Environmental gas displacement: three accidental deaths in the workplace

Lessons Learned: Asphyxiation Hazard Associated with Dry Ice

Dry ice is widely used in the chemistry research settings as an excellent coolant. Herein, we report a case study of a graduate student researcher who lost consciousness while retrieving 180 lbs of dry ice from a deep dry ice container. We share the details of the incident and the lessons learned from it to promote safer handling of dry ice in these situations.

Suicide by Gaseous Displacement of Atmospheric Oxygen With Carbon Dioxide From Dry Ice Sublimation

ABSTRACT

Deaths from gaseous substances can occur from exposure to toxic gases or from accumulation of nontoxic gases that displace oxygen. We present a 38-year-old man with no known medical history, who was found deceased in a small bathroom with blankets and towels shoved under the door from the inside.At autopsy, the decedent was found to be in a moderate state of decomposition. There was mild pulmonary congestion, with no other significant findings. Standard postmortem toxicology on femoral blood was noncontributory.A search of the decedent's cell phone revealed statements and internet searches regarding carbon dioxide (CO 2 ) and asphyxia using dry ice. A journal entry also outlined a suicide plan using large amounts of dry ice, which was enacted by placing a laundry basket of dry ice into a bathtub containing water. Based on the investigation, the cause of death was determined to be asphyxia from displacement of oxygen with CO 2 .Dry ice sublimates into gaseous CO 2 , which quickly accumulates, with concentrations of 10% or more, rapidly becoming life-threatening. There are no pathognomonic autopsy findings seen in CO 2 -related asphyxia. In these circumstances, scene investigation is the most important factor in determining cause of death.

Carbon dioxide tolerability and toxicity in rat and man: A translational study

Background: Due the increasing need for storage of carbon dioxide (CO₂) more individuals are prone to be exposed to high concentrations of CO₂ accidentally released into atmosphere, with deleterious consequences.

Methods: We tested the effect of increasing CO₂ concentrations in humans (6–12%) and rats (10–50%) at varying inhalation times (10–60 min). In humans, a continuous positive airway pressure helmet was used to deliver the gas mixture to the participants. Unrestrained rats were exposed to CO₂ in a transparent chamber. In both species regular arterial blood gas samples were obtained. After the studies, the lungs of the animals were examined for macroscopic and microscopic abnormalities.

Results: In humans, CO₂ concentrations of 9% inhaled for >10 min, and higher concentrations inhaled for <10 min were poorly or not tolerated due to exhaustion, anxiety, dissociation or acidosis (pH < 7.2), despite intact oxygenation. In rats, concentrations of 30% and higher were associated with CO₂ narcosis, epilepsy, poor oxygenation and, at 50% CO₂, spontaneous death. Lung hemorrhage and edema were observed in the rats at inhaled concentrations of 30% and higher.

Conclusion: This study provides essential insight into the occurrence of physiological changes in humans and fatalities in rats after acute exposure to high levels of CO₂. Humans tolerate 9% CO₂ and retain their ability to function coherently for up to 10 min. These data support reconsideration of the current CO₂ levels (<7.5%) that pose a risk to exposed individuals (<7.5%) as determined by governmental agencies to ≤9%.

Deaths related to nitrogen inhalation: Analytical challenges

Dinitrogen (N₂) has been increasingly connected to suicidal deaths. The analysis of N₂ in post-mortem cases still represents a major challenge in forensic toxicology and circumstantial data has so far played a major role for the determination of the cause of death. In this paper, after presenting a review of cases of N₂ intoxication described in forensic literature, we report the application of two approaches in order to quantify an excess of N₂ in post-mortem whole blood collected from a case of suicide by nitrogen inhalation. N₂ analyses were performed by GC-MS on the suicidal case and on controls taken from 10 autopsy cases with similar PMI (5 traumatic deaths and 5 deaths by asphyxia). The percentage of N₂ was estimated by building a five-point N₂ peak area calibration curve (0, 15.6 %, 62.4 % 78.1 %, 100 %) and through an external QC, assessing linearity, accuracy and precision, LLOQ, specificity and stability of N₂ in the sample vial. Percentage of N₂ of the case was significantly higher than the post-mortem controls (p<0.05). The N₂/O₂ ratio of the case and controls was also calculated as an additional indicator, and was significantly higher in the case (p<0.05). The strengths and the limitation of both methods are reported in the paper. Toxicological confirmation for N₂ are rarely performed when the cause of death is evident, probably due to the lack of validated methods and the complexity of the interpretation of N₂ concentration in biological fluids. The presented methods can be rapidly and profitably applied with instrumentation normally available in forensic laboratories.

Cryopreservation without dry ice-induced acidification during sample transport

Dry ice (solid CO₂) remains highly useful when temperature-sensitive biological samples need to be cryogenically transported. CO₂ released during the sublimation of dry ice can diffuse through gas permeable receptacle material or any defective seals resulting in potential sample acidification and compromised integrity. In addition, the quality of cryopreservation can be undermined once the dry ice is exhausted. The dry ice carrier design described here has been demonstrated to prevent sublimated CO₂ from reaching the samples while maintaining storage temperature below -60 °C for 19 h. It is also equipped with microcontroller-based temperature monitoring for traceability and CO₂ gas monitoring for safety.

Lethal physiological effects of carbon dioxide exposure at high concentration in rats

The acute toxicity of high concentrations of carbon dioxide (CO₂) was investigated in anesthetized rats using physiological parameters. At an oxygen concentration of 21%, the survival time decreased in a concentration-dependent manner from ≥7.3 h at 20% CO₂ to 1.0 h at 50% CO₂. The animals were divided into groups that were exposed to 40% CO₂ and 21% O₂ balanced with nitrogen (CO₂ group), 40% CO₂ and 12.6% O₂ (CO₂-Hypoxia group), 0% CO₂ and 12.6% O₂ (Hypoxia group), and 0% CO₂ and 21% O₂ (Control group) for 3 h. In the CO₂ group, mean blood pressure (MBP) increased temporarily in the first 60 min followed by a gradual decrease, while breathing rate (BR) decreased immediately up to 3 h and the concentration of serum indicators reflecting organ damage increased. Most of these effects progressed in the CO₂-Hypoxia group. The Hypoxia group showed a contrasting response to the CO₂ groups in MBP and BR, and a slight partial increase in the serum indicators. Histological changes were not observed in any primary organs of any group, except for eosinophilic or necrosis of pyramidal cells in the hippocampal CA1 region of the CO₂ group. These results indicate that high concentrations of CO₂ inhalation are toxic, likely due to BR suppression, and that hypoxia produced under a high CO₂ environment, while showing little effect on its own, enhances the toxic effects of CO₂.

Investigation of CO2 Variation and Mapping Through Wearable Sensing Techniques for Measuring Pedestrians’ Exposure in Urban Areas

Citizens’ wellbeing is mainly threatened by poor air quality and local overheating due to human-activity concentration and land-cover/surface modification in urban areas. Peculiar morphology and metabolism of urban areas lead to the well-known urban-heat-island effect, characterized by higher air temperature in cities than in their surroundings. The environmental mapping of the urban outdoors at the pedestrian height could be a key tool to identify risky areas for humans in terms of both poor-air-quality exposure and thermal comfort. This study proposes urban environment investigation through a wearable miniaturized weather station to get the spatial distribution of key parameters according to the citizens’ perspective. The innovative system monitors and traces the field values of carbon dioxide (CO2) concentration, such as air temperature and wind-speed values, which have been demonstrated to be related to outdoor wellbeing. The presented monitoring campaign focused on a two-way, two-lane road in Rome (Italy) during traffic rush hours on both working days and weekends. Collected data were analyzed with respect to timing and position, and possible correlations among different variables were examined. Results demonstrated the wearable system capability to catch pedestrian-exposure variability in terms of CO2 concentration and local overheating due to urban structure, highlighting potentials in the citizens’ involvement as observation vectors to extensively monitor urban environmental quality.

Death in a Carbon Dioxide Therapy Bath: A Case Report and Review of the Literature

Carbon dioxide (CO₂) therapy is the subcutaneous or transcutaneous administration of CO₂ for therapeutic purposes. Carbon dioxide therapy is used for localized lipolysis, to treat chronic skin conditions, and is a safe treatment. Full-body CO₂ baths are offered in European spa centers, in which the clients are placed into full body bags infused with CO₂ at an optimal concentration range between 1000 and 1400 mg/L (516 000-722 500 ppm). Commercially manufactured, air-tight bags and accompanying apparatus designed to provide CO₂ baths can be purchased for home use. Few human CO₂-related deaths have been reported. They have been mostly accidental, consisting of persons trapped in a closed environment in the presence of "dry ice" or solid CO₂. There have been no reported deaths of a human undergoing a CO₂ therapy at home. We present a case of a middle-aged male found at home completely inside an air-sealed bag wrapped tightly around his body. The bag was connected to a working pump and a CO₂ gas tank. The pump was connected through an inflow and outflow circuit to the bag. The inflow tubing for CO₂ gas delivery was partially disrupted, while the outflow tubing was intact. The autopsy and toxicology were unremarkable. The cause of death was determined to be asphyxia by vitiated atmosphere as evident by the displacement of oxygen by CO₂ and low pressure created inside a "CO₂ therapy bath." The manner of death was accidental.

Fatal inhalation of nitrogen inside a closed environment: Toxicological issues about the cause of death

Asphyxia due to inhalation of nitrogen, as accidental or suicidal event, has been seldom reported in the forensic field. Death usually occurs because of a displacement and decrease of environmental and alveolar oxygen concentrations, but taking into account that nitrogen is a normal component of atmosphere, autopsy findings, which may be in certain cases unremarkable, must be corroborated with a careful scene investigation in order to determine the cause of death. We present a case of a 37-year old male found unresponsive inside his car with five liquid nitrogen tanks placed in the trunk, three of them with clear losses because of incomplete lock. Resuscitation efforts were unsuccessful. Autopsy findings and histological analyses were unremarkable, but toxicological analyses were crucial. Percentages of nitrogen were high in blood collected from the inferior vena cava (85.2%), left ventricle (81.01%) and the right lung (80.73%). Concentrations of nitrogen were higher than those detected in control samples: 14 autopsy cases, room air and water. The cause of death was identified as an inert gas asphyxiation, which was classified as accidental in accordance with the police report.

A Fatal Case of Gas Intoxication in Silage Pit

Fatalities due to gas intoxication are rare in routine forensic casework. The most common gas is carbon monoxide, with other gases (ammonia, methane, propane and butane, carbon dioxide, hydrogen sulfide) encountered only very rarely. In this report, we describe the accidental death of two maintenance workers who were found in the silage pit at a biogas plant. The autopsy revealed signs of asphyxia in both the deceased. Analysis of the gaseous mixtures in the tank using an infrared gas analyzer showed slightly elevated concentrations of carbon dioxide. Toxicological examination of the blood of both the deceased using gas chromatography with a flame ionization detector, spectrophotometry and liquid chromatography-mass spectrometry did not detect any toxicologically significant substance that would explain the sudden collapse. Both the autopsy and the toxicology analyses suggest CO₂ intoxication as the most likely cause for the collapse of the two men, which then led to sudden asphyxia.

Deaths from Environmental Hypoxia and Raised Carbon Dioxide

This paper reviews deaths in which there is an environment that is low in oxygen and/or has elevated levels of carbon dioxide. These deaths present problems to autopsy pathologists, as the autopsy is typically negative and postmortem toxicology cannot be used to detect the effects of hypoxia and raised levels of carbon dioxide. Deaths from hypoxia and raised carbon dioxide may be encountered in work-and nonwork-related environments. Typically these are accidents, but suicides may be encountered and criminal charges may follow these events. Environments that have been associated with these events include mines, tunnels, sewers, and pits. Transportation incidents may also be associated with hypoxic events, particularly aircraft and submarines. When an atmosphere low in oxygen is entered, collapse can be rapid, or immediate if the environmental oxygen is below 6%. Environments rich in carbon dioxide can also cause death, even with a high oxygen concentration. Such environments may be encountered in industrial settings, but also occur in natural disasters such as the Lake Nyos disaster. The identification of these deaths typically requires a coordinated investigation with safety inspectors and other experts in industrial- and work-related deaths.

Stomach Perforation Caused by Ingesting Liquid Nitrogen: A Case Report on the Effect of a Dangerous Snack

We report our experience with a case of stomach perforation after accidental ingestion of liquid nitrogen. A 13-year-old boy ate a snack at an amusement park and began to complain of sudden onset of severe abdominal pain with shortness of breath. It was determined that the snack he had ingested had been cooled with liquid nitrogen. A computed tomography scan of the abdomen and a chest X-ray showed a large volume of pneumoperitoneum. During surgery, a 4-cm perforation of the angularis incisura of the stomach was identified. Primary repair and omentopexy was performed. The patient was discharged without postoperative complications.

Murder-suicide by carbon dioxide (CO2) poisoning: a family case from Berlin, Germany

This report demonstrates how carbon dioxide (CO(2)) may be a potent weapon in murder-suicide, where the death scene offers virtually no clues as to the lethal modality and the autopsy findings are nonspecific. Four bodies were discovered in an apartment in midsummer 2012 in Berlin, Germany. The bodies were those of a father (a 69-year-old business consultant), his wife (aged 26-years), and two sons (aged 3 and 6 years, respectively). The police found the wife and two sons lying in their beds and the husband in a supine position on the floor with a plastic bag over his head tied loosely around his neck with a rope. A 500 g single-use CO(2) cylinder was standing on the floor. The container was almost empty and according to the label had been sold as a CO(2)-fertilizer for aquarium plants. Two synthetic inhalation face masks and tubing were also found, which tested positive for the DNA of all four deceased family members. It is hypothesized that the husband placed an inhalation mask over the mouths and noses of his wife and children while they were sleeping. Inhalation of pure CO(2) ensured their rapid unconsciousness due to hypercapnia and severe anoxia. The rapid increase in CO(2) concentration would render a victim helpless, with no time to wake and defend themselves, or others. The proximate cause of death in all cases was attributed to CO(2) intoxication, based on the scene findings, the reconstructed sequence of events, the autopsy, and results of toxicological studies.

Suicide by carbon dioxide

Suicides by self-poisoning are common in all parts of the world. Among these intoxications, gases are rarely used, especially carbon dioxide (CO2). Very few cases of self-inflicted and deliberate carbon dioxide poisonings have been reported. This paper presents two uncommon suicides by carbon dioxide intoxication. In one case, a 53-year-old man tightly sealed a small bathroom and locked himself in it likely with dry ice. Warning notices were tagged to the door. In another case, a 48-year-old man working in a restaurant committed suicide by closing himself in a walk-in refrigerator and opening the stored carbon dioxide containers intended for the beverage dispensing equipment. The limited possibilities of proving lethal CO2 intoxications post-mortem necessitate a close cooperation of the involved parties during investigation. Only the synopsis of all findings permits a sound assessment regarding the manner and cause of death.

Fatality in a wine vat

Intoxication with carbon dioxide (CO2), a nonexplosive, colorless, and odorless gas does not cause any clinical symptoms or signs, with the occasional exception of sudation. Carbon dioxide is principally used in the food industry (70% of CO2 production), in particular to preserve foods and to carbonate beverages. Most fatalities resulting from CO2 intoxication are accidental and occur either in closed spaces or when dry ice is used in the food industry. In this case report, a 42-year-old male winemaker engineer was found dead, his head inside a wine vat that had been filled with grapes on the previous day and supplemented with dry ice to improve the taste of wine.

A fatal case of CO(2) intoxication in a fermentation tank

Carbon dioxide (CO2 ) is an odorless constituent of air. Higher concentrations can be detected in geothermal and automotive emissions, fermentation, and sublimation of dry ice. An unskilled worker entered a fermentation tank to clean it, which had not been done for about 5 months allowing for high concentrations of CO2 to build up. A second worker entered the tank to rescue the first one. Shortly after both were found the first worker was rescued directly whereas the tank had to be rotated to pull the second worker out. Cardiopulmonary resuscitation was successful only for the first worker. Medico-legal autopsy showed bruises, hematoma, myocardial hemorrhage, and edema of the lungs. The right lung was vacuum degassed in an argon atmosphere and quadrupole-mass-spectrometry showed an elevated CO2 content in lung gases. Thus, CO2 intoxication/asphyxia in a vitiated atmosphere due to fermentation of wine mash was established as the cause of death.

Asphyxia Due to Accidental Nitrogen Gas Inhalation: A Case Report

Intoxications resulting from asphyxiate gases, such as nitrogen can cause hypoxia and even death. We present a case of a patient with nitrogen intoxication due to inadvertent industrial exposure. In this case, the patient survived and the outcome was different from those reported in the literature. For patients presenting to the emergency department from a workplace with a history of loss of consciousness after using of self-contained breathing apparatus, possibility of nitrogen or other simple asphyxiate gas intoxication should be considered seriously.

Suicide by oxygen deprivation with helium: a preliminary study of British Columbia coroner investigations

This article researches a relatively new suicide method advanced by right-to-die organizations: oxygen deprivation by breathing helium inside a plastic hood. The article begins with a review of the role of the coroner and the history of oxygen deprivation with helium; it then examines 20 Judgements of Inquiry (JOI) by British Columbia coroners into this form of suicide. The JOI were obtained through the Freedom of Information and Protection of Privacy Act and cover the period of 1999 to 2007. Findings raise concerns about the coding system used by coroners as well as adherence to internal documentation guidelines. The British Columbia Coroners Service (BCCS) has a public safety mandate to investigate all unnatural deaths and to make recommendations to prevent deaths in similar circumstances. It is a concern that BCCS has no recommendations to prevent suicides by oxygen deprivation with helium. More in-depth, systematic research is recommended to determine the prevalence of suicide by oxygen deprivation and to develop strategies to benefit public health and safety.

The debreather: a report on euthanasia and suicide assistance using adapted scuba technology

In response to the general prohibition of euthanasia and assisted suicide, some right-to-die activists have developed non-medical methods to covertly hasten death. One such method is a "debreather," a closed system breathing device that laypersons can use to induce hypoxia for persons seeking euthanasia or assisted suicide. This article presents data from nine cases where the debreather was used on humans, resulting in eight deaths. The covert properties of the debreather make it almost impossible for medical examiners and law enforcers to detect its use. Clandestine behavior circumvents legal forms of social control and challenges models for regulated, medicalized euthanasia and assisted suicide. The debreather compromises the ability of forensic investigators to assign an accurate cause and manner of death, and this raises implications for law enforcement, vital statistics, and research into the causes of death. The involvement of lay organizations in euthanasia and assisted suicide means that effective social policy on right-to-die issues must take into account their activities as well as those of other health professionals.

A carbon dioxide fatality from dry ice

This report documents a rare case of carbon dioxide intoxication in a young healthy male. The deceased hid in a small plastic container, size 1.5 x 1 x 1 m, and within 5 min he was located suffering convulsions and was reported as dead within minutes. Scene investigation revealed dry ice in the container. Autopsy findings were unremarkable. The probable cause of the convulsions was carbon dioxide intoxication due to both the dry ice sublimation and the small confined space in which he was hiding. This report emphasizes the significance of scene investigation in establishing the cause of the death.

Asphyxiation due to dry ice in a walk-in freezer

BACKGROUND

Exposure to a high concentration of environmental carbon dioxide (CO2) can result in poisoning through direct toxicity and by displacing atmospheric oxygen (O2). Dry ice undergoes sublimation to a gaseous state at -78.5 degrees C (-109.3 degrees F), which is heavier than air and can accumulate in dependent areas.

CASE REPORT

We report the case of a 59-year-old man found in cardiac arrest shortly after entering a recently repaired walk-in freezer that contained dry ice. First responders and bystanders did not recognize the proximate hazardous environment but were fortunately uninjured. A careful Emergency Department history coupled with rapid case investigation by the Medical Examiner's Office led to the determination of the cause of death and the elimination of the ongoing hazard.

CONCLUSION

This case illustrates the lethal consequences of improper storage of dry ice and the need to consider toxic environmental exposure as a cause of sudden cardiac arrest.

An apple a day does not always keep the doctor away

The authors describe a case of suicide in the workplace. A 45-year-old man employed by a fruit and vegetable packing company was found dead in a room containing a modified atmosphere for the packaging of fruits and vegetables. The rescue team measured the carbon monoxide (CO) concentration of the ambient air with a digital CO tester and found a level higher than 600 particles per million. Analysis of an arterial blood sample taken with an airtight syringe revealed the absence of CO but high levels of carbon dioxide (CO(2)). Autopsy revealed no significant injury and police investigators found a handwritten note of intent, describing a recent personal crisis. The authors concluded that the cause of death was suicide by asphyxiation secondary to CO(2) intoxication and notably oxygen (O(2)) depletion. This manner of suicide is rare and most cases previously described in the literature were accidental intoxications. To the best of our knowledge, this is the first case of suicide by CO(2) intoxication and O(2) depletion in a room with a modified atmosphere.

Evaporated liquid nitrogen-induced asphyxia: a case report

A 27-yr-old postgraduate student was found lying at the floor of an unsealed underground dry area, where a valve-opened empty cylinder of liquid nitrogen (150 L) was connected to a cap-removed empty Dewar-flask (10 L) via a copper infusion tube. No injury was found externally or internally. There were petechiae in the bilateral conjunctivae and periorbital skin. The dry area, measuring 300 x 130 x 260 cm, had a communication to the basement of the research building by a window measuring 90 x 60 cm in size at 130 cm above the floor. The scene reconstruction and atmosphere gas analysis revealed that the O2 concentration at 60 cm above the base dropped to 12.0% in 3 min and 10 sec, 10.0% in 8 min and 53 sec, 6.0% in 18 min and 40 sec, and 4.2% in 20 min and 28 sec. The primary cause of death was asphyxia by evaporated liquid nitrogen.

Carbon dioxide poisoning

Carbon dioxide is a physiologically important gas, produced by the body as a result of cellular metabolism. It is widely used in the food industry in the carbonation of beverages, in fire extinguishers as an 'inerting' agent and in the chemical industry. Its main mode of action is as an asphyxiant, although it also exerts toxic effects at cellular level. At low concentrations, gaseous carbon dioxide appears to have little toxicological effect. At higher concentrations it leads to an increased respiratory rate, tachycardia, cardiac arrhythmias and impaired consciousness. Concentrations >10% may cause convulsions, coma and death. Solid carbon dioxide may cause burns following direct contact. If it is warmed rapidly, large amounts of carbon dioxide are generated, which can be dangerous, particularly within confined areas. The management of carbon dioxide poisoning requires the immediate removal of the casualty from the toxic environment, the administration of oxygen and appropriate supportive care. In severe cases, assisted ventilation may be required. Dry ice burns are treated similarly to other cryogenic burns, requiring thawing of the tissue and suitable analgesia. Healing may be delayed and surgical intervention may be required in severe cases.

Sudden death due to asphyxia by esophageal polyp: two case reports and review of asphyxial deaths

Asphyxia, not an uncommon cause of sudden death, may result from numerous etiologies. Foreign-body aspiration and strangulation are 2 extrinsic causes. Airway obstruction may also be caused by laryngeal edema, asthma, infection, or anaphylaxis. Chronic causes of asphyxia include musculoskeletal diseases (eg, muscular dystrophy, amyotrophic lateral sclerosis), neurologic disorders (eg, myasthenia gravis, multiple sclerosis), respiratory disease (eg, emphysema, chronic bronchitis), or tumors. The manner of death in cases of asphyxiation may be natural, accidental, homicide, or suicide. For the death investigator, determining the cause and manner of death can often be quite challenging. We report here 2 cases of an esophageal fibrovascular polyp causing sudden asphyxial death, review of the literature, and discussion of other differential diagnoses in the case of asphyxial death.

Analytical investigations in a death case by suffocation in an argon atmosphere

A 31-year-old engineer was found dead in a reaction vessel (diameter 0.8 m, height 1.8 m) of a bulb factory some minutes after he had entered it for repair work. Resuscitation attempts with artificial respiration were unsuccessful. Despite autopsy and usual toxicological analyses, no cause of death could be found. Since in the normal production process, argon was used as a protecting gas, the possibility of suffocation in an argon atmosphere was investigated. This was rendered more difficult because of the natural content of 0.93 vol.% argon in air and since the excessive argon could have been removed by the resuscitation attempts. Gas samples from larynx, esophagus, bronchi, and stomach, separated blood samples from both ventricles of the heart and from the vena iliaca externa as well as tissue samples from lung and liver were collected during autopsy into headspace vials in such a way that the loss of gas and a dilution by surrounding air was avoided as far as possible. The samples were analyzed by headspace GC-MS. The abundance of Ar+ (m/z = 40) was used for quantification with N2(2+) (m/z = 14) as internal standard. The following argon concentrations were measured (mean values, case under investigation/comparison cases): gas from larynx 1.79/0.96 vol.%, stomach gas 1.58/0.89 vol.%, heart blood (left ventricle) 7.2/2.7 microg/mL, heart blood (right ventricle) 5.8/2.7 microg/mL, blood from vena iliaca externa 3.6/2.7 microg/mL. A clearly increased concentration was also found in lung tissue, whereas in liver tissue no significant difference in comparison to other cases was measured. From the results, it follows that the deceased inhaled an increased amount of argon a short time before death. The concentrations are consistent with asphyxia and subsequent resuscitation attempts. They cannot be explained by a long-term inhalation of an atmosphere enriched with argon before the incident as it is likely to have occurred in this factory hall.

Exposure to extremely high concentrations of carbon dioxide: a clinical description of a mass casualty incident

Clinical reports on unintentional mass exposure to extreme concentrations of carbon dioxide are rare. We describe an industrial incident caused by a container of liquid carbon dioxide that was unintentionally opened in an enclosed working environment. Twenty-five casualties reached our emergency department. Symptoms included dyspnea, cough, dizziness, chest pain, and headache. ECGs (n=15) revealed ST-segment changes in 2 (13.3%) patients, atrial fibrillation in 2 patients, and non-Q wave myocardial infarction in 1 patient. Chest radiographs (n=22) revealed diffuse or patchy alveolar patterns, consistent with pneumonitis, in 6 (27%) patients and pulmonary edema in 2 (9%) patients. Eleven (44%) patients were admitted to the hospital: 8 were discharged 24 hours later and the others within 8 days. No patient died. Exposure to high concentrations of carbon dioxide resulted in significant but transient cardiopulmonary morbidity with no mortality when victims were promptly evacuated and given supportive therapy. Cardiac complications were frequently observed and should be actively sought.