Firecracker Powder: A Unique Source of Burn Injuries.

Firecrackers are a common cause of burns in India; large-scale use of firecrackers is seen during the festival of Diwali, and patients of all age groups present with varying patterns of firecracker burns. With the recent ban of firecrackers in some parts of the country, we have noticed a new emerging cause of burns during Diwali where patients were attempting to prepare firecrackers at home using Gandhak (sulfur) and potash by mixing the materials in a pipe gun. Explosion of this powder leads to varying degree of burns, and this series reports 12 such cases who presented to a tertiary care burn unit in North India during the 2022 festival of Diwali.

Chemical Analysis of Gunpowder and Gunshot Residues.

The identification of firearms is of paramount importance for investigating crimes involving firearms, as it establishes the link between a particular firearm and firearm-related elements found at a crime scene, such as projectiles and cartridge cases. This identification relies on the visual comparison of such elements against reference samples from suspect firearms or those existing in databases. Whenever this approach is not possible, the chemical analysis of the gunpowder and gunshot residue can provide additional information that may assist in establishing a link between samples retrieved at a crime scene and those from a suspect or in the identification of the corresponding model and manufacturer of the ammunition used. The most commonly used method for the chemical analysis of gunshot residue is scanning electron microscopy with energy dispersive X-ray, which focuses on the inorganic elements present in ammunition formulation, particularly heavy metals. However, a change in the legal paradigm is pushing changes in these formulations to remove heavy metals due to their potential for environmental contamination and the health hazards they represent. For this reason, the importance of the analysis of organic compounds is leading to the adoption of a different set of analytical methodologies, mostly based on spectroscopy and chromatography. This manuscript reviews the constitution of primer and gunpowder formulations and the analytical methods currently used for detecting, characterising, and identifying their compounds. In addition, this contribution also explores how the information provided by these methodologies can be used in ammunition identification and how it is driving the development of novel applications within forensic ballistics.

Computer Vision in Analyzing the Propagation of a Gas-Gunpowder Jet.

A method of mathematically processing the digital images of targets is developed. The theoretical and mathematical justification and the experimental validation of the possibility of estimating the amount of gunshot residue (GSR) and determining the GSR distribution over the target on the basis of its digital image is provided. The analysis of the optical density in selected concentric rings in the images reveals the radial dependence of soot distribution in the cross section of a gas-gunpowder jet. The analysis of the optical density in selected sectors of the circle reveals the angular dependence of the soot distribution in the gas-gunpowder jet cross section. It is shown that the integral optical density averaged over a selected area in the target image characterizes the mass of GSP deposited on it. It is possible to quantify the differences in the radial and angular distributions of the thickness of the GSR layer on various targets obtained both with the help of weapons of different types at the same distances and with the help of weapons of the same type at different distances, by calculating the distribution of optical density on their digital images.

Examination of firearm gunpowders by scanning electron microscopy/energy dispersive X-ray analysis.

The surfaces of thirty-one gunpowders (GPs) from Winchester, Federal, Hercules, DuPont, and Remington were examined by scanning electron microscopy/energy dispersive X-ray spectroscopy. Particles and surface coatings on 22 of the GPs had compositions of sulfur/potassium/barium or sulfur/potassium detected. Primer-like particles composed of lead/antimony/barium were found on surfaces of twelve GPs. Gunpowders from fifteen different lots of Winchester 9 mm Silvertip® hollow point cartridges were found to vary in GP type (flake and flattened ball) and associated inorganic compounds of sulfur/potassium/barium or sulfur/potassium or one with only potassium. No inorganic particles or coatings were detected on two of these Winchester GPs. The elements from the inorganic compounds on GPs likely contribute to gunshot residue generated by the discharge of a firearm.

Oxygen Was Almost Named Nitrogen.

In his Tractatus Quinque Medico-Physici of 1674, John Mayow wrote that a fifth of atmospheric air is comprised of nitro-aerial spirit. That so-called spirit participates in both respiration and combustion. The etymology of "nitro-aerial spirit" stems from a mineral long called niter and now specified as potassium nitrate. Niter mixed with sulfur and carbon is gunpowder, developed in the ninth century in China. Mayow appreciated that niter was the oxidant in the energy-yielding reaction of gunpowder. The word "oxygen," eventually prompting the word oxidant, was coined a century later by Antoine Lavoisier.

Dual isotopic (δ15N-δ18O) characterization of saltpetre currently prevailing in Lao PDR and its global compilation: new insight into isotope fractionation during production processes.

Saltpetre (KNO3; potassium nitrate) is one of the major ingredients of gunpowder. Simplex saltpetre (total 126 samples) together with gunpowder (total 93 samples) commodities which are currently prevailing in local markets as used for wildlife hunting and rocket festivals (local name in Lao: Boun Ban Fai) were collected from throughout Lao PDR. Dual isotopic composition of nitrates (δ15N, δ18O) was analyzed by the microbial denitrification method. Binary plotting of the data was conducted to characterize the mode of formation. In Lao PDR, almost all the commodities were imported from neighbouring Thailand, and to a lesser extent from Israel. Binary plotting of δ15N vs. δ18O of nitrates shows their intrinsic origin manufactured by Haber-Bosch and subsequently Ostwald processes. We observed an inverse correlation (δ15Nnitrate: up to + 12 ‰; δ18Onitrate: down to + 15 ‰), deviating from the reservoir values (free air) of δ15N (dinitrogen; up to 0 ‰) and δ18O (oxygen; +23.5 ‰), interpreted this as an indication of isotope fractionation during manufacture. The most plausible interpretation for this is the fractionation associated with formation of NO following NO2 and finally NO3 products. A nearly comparable inverse relationship is also observed for nitrates in pyrotechnics manufactured in China.

Dual (oxygen and nitrogen) isotopic characterization of the museum archived nitrates from the United States of America, South Africa and Australia.

Dual (oxygen and nitrogen) isotopic composition of the museum archived nitrates from the United States of America, South Africa and Australia was studied. The analyzed specimens were collected in middle 19th to early 20th centuries, and represent world-wide acquisition of the Smithsonian Institution Natural Museum of Natural History (Washington, D. C., USA) and the Natural History Museum (London, UK). The samples consist of transparent to semi-transparent aggregates of minute nitrate, euhedral crystallites which imply precipitation from percolating fluids under ample space and dry regimes. The major nitrate chemistry is saltpetre (KNO3) with minor nitratine (NaNO3). A binary plot of δ15N vs. δ18O of almost all nitrates indicates a trend, reflecting microbial origin through nitrification of ammonium. The diagram excludes the contribution of meteoric origin formed by mass-independent, photochemical reaction of NO with ozone in stratosphere. Calculated paleo-ambient fluid compositions responsible for microbial nitrification imply extreme evaporative concentration of relevant fluids under dry climatic regimes in the Northern Cape Province (South Africa) and in the Northern Territory (central Australia), and even throughout the United States of America. The dual isotopic characterization provides direct evidence to the origin of the museum archived nitrates.

A Study of the Presence of Gunshot Residue in Pittsburgh Police Stations using SEM/EDS and LC-MS/MS.

Due to possible secondary transfer of gunshot residue (GSR) onto a suspect in police custody prior to sampling, a baseline must be created for the amount of GSR present. With an increase of "lead free" ammunition, testing for both gunpowder and primer GSR is relevant. Seventy samples were collected using carbon-coated adhesive stubs from four Pittsburgh Police Stations and vehicles to investigate these locations as sources of secondary GSR contamination. These seventy samples were analyzed for primer GSR using scanning electron microscopy-energy-dispersive X-ray spectrometry. One primer GSR particle was detected; no sample was classified as positive for primer GSR. These same samples were then analyzed for gunpowder GSR using liquid chromatography coupled to tandem mass spectrometry to test for akardite II, ethylcentralite, diphenylamine, N-nitrosodiphenylamine, 2-nitrodiphenylamine, and 4-nitrodiphenylamine. Ethylcentralite was quantifiable in two test samples. These results suggest there is a negligible potential for secondary transfer of primer and gunpowder GSR.

Surface-enhanced Raman spectroscopy for the analysis of smokeless gunpowders and macroscopic gunshot residues.

Gunshot residues (GSR) result from the discharge of a firearm being a potential piece of evidence in criminal investigations. The macroscopic GSR particles are basically formed by burned and non-burned gunpowder. Motivated by the demand of trace analysis of these samples, in this paper, the use of surface-enhanced Raman scattering (SERS) was evaluated for the analysis of gunpowders and macroscopic GSR particles. Twenty-one different smokeless gunpowders were extracted with ethanol. SERS spectra were obtained from the diluted extracts using gold nanoaggregates and an excitation wavelength of 633 nm. They show mainly bands that could be assigned to the stabilizers diphenylamine and ethylcentralite present in the gunpowders. Then, macroscopic GSR particles obtained after firing two different ammunition cartridges on clothing were also measured using the same procedure. SERS allowed the detection of the particles collected with an aluminum stub from cloth targets without interferences from the adhesive carbon. The results demonstrate the great potential of SERS for the analysis of macroscopic GSR particles. Furthermore, they indicate that the grain-to-grain inhomogeneity of the gunpowders needs to be considered. Graphical Abstract SERS allows the detection of GSR particles collected with adhesive stubs from cloth targets using gold nanoaggregates and an excitation wavelength of 633 nm.

Puerarin attenuates smoke inhalation injury by regulation of Th1/Th2 expression and inhibition of Th17 cells in rats.

OBJECTIVE: Puerarin, a kind of traditional Chinese medicine, possesses immunomodulatory property. However, the immunomodulatory effects of puerarin on smoke inhalation injury have not been determined. The aim of the current study was to investigate the therapeutic efficacy of puerarin on gunpowder smog-induced acute lung injury in rats via regulation of Th1/Th2/Th17 expression. MATERIALS AND METHODS: Wistar rats were equally randomized to four groups (normal control group, puerarin control group, smoke inhalation injury group, puerarin treatment plus smoke inhalation injury group). The severity of lung injury was evaluated by histopathology, myeloperoxidase (MPO) activity in lung homogenates, cell counting in bronchoalveolar lavage fluid (BALF), and lung vascular permeability parameters including lung wet to dry weight ratio and protein concentration in BALF. Flow cytometry was used to analyze the expression of Th1/Th2/Th17 lymphocytes in blood of rats. RESULTS: Puerarin showed significant therapeutic effects against neutrophil infiltration and tissue injury, as evidenced by histopathological findings and MPO activity. Lung vascular permeability was also relieved by puerarin administration. Additionally, puerarin significantly decreased the number of neutrophils and lymphocytes in BALF compared with smoke inhalation injury group. Furthermore, puerarin increased Th1 immunity and reduced Th2 and Th17 responses and thereby altering the Th1/Th2/Th17 imbalance induced by smoke inhalation. CONCLUSIONS: Our findings suggested that puerarin suppressed inflammatory responses in gunpowder smog-induced acute lung injury by regulation of Th1/Th2/Th17 expression, and may be a potential therapeutic agent for smoke inhalation injury.

Protective effects of edaravone combined puerarin on inhalation lung injury induced by black gunpowder smog.

OBJECTIVE: The present study aimed to investigate the combined effects of puerarin with edaravone on inhalation lung injury induced by black gunpowder smog. MATERIALS AND METHODS: Male Wistar rats were divided into five groups (control group, edaravone group, puerarin group, edaravone combined with puerarin group and inhalation group). The severity of pulmonary injuries was evaluated after inducing acute lung injury. Arterial blood gas, inflammatory cytokines, biochemical, parameters, cell counting, W/D weight ratio and histopathology were analyzed. Results in lung tissues, either edaravone or puerarin treatment alone showed significant protective effects against neutrophil infiltration and tissue injury, as demonstrated by myeloperoxidase activity and histopathological analysis (all p<0.05). In addition, combined treatment with both edaravone and puerarin demonstrated additive protective effects on smog-induced lung injury, compared with single treatment. CONCLUSIONS: Combination of edaravone and puerarin shows promise as a new treatment option for acute lung injury/acute respiratory distress syndrome patients.

A new method for the determination of the nitrogen content of nitrocellulose based on the molar ratio of nitrite-to-nitrate ions released after alkaline hydrolysis.

A new method was proposed to determine the nitrogen content of nitrocelluloses (NCs). It is based on the finding of a linear relationship between the nitrogen content and the molar ratio of nitrite-to-nitrate ions released after alkaline hydrolysis. Capillary electrophoresis was used to monitor the concentration of nitrite and nitrate ions. The influences of hydrolysis time and molar mass of NC on the molar ratio of nitrite-to-nitrate ions were investigated, and new insights into the understanding of the alkaline denitration mechanism of NCs, underlying this analytical strategy is provided. The method was then tested successfully with various explosive and non-explosive NC-containing samples such as various daily products and smokeless gunpowders. Inherently to its principle exploiting a concentration ratio, this method shows very good repeatability in the determination of nitrogen content in real samples with relative standard deviation (n = 3) inferior to 1.5%, and also provides very significant advantages with respect to sample extraction, analysis time (1h for alkaline hydrolysis, 3 min for electrophoretic separation), which was about 5 times shorter than for the classical Devarda's method, currently used in industry, and safety conditions (no need for preliminary drying NC samples, mild hydrolysis conditions with 1M sodium hydroxide for 1h at 60 °C).

[Acoustic trauma generated by exposure to gun powder]. / Trauma acústico generado por exposición a explosión de pólvora.

BACKGROUND: Noise-induced hearing loss has increased due to factors such as industrialization. It is estimated that one third of the world's population suffers from some degree of hearing loss caused by exposure to high-intensity noise. Exposure to noise can cause disease of various ear structures, especially destruction of outer hair cells, causing varying degrees of hearing lossObjective: To describe the audiological findings in a group of subjects who were exposed to a source of fireworks explosion in the state of Tlaxcala Mexico. METHODOLOGY: We carried out an audiometric study in eight patients admitted to CENIAQ-INR who were exposed to a firecracker explosion. In each subject, airway with conventional pure tone audiometry from 125 to 8000 Hz was assessed using a clinical audiometer (model 622, Minimate, Madsen) Clinical case: Hearing loss at all frequencies was found in all eight patients, from mild to severe in both ears. Audiogram showed decreases from 4000 Hz, diagnosing third-degree acoustic trauma in all patients. CONCLUSIONS: The main symptom was reported by patients with tinnitus. Other scenarios in which patients report the presence of tinnitus are acoustic trauma due to use of audio players in symphony orchestra musicians and detonating military firearms. Audiometric assessment is recommended after an explosive accident as an accurate method to determine if there is any hearing impairment.

Antecedentes: la pérdida auditiva inducida por ruido se ha incrementado debido a factores como la industrialización. Se estima que un tercio de la población mundial padece algún grado de hipoacusia causada por exposición a ruidos de alta intensidad. La exposición al ruido puede afectar diferentes estructuras del oído y destruir las células ciliadas externas, que provocan diferentes grados de hipoacusia. Objetivo: describir los hallazgos audiológicos encontrados en un grupo de personas expuestas a una fuente de explosión en el estado de Tlaxcala, México. Metodología: estudio transversal, descriptivo, con muestreo censal efectuado en ocho pacientes ingresados al Centro Nacional de Investigación y Atención de Quemados del Instituto Nacional de Rehabilitación, expuestos a una explosión de pólvora. En cada sujeto se evaluó la vía aérea con audiometría de tonos puros, convencional, de 125 a 8000 Hz. Se utilizó un audiómetro clínico marca Madson, modelo Midimate 622, de dos canales y audífonos THD 39. Casos clínicos: en los 8 pacientes se encontró hipoacusia en todas las frecuencias, de media a severa en ambos oídos. Las audiometrías tuvieron caídas a partir de los 4000 Hz, en todos los pacientes se diagnosticó trauma acústico de tercer grado. Conclusiones: el principal síntoma referido por los pacientes fue el acúfeno, otros estudios donde los pacientes refieren acúfeno son, en el trauma acústico por uso de reproductores de audio, en músicos de orquesta sinfónica y en militares por detonación de arma de fuego. Para determinar de manera certera si existe alguna disfunción auditiva posterior a un accidente explosivo se recomienda la valoración audiométrica.

Determination of the nitrogen content of nitrocellulose by capillary electrophoresis after alkaline denitration.

Nitrocellulose (NC) is a nitrate cellulose ester polymer whose nitrogen content determines its physical and chemical properties and its industrial applications. For the first time, capillary electrophoresis (CE) was used to quantify nitrite and nitrate ions released after the alkaline hydrolysis of NC to determine its nitrogen content. This article focuses on the development and validation of the CE method adapted to the determination of these anions in basic matrices in 3 min total runtime. Molybdate anion was used as internal standard. The matrix effect in sodium hydroxide solution was statistically studied, demonstrating that no significant effect occurred in 0.5M sodium hydroxide solution. RSDs on normalized migration times (n=20) were 0.05% for both anions, while RSDs on normalized corrected areas (n=20) were 0.8% and 0.7% for nitrite and nitrate ions, respectively. The selectivity of the CE method was checked in the presence of 10 other anionic species potentially present in post-blast residues. Excellent linearities for normalized corrected areas (R(2)>0.999, residual standard deviations of ca 0.05) were obtained for both anions in the range 5-100 mg L(-1). Finally, the optimized CE method was successfully applied to calculate the denitration yields of two NC standards belonging to the non-explosive and explosive classes, and to determine the nitrogen content of a NC contained in a single-base gunpowder. CE, with its speed, low running costs, and simplicity of use, appears as a valuable alternative to ion chromatography for the nitrogen content determination of pure NCs and NC-based explosives, and more generally, for the determination of nitrite and nitrate ions in other highly alkaline matrices.

Detection of gunshot residue on dark-colored clothing prior to chemical analysis.

Detection of gunshot residue (GSR) is an arduous task for investigators. It is often accomplished with chemical tests, which can reveal elements and ions indicating the presence of GSR, but are likely to cause physical alteration to the pattern. In this study, the Spex Forensics Mini-CrimeScope MCS 400, along with 16 accompanying wavelength filters, was applied to various GSR patterns and target types. Three dark shirt materials, four ammunition calibers, and eight ammunition manufacturers, along with the primer residue of the different manufacturer ammunitions were tested. Results indicate the alternate light source wavelength of 445 nm to be the optimal setting. In addition, target material plays a large role in the preservation of GSR patterns as particles burn. Furthermore, it can be extrapolated that residue, observed from a full round and firing distance of six inches, is mostly composed of unburnt gunpowder residue, not primer residue.

Pico de fluxo expiratório em trabalhadores de fábricas de fogos de artifício / Expiratory peak flow in employees of firework factories

Objetivo. A pólvora é uma mistura explosiva constituída de 75% de salitre (nitrato de potássio), 12% de carvão e 13% de enxofre, moídos em conjunto. O objetivo deste trabalho foi verificar possível acometimento respiratório de trabalhadores de fábricas de fogos de artifícios por pólvora inalada. Método. Foram medidos os picos de fluxo expiratório de 234 pessoas do Município de Santo Antônio do Monte, Minas Gerais: 41 sem exposição profissional à pólvora (grupo-controle) e 193 trabalhadores de fábricas de fogos de artifícios. Os parâmetros utilizados foram: idade, sexo, estatura, peso, tabagismo e tempo de exposição à pólvora. Resultados. Todos os indivíduos pertencentes ao grupo-controle tiveram seus níveis de pico de fluxo expiratório dentro da normalidade. Em 50 (25,9%) trabalhadores, houve redução desse fluxo, 34 (68%) eram tabagistas, dez (20%) tinham de cinco a dez anos de exposição e dez (20%) tinham mais de dez anos de exposição. Conclusão. A pólvora relaciona-se com a redução de pico de fluxo expiratório, principalmente em indivíduos tabagistas.

Objective. Gunpowder is an explosive blend of potassium nitrate (75%), coal (12%) and sulphur (13%). The present investigation verified respiratory consequences of this powder in employees of firework factories. Method. The expiratory peak flow was assessed in 234 habitants of Santo Antônio do Monte, Minas Gerais State: 41 healthy volunteers (control group) and 193 employees of firework factories. The parameters assessed were age, sex, height, smoking and time of gunpowder exposition. Results. The level of the expiratory peak flow of the control group was normal. Reduction of the expiratory flow occurred in 50 (25.9%) of the factories workers: 34 (68%) of them were smokers and ten (20%) had more than tem years of exposition to gunpowder. Conclusion. Gunpowder is related with reduction of expiratory peak flow, mainly in smokers.