frutescens, and C. chinense. Pepper is the most widely used spice in the world and is highly valued due to its pungency and unique flavor. Pepper is a good source of provitamin A; vitamins E and C; carotenoids; and phenolic compounds such as capsaicinoids, luteolin, and quercetin. All of these compounds are associated with their antioxidant as well as other biological activities. Interestingly, Capsicum fruits have been used as food additives in the treatment of toothache, parasitic infections, coughs, wound healing, sore throat, and rheumatism. Moreover, it possesses antimicrobial, antiseptic, anticancer, counterirritant, appetite stimulator, antioxidant, and immunomodulator activities. Capsaicin and Capsicum creams are accessible in numerous ways and have been utilized in HIV-linked neuropathy and intractable pain.

Innate inflammatory response to acute inhalation exposure of riot control agent oleoresin capsicum in female rats: An interplay between neutrophil mobilization and inflammatory markers

Aim: The use of oleoresin capsicum (OC) sprays, due to their irreversible health effects has now grown into a matter of heated debate. In the present study, the early phase pulmonary events involving chemotactic and inflammatory mediators after short-exposure duration to OC have been presented.Materials and methods: Female Wistar rats used in the evaluation of respiratory parameters at 1 h, 3 h, and 24 h post-exposure, were sacrificed for the evaluation of blood cell counts, BALF cytokine estimation, lung capillary leakage, study of oxidative stress and histopathology of the lungs.Results: Results confirmed a dose-dependent effect of OC exposure on serum clinical chemistry and hematological parameters. Subsequent upregulation of IL-l and TNF-α indicated lung's responses to acute oxidant-induced injury and inflammation after OC exposure. Significant alterations in the pulmonary levels of reactive oxygen intermediates were seen following the inhalation of OC. Infiltration of polymorphonuclear leukocytes, mostly neutrophils, into the site of infection was evident in the cytocentrifuged samples of BALF. Histological samples of rat lung sections revealed the recruitment of inflammatory cells in the airways and around blood vessels in the subepithelium of conducting airways.Conclusion: Results of the present study demonstrated that, exposure to OC spray may mitigate inflammatory response and development of acute lung injury in rats. However, it can be concluded that although OC spray causes pulmonary hazards in the aforementioned concentrations, it can be used as a non-lethal riot control agent in minimal concentration. Understanding the in-depth mechanism of action in the molecular and receptor level will help in developing effective antagonist against OC.

Fatal Penetrating Head Injuries Caused by Projectile Tear Gas Canisters

BACKGROUND

Since their advent in the 1920s, tear gas canisters (TGCs) have been frequently used in crowd control. Few reports have documented nonpenetrating injuries attributed directly to TGCs. In this study, we report a case series of fatal penetrating head injuries caused by TGCs.

METHODS

We conducted a retrospective chart review of all the patients who were admitted to the Neurosurgery Teaching Hospital in Baghdad, Iraq, since the start of the antigovernment protests (October 2019). All patients who suffered penetrating head trauma caused by TGCs were included in our study. We collected patient demographics, wound location, neurologic examination, computed tomography (CT) scan findings, surgical management, and clinical outcomes.

RESULTS

We found 10 cases of penetrating head trauma caused by TGCs. All victims were men, with a mean age of 16 years (range, 14-19 years). The mean Glasgow Coma Scale score was 7 (range, 3-10). The neurologic examination revealed unilateral hemiplegia/hemiparesis and pupillary abnormality in 40% (n = 4) and 50% (n = 5) of the patients, respectively. CT scans revealed an extensive pattern of brain damage. Surgical intervention was done in 80% of cases (n = 8), which included removal of the TGC, wound debridement, and hemostasis. The in-hospital mortality rate was 100% (N = 10), with all fatalities occurring within 1-3 days of admission.

CONCLUSIONS

TGCs have the potential to cause lethal penetrating head injuries, calling for a reevaluation of their safety and methods of use in terms of human health.

Latent turn-on fluorescent probe for the detection of toxic malononitrile in water and its practical applications

A latent turn-on fluorescent probe for the detection of malononitrile (NCCH₂CN), a precursor of hydrogen cyanide (HCN) in the mammalian tissue metabolism, is developed based on reaction-based fluorophore generation for the first time. Malononitrile is utilized within a wide spectrum of academic and industrial applications, and it is a key reagent to make o-chlorobenzylidene malononitrile (CS gas; tear gas), which is used for riot control. Due to its extensive use as well as potential health risks and the environmental pollution, malononitrile monitoring method has been required. In this paper, we discovered that our key sensing platform, 6-(dimethylamino)-3-hydroxy-2-naphthaldehyde (named Mal-P1), responds sensitively and selectively towards malononitrile. The Knoevenagel condensation induced benzo [g]coumarin formation of Mal-P1 with malononitrile showed significant fluorescence turn-on response. In addition, Mal-P1 showed the malononitrile sensing ability in environmental samples (real water, CS gas) and imaging ability in biological sample (HeLa cell line) using fluorescence microscopy with low cytotoxicity. The successful demonstrations will facilitate further applications in a variety of fields.

TRPA1 and issues relating to animal model selection for extrapolating toxicity data to humans

The transient receptor potential ankyrin 1 (TRPA1) ion channel is a sensor for irritant chemicals, has ancient lineage, and is distributed across animal species including humans, where it features in many organs. Its activation by a diverse panel of electrophilic molecules (TRPA1 agonists) through electrostatic binding and/or covalent attachment to the protein causes the sensation of pain. This article reviews the species differences between TRPA1 channels and their responses, to assess the suitability of different animals to model the effects of TRPA1-activating electrophiles in humans, referring to common TRPA1 activators (exogenous and endogenous) and possible mechanisms of action relating to their toxicology. It concludes that close matching of in vitro and in vivo models will help optimise the identification of relevant biochemical and physiological responses to benchmark the efficacy of potential therapeutic drugs, including TRPA1 antagonists, to counter the toxic effects of those electrophiles capable of harming humans. The analysis of the species issue provided should aid the development of medical treatments to counter poisoning by such chemicals.

Riots in Beirut: Description of the Impact of a New Type of Mass Casualty Event on the Emergency System in Lebanon

INTRODUCTION

In the summer of 2015, Beirut experienced a garbage crisis that led to rioting. Riot control measures resulted in multiple casualties. This study examines injury patterns of riot victims presenting to the emergency department of a tertiary care center in a developing country.

METHODS

A retrospective study was conducted in the emergency department of the American University of Beirut Medical Center between August 22 and August 30, 2015. Patients seen in the emergency department with riot injuries were included. Patient characteristics, injuries, and resources utilized in the emergency department were analyzed.

RESULTS

Ninety-five patients were identified. Most patients presented to the emergency department within a short time period. The mean age of the patients was 28.0 ± 8.7 years. Most (90.5%) of the patients were males and 92.6% were protestors. Emergency medical services were utilized by 41.0% of patients. Laceration was the most common presenting complaint (28.5%), and blunt trauma was the most common type of injury (50.5%). The head/face/neck was the most common injured body region (55.8%). Most patients did not require blood tests or procedures (91.6% and 61.0%, respectively), and 91.2% of patients were treated in the emergency department and discharged. One patient required intensive care unit admission and another was dead on arrival.

CONCLUSIONS

Most patients had mild injuries on presentation. The emergency department experienced a high influx of patients. Complications and deaths can occur from seemingly nonlethal weapons used during riots and warrant effective prehospital and hospital disaster planning.

Extensive Exposure to Tear Gases in Ankara

OBJECTIVES

The most common chemical substances used as mass control agents are chloroacetophenone, chlorobenzylidene malononitrile, and oleoresin capsicum. These agents not only have local and rapid effects but also have systemic and long-term effects. The aim of the present study was to discuss the patterns of tear gas exposure and to investigate its effects on respiratory functions.

MATERIALS AND METHODS

A face-to-face survey was conducted in 86 individuals who had been exposed to tear gas indoor and outdoor during the public protests in June 2013.

RESULTS

The most frequently reported respiratory complaints included cough, dyspnea, phlegm, and chest pain. Spirometry measurements including forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁) were also performed. Indoor exposers have lower mean % predicted FVC and FEV₁ values than outdoor exposers. All complaints and signs were more common in indoor exposure to tear gas than in outdoor exposure.

CONCLUSION

Safety of the chemicals used as mass control agents during protests is doubtful as these agents are associated with several health risks.

Effects of Riot Control Training on Systemic Microvascular Reactivity and Capillary Density

Introduction

The main aim of the present study is to evaluate the effects of strenuous exercise, related to special military training for riot control, on systemic microvascular endothelial function and skin capillary density.

Materials and Methods

Endothelium-dependent microvascular reactivity was evaluated in the forearm skin of healthy military trainees (age 23.4 ± 2.3 yr; n = 15) using laser speckle contrast imaging coupled with cutaneous acetylcholine (ACh) iontophoresis and post-occlusive reactive hyperemia (PORH). Functional capillary density was assessed using high-resolution, intra-vital color microscopy in the dorsum of the middle phalanx. Capillary recruitment (capillary reserve) was evaluated using PORH. Microcirculatory tests were performed before and after a 5-wk special military training for riot control.

Results

Microvascular endothelium-dependent vasodilatory responses were markedly and significantly reduced after training, compared with values obtained before training. The peak values of microvascular conductance obtained during iontophoresis of ACh or PORH before training (0.84 ± 0.22 and 0.94 ± 0.72 APU/mmHg, respectively) were markedly reduced after training (0.47 ± 0.11 and 0.71 ± 0.14 APU/mmHg; p < 0.0001 and p = 0.0037, respectively). Endothelium-dependent capillary recruitment was significantly reduced after training (before 101 ± 9 and after 95 ± 8 capillaries/mm2; p = 0.0007).

Conclusions

The present study showed that a 5-wk strenuous military training, performed in unfavorable climatic conditions, induces marked systemic microvascular dysfunction, mainly characterized by reduced endothelium-dependent microvascular vasodilation and blunted capillary recruitment.

Chemical warfare agents. Classes and targets

Synthetic toxic chemicals (toxicants) and biological poisons (toxins) have been developed as chemical warfare agents in the last century. At the time of their initial consideration as chemical weapon, only restricted knowledge existed about their mechanisms of action. There exist two different types of acute toxic action: nonspecific cytotoxic mechanisms with multiple chemo-biological interactions versus specific mechanisms that tend to have just a single or a few target biomolecules. TRPV1- and TRPA-receptors are often involved as chemosensors that induce neurogenic inflammation. The present work briefly surveys classes and toxicologically relevant features of chemical warfare agents and describes mechanisms of toxic action.

Health impacts of chemical irritants used for crowd control: a systematic review of the injuries and deaths caused by tear gas and pepper spray

Background

Chemical irritants used in crowd control, such as tear gases and pepper sprays, are generally considered to be safe and to cause only transient pain and lacrimation. However, there are numerous reports that use and misuse of these chemicals may cause serious injuries. We aimed to review documented injuries from chemical irritants to better understand the morbidity and mortality associated with these weapons.

Methods

We conducted a systematic review using PRISMA guidelines to identify injuries, permanent disabilities, and deaths from chemical irritants worldwide between January 1, 1990 and March 15, 2015. We reviewed injuries to different body systems, injury severity, and potential risk factors for injury severity. We also assessed region, context and quality of each included article.

Results

We identified 31 studies from 11 countries. These reported on 5131 people who suffered injuries, two of whom died and 58 of whom suffered permanent disabilities. Out of 9261 total injuries, 8.7% were severe and required professional medical management, while 17% were moderate and 74.3% were minor. Severe injuries occurred to all body systems, with the majority of injuries impacting the skin and eyes. Projectile munition trauma caused 231 projectile injuries, with 63 (27%) severe injuries, including major head injury and vision loss. Potentiating factors for more severe injury included environmental conditions, prolonged exposure time, and higher quantities of chemical agent in enclosed spaces.

Conclusions

Although chemical weapons may have a limited role in crowd control, our findings demonstrate that they have significant potential for misuse, leading to unnecessary morbidity and mortality. A nuanced understanding of the health impacts of chemical weapons and mitigating factors is imperative to avoiding indiscriminate use of chemical weapons and associated health consequences.

Tear gas: an epidemiological and mechanistic reassessment

Deployments of tear gas and pepper spray have rapidly increased worldwide. Large amounts of tear gas have been used in densely populated cities, including Cairo, Istanbul, Rio de Janeiro, Manama (Bahrain), and Hong Kong. In the United States, tear gas was used extensively during recent riots in Ferguson, Missouri. Whereas tear gas deployment systems have rapidly improved-with aerial drone systems tested and requested by law enforcement-epidemiological and mechanistic research have lagged behind and have received little attention. Case studies and recent epidemiological studies revealed that tear gas agents can cause lung, cutaneous, and ocular injuries, with individuals affected by chronic morbidities at high risk for complications. Mechanistic studies identified the ion channels TRPV1 and TRPA1 as targets of capsaicin in pepper spray, and of the tear gas agents chloroacetophenone, CS, and CR. TRPV1 and TRPA1 localize to pain-sensing peripheral sensory neurons and have been linked to acute and chronic pain, cough, asthma, lung injury, dermatitis, itch, and neurodegeneration. In animal models, transient receptor potential inhibitors show promising effects as potential countermeasures against tear gas injuries. On the basis of the available data, a reassessment of the health risks of tear gas exposures in the civilian population is advised, and development of new countermeasures is proposed.

Exposure to the riot control agent CS and potential health effects: a systematic review of the evidence

o-Chlorobenzylidene malononitrile (CS) is one of the most extensively used riot control agents. Our aim was to conduct a systematic review of the potential health effects related to CS exposure. We searched for papers in English between 1991 and 2014. Thirty five (35) studies (25 case reports, seven descriptive studies and three analytical studies) were included in the review. In the twenty five case reports/series 90 cases of exposure to CS and their clinical effects are presented. Their mean age was 25.7 years and 62.0% were males. In addition, 61% of the cases described dermal, 40% respiratory, 57% ocular clinical effects. Life threatening situations as well as long-term health effects were found and were related with exposure to confined/enclosed space. Descriptive and analytical studies have shown attack rates ranging from 12% to 40%. Subjects who were sprayed by the police more often needed special treatment and reported adverse health effects. Apart from transient clinical effects, CS could have lasting and serious effects on human health. Better surveillance of the subjects exposed to CS and completion of cohort studies among exposed populations will illuminate the spectrum of the health effects of exposure to CS.