Bedford Colliery disaster

Woolley was removing pit props when the fracturing roof released firedamp. The flame in Woolley's Davy lamp turned blue indicating explosive gas. Instead of reporting it, work continued. A few minutes later the flame in the lamp of a nearby miner "fired". Established procedure was "lowering his lamp to the floor [firedamp is lighter than air] and taking it steadily into the fresh air, avoiding jerks". Instead the miner shook it and attempted to blow it out at which point the flame passed through the gauze and caused the explosion. The verdict of the coroner's jury was accidental death caused by an explosion of firedamp.

Common carotid artery

carotidcarotid arteriescarotid artery
In anatomy, the left and right common carotid arteries (carotids) are arteries that supply the head and neck with oxygenated blood; they divide in the neck to form the external and internal carotid arteries.

Hypoxia (medical)

Such situations may lead to unconsciousness without symptoms since carbon dioxide levels are normal and the human body senses pure hypoxia poorly. A similar problem exists when inhaling certain odorless asphyxiant gases. Asphyxiant gases reduce/displace the normal oxygen concentration in breathing air, where prolonged exposure to this hypoxic breathing gas leads to unconsciousness, followed by death by inert gas asphyxiation (suffocation). When oxygen level dips below 19.5% v/v, the air is considered oxygen-deficient, where oxygen concentrations below 16% volume are considered highly dangerous for humans.


Wallsend-on-TyneMunicipal Borough of WallsendNewcastle
Wallsend, historically Wallsend on Tyne, is a town in North Tyneside, Tyne and Wear, North East of England. Historically part of Northumberland, Wallsend derives its name as the location of the end of Hadrian's Wall. It has a population of 42,842 and lies 3.5 mi east of Newcastle City Centre. The population of the Wallsend ward of the North Tyneside Borough was at the 2011 census 10,304.

Silicon dioxide

silicasiliceousSiO 2
Simply heating TEOS at 680–730 °C gives the dioxide: ::Si(OC 2 H 5 ) 4 → SiO 2 + 2 O(C 2 H 5 ) 2 Similarly TEOS combusts around 400 °C: ::Si(OC 2 H 5 ) 4 + 12 O 2 → SiO 2 + 10 H 2 O + 8 CO 2 TEOS undergoes hydrolysis via the so-called sol-gel process. The course of the reaction and nature of the product are affected by catalysts, but the idealized equation is: ::Si(OC 2 H 5 ) 4 + 2 H 2 O → SiO 2 + 4 HOCH 2 CH 3 Being highly stable, silicon dioxide arises from many methods. Conceptually simple, but of little practical value, combustion of silane gives silicon dioxide. This reaction is analogous to the combustion of methane: ::SiH 4 + 2 O 2 → SiO 2 + 2 H 2 O.

Shortness of breath

dyspnearespiratory distressdyspnoea
Chemoreceptors in the carotid bodies and medulla supply information regarding the blood gas levels of O 2, CO 2 and H + . In the lungs, juxtacapillary (J) receptors are sensitive to pulmonary interstitial edema, while stretch receptors signal bronchoconstriction. Muscle spindles in the chest wall signal the stretch and tension of the respiratory muscles. Thus, poor ventilation leading to hypercapnia, left heart failure leading to interstitial edema (impairing gas exchange), asthma causing bronchoconstriction (limiting airflow) and muscle fatigue leading to ineffective respiratory muscle action could all contribute to a feeling of dyspnea.


acidemiaacidaemiablood acidosis
Respiratory acidosis results from a build-up of carbon dioxide in the blood (hypercapnia) due to hypoventilation. It is most often caused by pulmonary problems, although head injuries, drugs (especially anaesthetics and sedatives), and brain tumors can cause this acidemia. Pneumothorax, emphysema, chronic bronchitis, asthma, severe pneumonia, and aspiration are among the most frequent causes. It can also occur as a compensatory response to chronic metabolic alkalosis. One key to distinguish between respiratory and metabolic acidosis is that in respiratory acidosis, the CO 2 is increased while the bicarbonate is either normal (uncompensated) or increased (compensated).


The exact increase required is determined by the respiratory gases homeostatic mechanism, which regulates the arterial P O 2 and P CO 2 . This homeostatic mechanism prioritizes the regulation of the arterial P CO 2 over that of oxygen at sea level. That is to say, at sea level the arterial P CO 2 is maintained at very close to 5.3 kPa (or 40 mmHg) under a wide range of circumstances, at the expense of the arterial P O 2, which is allowed to vary within a very wide range of values, before eliciting a corrective ventilatory response.

Water vapor

water vapourvaporevaporation
When combined with its quantity, water vapor then has a relevant dew point and frost point, unlike e. g., carbon dioxide and methane. Water vapor thus has a scale height a fraction of that of the bulk atmosphere, as the water condenses and exits, primarily in the troposphere, the lowest layer of the atmosphere. Carbon dioxide and methane, being non-polar, rise above water vapor. The absorption and emission of both compounds contribute to Earth's emission to space, and thus the planetary greenhouse effect. This greenhouse forcing is directly observable, via distinct spectral features versus water vapor, and observed to be rising with rising levels.

Trimdon Grange

The Trimdon Grange ExplosionTrimdon Grange colliery disasterTrimdon Grange Explosion
After the explosion the burnt methane (firedamp) forms carbon dioxide (then called carbonic acid gas) and carbon monoxide. The resulting mixture is called afterdamp and will suffocate and kill. Indeed, the gas forced its way through a passage into the adjoining Kelloe Pit where six men lost their lives from the afterdamp. The incident was recounted in the song "Trimdon Grange Explosion" by the local collier-bard Thomas "Tommy" Armstrong. Armstrong performed the song within a few days of the disaster in the local Mechanics' Hall.

Pulmonary contusion

lung contusionblast lungbruised lungs
In normal gas exchange, carbon dioxide diffuses across the endothelium of the capillaries, the interstitial space, and across the alveolar epithelium; oxygen diffuses in the other direction. Fluid accumulation interferes with gas exchange, and can cause the alveoli to fill with proteins and collapse due to edema and bleeding. The larger the area of the injury, the more severe respiratory compromise will be. Pulmonary contusion can cause parts of the lung to consolidate, alveoli to collapse, and atelectasis (partial or total lung collapse) to occur.


Diffusion of oxygen and carbon dioxide takes place across the walls of the smallest tubes, called tracheoles, which penetrate tissues and even indent individual cells. Gas may be conducted through the respiratory system by means of active ventilation or passive diffusion. Unlike vertebrates, insects do not generally carry oxygen in their haemolymph. This is one of the factors that may limit their size. A tracheal tube may contain ridge-like circumferential rings of taenidia in various geometries such as loops or helices. Taenidia provide strength and flexibility to the trachea. In the head, thorax, or abdomen, tracheae may also be connected to air sacs.


barometricaneroid barometerbarometers
Thus low pressure increases the risk of firedamp accumulating. Collieries therefore keep track of the pressure. In the case of the Trimdon Grange colliery disaster of 1882 the mines inspector drew attention to the records and in the report stated "the conditions of atmosphere and temperature may be taken to have reached a dangerous point". Aneroid barometers are used in scuba diving. A submersible pressure gauge is used to keep track of the contents of the diver's air tank. Another gauge is used to measure the hydrostatic pressure, usually expressed as a depth of sea water. Either or both gauges may be replaced with electronic variants or a dive computer.

Guard (grappling)

guardbutterfly guardfull guard
In pure grappling combat sports, the guard is considered an advantageous position, because the bottom combatant can attack with various joint locks and chokeholds, while the top combatant's priority is the transition into a more dominant position, a process known as passing the guard. In mixed martial arts competition or hand-to-hand combat in general, it is possible to effectively strike from the top in the guard, even though the bottom combatant exerts some control. There are various types of guard, with their own advantages and disadvantages. The guard is a key part of Brazilian Jiu-Jitsu where it can be used as an offensive position.

Sentinel species

canary in a coal minecanary in the coal mineanimal sentinel
The idea of placing a canary or other warm blooded animal in a mine to detect carbon monoxide was first proposed by John Scott Haldane, in 1913 or later. Well into the 20th century, coal miners brought canaries into coal mines as an early-warning signal for toxic gases, primarily carbon monoxide. The birds, being more sensitive, would become sick before the miners, who would then have a chance to escape or put on protective respirators. In Minamata Bay, Japan, cats developed "dancing cat fever" before humans were affected due to eating mercury-contaminated fish. Dogs were recognized as early as 1939 to be more susceptible to tonsil cancer if they were kept in crowded urban environments.

Respiratory system

respiratoryrespirationrespiratory organs
Most of the carbon dioxide in the blood is carried as bicarbonate ions (HCO 3 − ) in the plasma. However the conversion of dissolved CO 2 into HCO 3 − (through the addition of water) is too slow for the rate at which the blood circulates through the tissues on the one hand, and through alveolar capillaries on the other. The reaction is therefore catalyzed by carbonic anhydrase, an enzyme inside the red blood cells. The reaction can go in both directions depending on the prevailing partial pressure of CO 2 . A small amount of carbon dioxide is carried on the protein portion of the hemoglobin molecules as carbamino groups.

List of mining disasters in Lancashire

spate of disasters
Most fatalities were caused by firedamp, some caused by the miners who took the tops off the safety lamps that were designed to protect them because of the poor light they gave out. Some mineowners turned a blind eye to the use of candles in even the gassiest coal seams. To regulate working conditions, the government passed Acts of Parliament: the 1842 Act prohibited the employment of females and boys under 10 years old and appointed a single inspector, but inspections were few and breaches were common. Acts passed in subsequent years led to the appointment of more inspectors and increased their powers to regulate how mines were operated and the working conditions and welfare of the miners.

Felling, Tyne and Wear

FellingFelling mining disastersFelling-on-Tyne
The colliery was the site of two mining disasters which cost over one hundred lives, helping prompt Sir Humphry Davy and George Stephenson to develop their safety lamps (there is a monument to the workers lost in St Mary's churchyard, Heworth). Other heavy industry took root in the 18th and 19th centuries so that Felling developed from a rural scattering of villages into firstly three distinct settlements at Low and High Felling and Felling Shore, then in 1894 these amalgamated with other local villages into the town of Felling, administered by the Felling Urban District Council at Sunderland Road.

Coal seam fire

mine fireburning coal seamscoal field fire
China's coal fires, which consume an estimated 20 – 200 million tons of coal a year, make up as much as 1 percent of the global carbon dioxide emissions from fossil fuels. One of the most visible changes will be the effect of subsidence upon the landscape. Another local environmental effect can include the presence of plants or animals that are aided by the coal fire. The prevalence of otherwise non-native plants can depend upon the fire's duration and the size of the affected area.

Mammoth Mine disaster

Frick mine explosion
The entrance and a memorial to the miners killed in the accident are located behind the Mount Pleasant (PA) Township Municipal Authority building, which was formerly the lamp-house, where miners' safety lamps were stored and distributed. Johnstown Flood of 1889. Morewood PA massacre, April 1891. Mammoth mine explosion historical marker. Vivian, Cassandra. The Hidden History of the Laurel Highlands. The History Press. Charleston SC. 2014. p. 36, 38.

Death of Eugene Ejike Obiora

Eugene Ejike Obiora
The report notes that point bleeding, internal bleeding of the neck muscles, as well as fracture of the thyroid cartilage all occurred as results of the chokehold, and then goes on to conclude that the injuries caused shortness of breath, but that they alone did not cause suffocation. The Special Unit in summary finds that there has not been consciously performed "any one act which stopped/hindered" Obiora from breathing. The report goes on stating that it cannot be ruled out that Obiora's death "could have been avoided if the officers had had knowledge about possible dangers of using the stomach position".