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PubMed1999

A basic test method for the study of explosion treatment of waste chemicals from laboratories.

As a part of the research on the explosion treatment of waste chemicals from laboratories, a basic test method, which will provide the basis for our future research, was developed. First, the basic explosive, the scale of the explosion chamber and the assembly of the sample were decided. Then, measurement of detonation velocity was carried out, and the relationship between the quantity of explosive and the state of detonation propagation was obtained. A quantitative method for evaluating the decomposability of organic chemicals under explosion treatment was investigated. The results indicate that evaluating the explosion decomposability of organic chemicals from the gasification ratio could be used as a basic method provided that the excessive oxygen is approximately 62 mol% or higher. Finally, examinations of the possible effects of the quantity of explosive and conditions of atmosphere on the explosion decomposition of the model substance were conducted, and the basic test conditions regarding the quantity of explosive and condition of atmosphere were decided.

Explosions↗
PubMed2003

Pathologic features of suicidal deaths caused by explosives.

Suicidal explosions that lack a terrorist background are only rarely encountered in the field of forensic pathology. The investigation of explosion-related fatalities can be a substantial challenge in medicolegal casework. Determining whether the manner of death is suicide, homicide, or accident in such cases can present an especially difficult task to the forensic pathologist. This study considers the pathologic features of suicidal deaths caused by explosives without a terrorist background. The modus operandi of the decedents reflected familiarity and proficiency, or at least a degree of specialized knowledge, with the construction and use of explosive devices. All explosions were set off in confined spaces. The injury patterns consisted of a combination of primary blast injuries (e.g. decapitation, traumatic amputation of limbs, gross lacerations of the body surface, blast injuries of gas-containing and hollow organs), secondary blast injuries (e.g. splinter-induced penetrating trauma), tertiary blast injuries (e.g. abrasions and contusions), and burn injuries (mostly of the flash type). The previously described symmetric distribution pattern of injuries in suicidal explosions was apparent only to a certain degree in the present series. Our observation of superficially sharp-edged wound margins with bridging in the depths of the lesion in blast-induced lacerations of the skin should deserve further attention in forthcoming cases of explosion-related fatalities because this finding is a diagnostic possibility that may support the theory of an explosion-related fatality under special circumstances, e.g. when the body has been dumped away from the place of death. Because a terrorist attack may be initially suspected in each case of suicide involving explosives, the importance of a joint inquiry based on expertise from police investigators, bomb experts, and forensic pathologists is evident.

Adult↗
PubMed2001

Force developmental phase and reliability in explosive and voluntary grip exertions.

The purposes of this study were to clarify the reliability of two types of grip exertions, explosive grip exertion and voluntary grip exertion up to the maximal grip strength and to examine their force patterns using force-time parameters. Subjects were 100 healthy young male volunteers (age: 17.8+/-2.50 yr.) who had no upper limb injury. Grip strength was measured two times with voluntary grip and then two times with explosive grip. 11 parameters derived from the force-time curve were selected to measure the developmental phase of muscle contraction. The reliability of maximal grip strength in explosive and voluntary grip exertions was very high (intraclass correlation = .95, .93). The difference between two trials in explosive grip tended to be smaller than that for voluntary grip, and reliability of the exertion pattern was higher for explosive grip than voluntary grip. The times to reach 90% of the maximal grip strength and the maximal grip strength in explosive grip were shorter than those in voluntary grip. The other 8 force-time parameters had higher values in explosive grip than voluntary grip and higher reliabilities. The force-time parameters reflect the properties of explosive exertion. The results suggest the possibility that static explosive strength could be evaluated using these force-time parameters.

Adolescent↗
PubMed2003

Trends in explosive contamination.

This study sought to assign a rough order of magnitude for the amount of explosive residue likely to be available in real-world searches for clandestine explosives. A variety of explosives (TNT, TATP, HMX, AN, RDX, PETN) in various forms (powder, flake, detonating cord, plastic) were carefully weighed or cut into containers, and the amount of residue inadvertently remaining on the work area, hands, or containers was quantified. This was used to evaluate the spillage potential of each explosive. The adhesion of each explosive to a glass surface was quantified from amount of explosive adhering to the inside of a glass vial into which the explosive had been placed and then removed by vigorous tapping. In powdered form, most of the explosives--TNT, PETN, RDX, HMX, and TATP--exhibited similar spillage and adhesion to glass. However, PETN as sheet explosive and plasticized RDX (C-4), showed very little potential to contaminate surfaces, either by spillage or adhesion to glass.

Journal Article↗
PubMed2002

Explosibility boundaries for fly ash/pulverized fuel mixtures.

Incomplete combustion and subsequent fuel contamination of a waste stream can pose a serious explosion hazard. An example of this type of incident is the contamination of fly ash with unburned pulverized coal. The coal, if present in sufficient quantities in the mixture, can act as a fuel source for a potential explosion. Experiments were conducted in a 20l Siwek explosibility test chamber to determine the minimum fuel contamination of fly ash required to form an explosible mixture. A sample of fly ash from Ontario Power Generation (OPG) (Ont., Canada) was artificially contaminated with Pittsburgh pulverized coal dust (the surrogate used to represent unburned fuel dust). Additionally, the influence of fly ash particle size on the amount of fuel contaminant required to form an explosible mixture was examined. Fine and coarse size fractions of fly ash were obtained by screening the original sample of OPG fly ash. The results show that at least 21% Pittsburgh pulverized coal (or 10% volatile matter) was required to form an explosible mixture of the original fly ash sample and coal dust. The results also illustrate that fly ash particle size is important when examining the explosibility of the mixture. The fine size fraction of fly ash required a minimum of 25% coal dust (12% volatile matter) in the mixture for explosibility, whereas the coarse fly ash required only 10% coal dust (7% volatile matter). Thus, the larger the particle size of the inert fly ash component in the mixture, the greater the hazard.

Coal↗
PubMed2000

Explosive outbursts in children with Tourette's disorder.

OBJECTIVE: Sudden, explosive outbursts of behavior occur in some children with Tourette's disorder (TD). The etiology of these symptoms is unknown. This study investigated the relationship between explosive outbursts, TD, and its comorbid disorders. METHOD: Tic type and severity and the presence of specific comorbid disorders were compared in 37 children with TD and explosive outbursts and 31 children with TD who did not have such symptoms. RESULTS: Children with TD and explosive outbursts were more likely to demonstrate significant comorbid conditions, particularly attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, and oppositional defiant disorder. Tic type and severity did not appear related to the presence of explosive outbursts. A highly significant relationship was demonstrated between the number of comorbid psychiatric diagnoses and explosive outbursts. CONCLUSIONS: Explosive outbursts in children with TD resemble intermittent explosive disorder and may reflect dysregulation of diverse domains of brain function. The presence of such symptoms should alert the clinician to underlying comorbid conditions.

Adolescent↗
PubMed2003

Nonterrorist suicidal deaths involving explosives.

Suicidal deaths involving explosives unconnected to terrorism are rare. The investigation of deaths from explosive devices requires a multidisciplinary collaborative effort, as demonstrated in this study. Reported are 2 cases of nonterrorist suicidal explosive-related deaths with massive craniocerebral destruction. The first case involves a 20-year-old man who was discovered in the basement apartment of his father's home seconds after an explosion. At the scene investigators recovered illegal improvised power-technique explosive devices, specifically M-100s, together with the victim's handwritten suicide note. The victim exhibited extensive craniofacial injuries, which medicolegal officials attributed to the decedent's intentionally placing one of these devices in his mouth. The second case involves a 46-year-old man who was found by his wife at his home. In the victim's facial wound, investigators recovered portions of a detonator blasting cap attached to electrical lead wires extending to his right hand. A suicide note was discovered at the scene. The appropriate collection of physical evidence at the scene of the explosion and a detailed examination of the victim's history is as important as documentation of injury patterns and recovery of trace evidence at autopsy. A basic understanding of the variety of explosive devices is also necessary. This investigatory approach greatly enhances the medicolegal death investigator's ability to reconstruct the fatal event as a means of separating accidental and homicidal explosive-related deaths from this uncommon form of suicide.

Adult↗
PubMed2000

Audiometric configurations following exposure to explosions.

OBJECTIVE: To determine the configurations in pathologic audiograms obtained in patients shortly after exposure to an explosion. DESIGN, SETTING, AND PATIENTS: Audiograms were performed in 143 patients (286 ears; 76 males and 67 females, with a mean age of 34.6 years [range, 11-79 years]) sent to the Department of Otolaryngology and Head and Neck Surgery in a city hospital located in the center of Jerusalem, Israel, after being injured in 4 severe explosions occurring in Jerusalem during 1995-1997. Most of the audiograms were obtained within 4 hours after the explosion, and the remaining were obtained within 4 days of the explosion. RESULTS: Of 200 pathologic audiograms, 93 (46%) showed a downward slope configuration, 82 (41%) showed a dip configuration, and 25 (12%) were flat. There were 38 audiograms (19%) with 6-kHz dips. In 82% of the patients, the audiometric configurations were similar in both ears. Patients with a slope configuration on the audiogram were significantly older than those with a dip configuration (mean age, 40.8 vs 32.8 years; P<.01). CONCLUSIONS: There does not appear to be a single typical audiometric configuration in patients exposed to explosions. The slope and dip configurations are most frequently seen and are approximately equal in their incidence. This observation may lead to better understanding damage to the inner ear as a result of an explosion. This study is distinctive because of the large number of audiograms obtained and the fact that most of them were obtained immediately after the explosion.

Adolescent↗
PubMed2001

Fluorescence quenching as an indirect detection method for nitrated explosives.

A novel approach based on fluorescence quenching is presented for the analysis of nitrated explosives. Seventeen common explosives and their degradation products are shown to be potent quenchers of pyrene, having Stern-Volmer constants that generally increase with the degree of nitration. Aromatic explosives such as 2,4,6-trinitrotoluene (2,4,6-TNT) are more effective quenchers than aliphatic or nitramine explosives. In addition, nitroaromatic explosives are found to have unique interactions with pyrene that lead to a wavelength dependence of their Stern-Volmer constants. This phenomenon allows for their differentiation from other nitrated explosives. The fluorescence quenching method is then applied to the determination of hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazine(HMX), 2,4,6-TNT, nitromethane, and ammonium nitrate in various commercial explosive samples. The samples are separated by capillary liquid chromatography with post-column addition of the pyrene solution and detection by laser-induced fluorescence. The indirect fluorescence quenching method shows increased sensitivity and selectivity over traditional UV-visible absorbance as well as the ability to detect a wider range of organic and inorganic nitrated compounds.

Air Pollutants↗
PubMed1998

[Clinical characteristics of burn caused by coal mine explosion].

OBJECTIVE: To investigate the characteristics of the burn injury caused by coal mine explosion so as to enhance the cure rate. METHODS: Analyse the therapeutic result after planned standard treatment of clinical patients and review historical patients. RESULTS: 1. Coal mine explosion includes two types, i.e., gas explosion and coal dust explosion. 2. This kind of burn is a combined injury with pathologic changes of burns as the main feature. Mechanical injury is the chief cause of early death. Blast injury mainly damages the lungs. The occurrence of carboxyhemoglobinemia is not often. 3. The amount of fluid infusion in the first 24 h in exudation phase is 8% less of the traditional formula. Alkaline balanced salt solution is supplied as electrolyte solution, which can provide 45% of necessary HCO3- for correction of acidosis. 4. No thorough debridement is imposed in the treatment of burn wound. Baking with electric bulb with topical SD-Ag in semi-exposure state can be used. 5. Inhalation injury chiefly occurs in upper respiratory tract. The main bacterial species causing complicated lung infection are Pseudomonas aeruginosa and Staphylococcus aureus. 6. When MSOF occurs, the most frequently involved organ and system are the kidney and respiratory system. 7. The main bacteria causing systemic invasive infection are enteric bacilli and Pseudomonas aeruginosa. Enteric bacilli infection may be enterogenic. The latter infection is chiefly the result of cross infection in hospital. CONCLUSION: The burn caused by coal mine explosion is a combined injury characterized by pathologic changes of burn as the main issue. This kind of burn has two types, i.e., gas-explosion-burn and coal-dust-explosion-burn.

Adolescent↗
PubMed2001

Quantitative structure-activity relationships in enzymatic single-electron reduction of nitroaromatic explosives: implications for their cytotoxicity.

The mechanisms of cytotoxicity of polynitroaromatic explosives, an important group of environmental pollutants, remain insufficiently studied so far. We have found that the rate constants of single-electron enzymatic reduction, and the enthalpies of single-electron reduction of nitroaromatic compounds (DeltaHf(ArNO(2)(-*)), obtained by quantum mechanical calculation, may serve as useful tools for the analysis of cytotoxicity of nitroaromatic explosives with respect to the possible involvement of oxidative stress. The single-electron reduction rate constants of a number of explosives including 2,4,6-trinitrotoluene (TNT) and 2,4,6-trinitrophenyl-N-methylnitramine (tetryl), and model nitroaromatic compounds by ferredoxin:NADP(+) reductase (FNR, EC 1.18.1.2) and NADPH:cytochrome P-450 reductase (P-450R, EC 1.6.2.4) increased with a decrease in DeltaHf(ArNO(2)(-*)). This indicates that the reduction rates are determined by the electron transfer energetics, but not by the particular structure of the explosives. The cytotoxicity of explosives to bovine leukemia virus-transformed lamb kidney fibroblasts (line FLK) increased with a corresponding increase in their reduction rate constant by P-450R and FNR, or with a decrease in their DeltaHf(ArNO(2)(-*)). This points to an importance of oxidative stress in the toxicity of explosives in this cell line, which was further evidenced by the protective effects of desferrioxamine and the antioxidant N,N'-diphenyl-p-phenylene diamine, and an increase in lipid peroxidation. DT-diaphorase (EC 1.6.99.2) exerted a minor and equivocal role in the cytotoxicity of explosives to FLK cells.

Aniline Compounds↗
PubMed2003

Effects of bronchial intermittent constrictions on explosive flow during coughing in the dogs.

This study tested the hypothesis that intrathoracic bronchi intermittently constrict during coughing and attempted to elucidate the effect on explosive flow. The subjects were 21 dogs having undergone tracheostomy. In the first group A (n = 7), the diameter of the fifth-generation bronchus was measured with a balloon-tipped catheter and the change during coughing was analyzed. In the other group (n = 14), the dogs were vagotomized and coughing was simulated by sequential application of positive and negative airway pressures (sham cough). The effects of the bronchial constriction, elicited by the stimulation of vagus efferent fibers, on explosive flow and airway pressure of sham cough were analyzed. The bronchus was constricted in explosive phase of spontaneous coughing in all the dogs of the first group. When cough bouts were repetitively developed, bronchial constriction and phrenic burst developed simultaneously. The intermittent bronchial constrictions fused and virtually acted as tonic constriction. In the second group of dogs the explosive flow of sham cough consisted of two phases; a short bout followed by a near-constant flow. When the bronchus was constricted, the explosive flow was still biphasic in 12 dogs and an exponential decay pattern formed in 2 of them. In these 12 dogs, the peak explosive flow slightly but significantly decreased (mean +/- SD, 1.39 +/- 0.23 vs. 1.34 +/- 0.23 l/s) and airway pressure in the segmental bronchus became smaller (-1.18 +/- 0.53 vs. -0.15 +/- 0.94 cmH(2)O). We concluded that intermittent bronchial constrictions act as tonic one during coughing. Bronchial constriction slightly decreased the peak explosive flow and moved the choke point to the proximal airway.

Animals↗
PubMed2001

Determining explosivity part II: comparison of small-scale cartridge tests to actual pipe bombs.

The small-scale explosivity device (SSED) has been used to assess the explosive power of a number of low explosives-smokeless powders (WC-870, Red Dot, Bullseye, Winchester Action Pistol, and IMR-PB), Pyrodex, black powder, and an improvised explosive (TATP). The device requires 2 g of energetic material, a heavy-walled containment vessel, and a standard blast shield to permit use in most laboratories. The data from the SSED are compared with the fragmentation of pipe bombs which contained 300 to 700 g of powder. The SSED provided the same relative ordering of explosivity as suggested by the fragmentation of the real devices. In addition, the SSED was used to evaluate the chemical residue remaining after an explosion. Issues in using the device such as optimal detonators and restricted reaction volume were probed using three high explosives--TNT, Tetryl, and RDX.

Journal Article↗
PubMed2003

Water-soaked evidence: detectability of explosive traces after immersion in water.

Various factors governing the detectability of explosive traces after being soaked in water were studied. The variables are: the type of the surface (surfaces liable to be found in aircraft were chosen), the type of explosive, the type of water (tap or seawater), and movement of the immersed surface in the water. The maximal immersion times (tmax) after which explosive detection was possible were evaluated. This datum was found to depend on the type of explosive (one of the important factors is solubility in water), the surface material and the environmental conditions (tap or seawater movement). Detection of PETN on high-density polyethylene, linoleum, glass and aluminum, by the chemical Explosive Testing Kit (ETK), was possible even after a month of soaking in seawater. In addition, it has been found that movement of bulk water around the samples with deposited explosives considerably decreases tmax values. It is, therefore, recommended to retrieve samples for explosive analysis as soon as possible and in areas where the currents of water is minimal.

Journal Article↗
PubMed2003

A new model of blast injury from a spherical explosive and its special wound in the maxillofacial region.

OBJECTIVE: The goal of this study was to establish an efficient explosive model with spherical explosives for the study of blast injury and its wound characteristics in the maxillofacial region. METHODS: Different spherical explosives were used to produce blast waves and to establish the wound model. Fresh sheep heads as the targets were used for the study of wound characteristics. The wounding parameters and the injuries of targets after explosion were observed. RESULTS: The overpressure values of blast waves decreased exponentially along with the increase of distances to explosives and so did the tissue damage. The blast injury is quite different from other injuries and is more serious. A kind of special "split fracture" of the mandibles was found. CONCLUSIONS: The new explosive wound model with spherical explosives can be used for the study of blast injury in the laboratory. The injury manner of blast wave and the local anatomy of tissues resulted in the special wound characteristics.

Animals↗
PubMed1997

Explosion injuries in Finland 1991-1995.

BACKGROUND AND AIMS: Explosion injuries have been considered an increasing problem in many countries. This study describes the incidence and significance of injuries of this kind in Finland. MATERIAL AND METHODS: All explosion injuries in the Finnish hospital records from January 1991 to December 1995 were studied. RESULTS: A total of 493 persons (2.0 cases per 100,000 person-years) required hospital treatment for injuries caused by explosions. In addition to the injured, 14 persons died. Causes of the accidents were the following: various unspecified explosions in 32% of the cases, fireworks in 29%, explosive materials in 25%, and explosions of pressure vessels in 13%. The male to female ratio was 9:1, and the average age of the injured was 30 years. The injury profile showed soft tissue wounds in 26%, burns in 25%, ear and eye injuries in 23%, crush and traumatic amputations in 14%, fractures in 10%, and neurological in 2%. The average in-patient time was 11 days corresponding to altogether 5640 hospital days. CONCLUSIONS: Explosion injuries are epidemiologically not a great problem in comparison with all accidents, but neither can they be considered nowadays as a negligible medical problem in Finland.

Adult↗
PubMedDate not supplied

Explosion-related deaths in Sweden--a forensic-pathologic and criminalistic study.

All cases of death caused by explosions of explosive solids, fluids and gases in Sweden during the 6-year period 1979-1984 were analyzed. Among the total of 61 fatalities 33 (54%) were due to accidents (2/3 of them occupational and 1/3 miscellaneous accidents), 25 (41%) were suicides, and only 3 (5%) were associated with terrorist activity. About one half of the occupational accidents were caused by deficient safety devices or defective equipment, while the other half was due to transgression of regulations. All suicides were males, relatively elderly, the majority of them burdened with somatic and mental diseases, alcoholism, social or economical problems, most of them being familiar with explosives. The anatomical localization of suicidal explosive injuries was regular and symmetric, while the accidental and terrorist injuries showed great variations. The terrorist-associated deaths had common features different from all other death cases, strongly suggesting the same type of bomb and the same terrorist group. Explosives caused only superficial burns or singes. Symmetric hemorrhages of the vocal folds and fracture of the laryngeal skeleton were found, as well as ruptures of trachea and lungs. When not ruptured, the lungs showed to different types of injury: hyperinflation, probably due to the blast-induced barotrauma to the respiratory passages, or lung contusions. In cases of suspected terrorist explosions close collaboration between the forensic pathologists and police investigators is mandatory since the bodies of victims protect parts of the bomb from fire or from being spread over a larger area and thus constitute a part of the crime scene.

Accidents↗
PubMed1991

Toxicological investigation of liquid petroleum gas explosion: human model for propane/ethyl mercaptan exposures.

Four individuals died as the result of a propane explosion. As with many propane explosions, the question was raised as to the adequacy of the product's odorization after the autopsy studies had been conducted. In most cases, this question leads to litigation. Ethyl mercaptan is a widely used odorant for propane and was used in this instance. Three of the four victims had blood available at autopsy for study. Quantitative analyses of the victims' blood, obtained during autopsy, were performed using gas chromatography/mass spectrometry, without subjecting the samples to hydrolysis. These analyses determined the relative amounts of propane and ethyl mercaptan in the blood to be 90, 63, and 175 mL/m3 headspace, and 0.36, 0.34, and 0.77 microgram/L blood, respectively. Since mercaptans have been reported in human blood as products of metabolism, modeling studies were conducted to establish the validity of the autopsy data and to develop an autopsy toxicology protocol for investigating explosion deaths. When subjects were not exposed to an atmosphere containing ethyl mercaptan, dimethylsulfide was the only mercaptan detectable in their blood without severe hydrolysis prior to analysis. Metabolic ethyl mercaptan is sufficiently bound to be undetectable by the methods used without hydrolysis. Human subjects were exposed to a flammable mixture of air and propane odorized with ethyl mercaptan. The analyses of the blood from these subjects produced results which were comparable with those for the explosion victims, establishing that the question of odorant adequacy can be addressed at the autopsy of propane explosion victims. It is extremely important that the pathologist and toxicologist investigating gas explosion deaths recognize the valuable evidence existing in the victim's blood.

Autopsy↗