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[[Image:Illu capillary.jpg|thumb|300px|Blood flows from the heart to [[artery|arteries]], which narrow into [[arteriole]]s, and then narrow further still into capillaries. After the tissue has been [[perfusion|perfused]], capillaries widen to become venules and then widen more to become veins, which return blood to the heart.]]
The '''Bhopal disaster''' was an [[industrial disaster]] that occurred in the city of [[Bhopal]], [[Madhya Pradesh]], [[India]], resulting in the immediate deaths of more than 3,000 people, according to the Indian Supreme Court. A more probable figure is that 8,000 died within two weeks, and it is estimated that the same number have since died from gas related diseases<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref>.
'''Capillaries''' are the smallest of a body's [[blood vessel]]s, measuring 5-10 [[micrometre|μm]] in diameter, which connect [[arteriole]]s and [[venule]]s, and enable the interchange of [[water]], [[oxygen]], [[carbon dioxide]], and many other [[nutrient]] and [[waste]] [[chemical]] substances between [[blood]] and surrounding [[tissue (biology)|tissue]]s.<ref>{{cite book
| last = Maton
| first = Anthea
| authorlink =
| coauthors = Jean Hopkins, Charles William McLaughlin, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Wright
| title = Human Biology and Health
| publisher = Prentice Hall
| date = 1993
| location = Englewood Cliffs, New Jersey
| pages =
| url =
| doi =
| id =
| isbn = 0-13-981176-1}}</ref>


==Anatomy==
The incident took place in the early hours of the morning of December 3, 1984, in the heart of the city of [[Bhopal]] in the [[India]]n state of [[Madhya Pradesh]]. A [[Union Carbide]] subsidiary [[pesticide]] plant released 43 [[tonne]]s of [[methyl isocyanate]] (MIC) gas, exposing at least 520,000 people to toxic gases. The Bhopal disaster is frequently cited as the world's worst [[industrial disaster]].<ref name=Eckerman2001/><ref name=Eckerman2004/><ref name=Chouhan>Chouhan ''et al.'' (1994, 2005).</ref><ref>{{cite web |publisher = [[Greenpeace]] |title = Bhopal - The world's worst industrial disaster |url = http://www.greenpeace.org/international/photosvideos/slideshows/bhopal-the-world-s-worst-ind}}</ref><ref>{{cite news |publisher = [[Australian Broadcasting Corporation]] |author = Simi Chakrabarti |url = http://www.abc.net.au/worldtoday/content/2004/s1257352.htm |title = 20th anniversary of world's worst industrial disaster}}</ref> The [[International Medical Commission on Bhopal]] was established in 1993 to respond to the disasters.
Blood flows from the heart to arteries, which branch and narrow into arterioles, and then branch further still into capillaries. After the tissue has been perfused, capillaries join and widen to become venules and then widen more to become veins, which return blood to the heart.


The "capillary bed" is the network of capillaries supplying an [[organ (biology)|organ]]. The more [[Metabolism|metabolically]] active the cells, the more capillaries it will require to supply nutrients and carry away waste products.
==Background and causes, summary==
The [[Union Carbide India, Limited]] (UCIL) plant was established in 1969. 51% was owned by Union Carbide Corporation (UCC) and 49% by Indian authorities. It produced the pesticide [[carbaryl]] (trade mark Sevin). [[Methyl isocyanate]] (MIC), an intermediate in carbaryl manufacture, was used instead of less toxic but more expensive materials. In 1979, a plant for producing MIC was added. UCC was responsible for all technique and design. The plant was located close to a densely populated area, instead of on the other side of the town where UCIL was offered an area. MIC was stored in a few large tanks instead of several small tanks.


[[Metarteriole]]s provide direct communication between arterioles and venules and are important in bypassing the bloodflow through the capillaries. True capillaries branch mainly from metarterioles and provide exchange between cells and the circulation. The internal diameter of 8 μm forces the red [[blood cell]]s to partially fold into bullet-like shapes in order to by
During the night of December 3rd 1984, large amounts of water entered tank 610, containing 43 tonnes of methyl isocyanate. The resulting reaction generated a major increase in the temperature of liquid inside the tank to over 400°F (200°C). The MIC holding tank then gave off a large volume of toxic gas, forcing the emergency release of pressure. The reaction was sped up by the presence of iron from corroding non-stainless steel pipelines.
pass them in single file.


Precapillary [[sphincter]]s are rings of [[smooth muscle]]s at the origin of true capillaries that regulate blood flow into true capillaries and thus control blood flow through a tissue.
There have been several theories on the reason for the entry of water into the tank. The workers claim that, because of the bad maintenance with leaking valves etc, it was possible for the water to climb from the point where the pipeline washing was performed to tank 610<ref name=Chouhan>Chouhan ''et al.'' (1994, 2005).</ref>. UCC maintains that this was not possible, and that it was an act of sabotage by a "disgruntled worker" who introduced water directly into the tank. There is much confusion because the Indian government closed the plant to outsiders and would not allow interviews with the plant employees for almost a year. Much speculation arose in the meantime and much of it was not scientifically based, but based on worker accounts which may or may not have been accurate.


===Types===
The deciding factors that caused the outcome were the state of the art plant design (location near a densely populated area, using hazardous chemicals instead of less dangerous, storing in large tanks, possible corroding material in pipelines etc), and the decision to close the plant which began a shut down which contributed to poor oversight by local managers (poor oversight of operators, safety systems not functioning etc), and in the aftermath, negligence on the part of the governments of India and Madhya Pradesh as well as UCC<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Eckerman2005>Eckerman (2005).</ref>.
Capillaries come in three types:
*Continuous - Continuous capillaries have a sealed endothelium and only allow small molecules, like water and ions to diffuse. Continuous capillaries can be further divided into two subtypes:
:# Those with numerous transport vesicles and [[tight junction]]s that are primarily found in skeletal muscles, lungs, gonads, and skin.
:# Those with few vesicles and tight junctions that are primarily found in the central nervous system.
*Fenestrated - Fenestrated capillaries (derived from "fenestra," the [[Latin]] word for "window") have pores in the the endothelial cells (60-80 nm in diameter) that are spanned by a diaphragm of radially oriented fibrils and allow small molecules <ref>{{BUHistology|22401lba}}</ref><ref>{{cite book | title = Functional Ultrastructure: An Atlas of Tissue Biology and Pathology| author = Pavelka, Margit; Jürgen Roth| publisher = Springer | year = 2005 | page = 232}}</ref> and limited amounts of protein to diffuse. In the renal glomerulus there are larger fenestrae which have no diaphragms. Both types of fenestrated blood vessels have continuous basal lamina and are primarily located in the endocrine glands, intestines, pancreas and glomeruli of kidney.
*[[Sinusoid (blood vessel)|Sinusoidal]] - Sinusoidal or discontinuous capillaries are special fenestrated capillaries that have larger openings (30-40 μm in diameter) in the epithelium to allow [[red blood cell]]s and serum proteins to enter, a process that is aided by a discontinuous basal lamina. These capillaries lack pinocytotic vesicles and gaps may be present in cell junctions permitting leakage between endothelial cells. Sinusoid blood vessels are primarily located in the liver, spleen, bone marrow, lymph nodes, and adrenal cortex.


==Physiology==
==Contributing Factors==
[[Image:Illu_capillary_microcirculation.jpg|right]]
The capillary wall is a one-layer endothelium so thin that gas and molecules such as [[oxygen]], [[water]], [[proteins]] and [[lipids]] can pass through them driven by osmotic and hydrostatic gradients. Waste products such as [[carbon dioxide]] and [[urea]] can diffuse back into the [[blood]] to be carried away for removal from the body. The physics of this exhange is explained by the [[Starling equation]].


The capillary bed usually carries no more than 25% of the amount of blood it could contain, although this amount can be increased through [[auto regulation]] by inducing relaxation of [[smooth muscle]] in the arterioles that lead to the capillary bed as well as constriction of the metarterioles.
*The deficiencies in the Bhopal plant design can be summarised as: choosing a dangerous method of manufacturing pesticides; large-scale storage of MIC prior to selling; location close to a densely populated area; under-dimensioning of the safety features; dependence on manual operations.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref>.
* Deficiencies in the management of UCIL can be summarised: lack of skilled operators because of the staffing policy; reduction of safety management because of reducing the staff; insufficient maintenance of the plant; lack of emergency response plans.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Eckerman2006>Eckerman (2006).</ref>


The capillaries do not possess this smooth muscle in their own wall, and so any change in their [[diameter]] is passive. Any signaling molecules they release (such as [[endothelin]] for constriction and [[nitric oxide]] for dilation) act on the smooth muscle cells in the walls of nearby, larger vessels, e.g. [[arterioles]].
===Plant Location===
A long-term cause of the catastrophe was the location of the plant; authorities had tried and failed to persuade Carbide to build the plant away from densely-populated areas. Carbide explained their refusal on the expense that such a move would incur.<ref name=Eckerman2004/><ref name=Kovel>Kovel (2002).</ref>


Capillary [[vascular permeability|permeability]] can be increased by the release of certain [[cytokines]], such as in an [[immune response]].
===Plant production process===
Union Carbide produced their pesticide, Sevin (the name of [[carbaryl]]), using MIC as an intermediate. Until 1979, MIC was imported from USA.<ref name=Eckerman2004/> Other manufacturers, such as [[Bayer]], made Sevin without MIC, though at greater manufacturing costs.<ref name=Kovel/>


[[Starling equation]] is a mathmatical model for fluid movement across capillaries:
The Bhopal route was to react [[methyl amine]] with [[phosgene]] (also a deadly gas & chemical warfare agent) to form MIC, the MIC was then reacted with [[1-naphthol]] to form the final product. This route is different to the MIC free route used elsewhere with the same raw materials in a different manufacturing order: phosgene is reacted with the naphthol first to form a chloroformate ester which is then reacted with methyl amine.
Jv=Kf[(Pc-Pi)-(pc-pi)]
where:
Jv = fluid movement (ml/min)
Kf = hydraulic conductance (ml/min. mmHg)
Pc = Capillary hydrostatic pressure
Pi = Interstetial hyrdostatic pressure
pc = capillary oncotic pressure
pi = interstestial oncotic pressure.
===Immune response===
In an [[immune system|immune]] response, the [[endothelium|endothelial cells]] of the capillary will upregulate [[cell receptor|receptor]] molecules, thus it signals the need for an immune response by the site of [[infection]] and aids [[extravasion]] of these cells into the tissue.


==History==
It seems as at least some of the techniques were more or less unproven.<ref>{{cite web |url=http://www.bhopal.net/oldsite/unproventechnology.html|title=Unproven Technology|accessdate=2008-04-11 |date=2002-11-14}}</ref>
[[Ibn al-Nafis]] theorized a "premonition of the capillary circulation in his assertion that the [[pulmonary vein]] receives what comes out of the [[pulmonary artery]], this being the reason for the existence of perceptible passages between the two."<ref name=Paul>Dr. Paul Ghalioungui (1982), "The West denies Ibn Al Nafis's contribution to the discovery of the circulation", ''Symposium on Ibn al-Nafis'', Second International Conference on Islamic Medicine: Islamic Medical Organization, Kuwait ([[cf.]] [http://www.islamset.com/isc/nafis/drpaul.html The West denies Ibn Al Nafis's contribution to the discovery of the circulation], ''Encyclopedia of Islamic World'')</ref>


[[Marcello Malpighi]] was the first to observe and correctly describe capillaries when he discovered them in a frog's lung in 1661.<ref>{{cite book | title = Blood Vessels | author = John Cliff, Walter | year = 1976 | publisher = CUP Archives | page = 14}}</ref>
In the early 1980s, the demand for pesticides had fallen though production continued leading to buildup of stores of unused MIC.<ref name=Eckerman2004/><ref name=Kovel/>

===Work conditions===
Attempts to reduce expenses affected the factory’s employees and their conditions.

* Kurzman argues that “cuts... meant less stringent quality control and thus looser safety rules. A pipe leaked? Don’t replace it, employees said they were told... MIC workers needed more training? They could do with less. Promotions were halted, seriously affecting employee morale and driving some of the most skilled... elsewhere”.<ref name=Kurzman1987>Kurzman (1987).</ref>
* Workers were forced to use English manuals, despite the fact that only a few had a grasp of the language.<ref name=Chouhan/><ref name=Cassels><Cassels (1983)</ref>
* By 1984, only six of the original twelve operators were still working with MIC and the number of supervisory personnel was also cut in half. No maintenance supervisor was placed on the night shift and instrument readings were taken every two hours, rather than the previous and required one-hour readings.<ref name=Chouhan/><ref name=Kurzman1987/>
* Workers made complaints about the cuts through their union but were ignored. One employee was fired after going on a 15-day hunger strike. 70% of the plant’s employees were fined before the disaster for refusing to deviate from the proper safety regulations under pressure from management.<ref name=Chouhan/><ref name=Kurzman1987/>
* In addition, some observers, such as those writing in the Trade Environmental Database (TED) Case Studies as part of the Mandala Project from [[American University]], have pointed to “serious communication problems and management gaps between Union Carbide and its Indian operation”, characterised by “the parent companies [sic] hands-off approach to its overseas operation” and “cross-cultural barriers”.<ref name=TED>TED case 233 (1997)</ref>
* The personnel management policy led to an exodus of skilled personnel to better and safer jobs.<ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Eckerman2006>Eckerman (2006).</ref>

===Equipment and safety regulations===
* It emerged in 1998, during civil action suits in India, that, unlike Union Carbide plants in the USA, its Indian subsidiary plants were not prepared for problems. No action plans had been established to cope with incidents of this magnitude. This included not informing local authorities of the quantities or dangers of chemicals used and manufactured at Bhopal.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Kovel/>
* The MIC tank’s alarms had not worked for 4 years.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Lepowski>Lepowski (1994)</ref>
* There was only one manual back-up system, not the four-stage system used in the USA.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Lepowski/>
* The flare tower and the vent gas scrubber had been out of service for 5 months before the disaster. The gas scrubber therefore did not treat escaping gases with [[sodium hydroxide]] (caustic soda), which may have brought the concentration down to a safe level.<ref name=Lepowski/> Even if the scrubber had been working, according to Weir, investigations in the aftermath of the disaster discovered that the maximum pressure it could handle was only one-quarter of that which was present in the accident. Furthermore, the flare tower itself was improperly designed and could only hold one-quarter of the volume of gas that was leaked in 1984.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Weir>Weir (1987)</ref>
* To reduce energy costs, the refrigeration system, designed to inhibit the volatilization of MIC, had been left idle – the MIC was kept at 20 degrees Celsius, not the 4.5 degrees advised by the manual, and some of the coolant was being used elsewhere.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Lepowski/>
* The steam boiler, intended to clean the pipes, was out of action for unknown reasons.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Lepowski/>
* Slip-blind plates that would have prevented water from pipes being cleaned from leaking into the MIC tanks via faulty valves were not installed. Their installation had been omitted from the cleaning checklist.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref>
* Water sprays designed to “knock down” gas leaks were poorly designed – set to 13 metres and below, they could not spray high enough to reduce the concentration of escaping gas.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Lepowski/>
* The MIC tank had been malfunctioning for roughly a week. Other tanks had been used for that week, rather than repairing the broken one, which was left to “stew”. The build-up in temperature and pressure is believed to have affected the explosion and its intensity.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Lepowski/>
* Carbon-steel valves were used at the factory, despite the fact that they corrode when exposed to acid.<ref name=Kovel/> On the night of the disaster, a leaking carbon-steel valve was found, allowing water to enter the MIC tanks. The pipe was not repaired because it was believed it would take too much time and be too expensive.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Chouhan>Chouhan ''et al.'' (2004).</ref><ref name=Lepowski/>
* Themistocles D'Silva contends that the design of the MIC plant, following government guidelines, was "Indianized" by UCIL engineers to maximize the use of indigenous materials and products. It also dispensed with the use of sophisticated instrumentation as not appropriate for the Indian plant. Because of the unavailability of electronic parts in India, the Indian engineers preferred pneumatic instrumentation.<ref name=D>D'Silva (2006)</ref>

==Previous warnings and accidents==
A series of prior warnings and MIC-related accidents had been ignored:
* In 1976, the two trade unions reacted because of pollution within the plant.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Eckerman2006>Eckerman (2006).</ref>
* In 1981, a worker was splashed with phosgene. In panic he ripped off his mask, thus inhaling a large amount of phosgene gas; he died 72 hours later.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Eckerman2006>Eckerman (2006).</ref>
* In January 1982, there was a phosgene leak, when 24 workers were exposed and had to be admitted to hospital. None of the workers had been ordered to wear protective masks.
* In February 1982, an MIC leak affected 18 workers.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Eckerman2006>Eckerman (2006).</ref>
* In August 1982, a chemical engineer came into contact with liquid MIC, resulting in burns over 30 percent of his body.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Eckerman2006>Eckerman (2006).</ref>
* In October 1982, there was a leak of MIC, methylcarbaryl chloride, chloroform and hydrochloric acid. In attempting to stop the leak, the MIC supervisor suffered intensive chemical burns and two other workers were severely exposed to the gases.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Eckerman2006>Eckerman (2006).</ref>
* During 1983 and 1984, leaks of the following substances regularly took place in the MIC plant: MIC, chlorine, monomethylamine, phosgene, and carbon tetrachloride, sometimes in combination.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Eckerman2006>Eckerman (2006).</ref>
* Reports issued months before the incident by scientists within the Union Carbide corporation warned of the possibility of an accident almost identical to that which occurred in Bhopal. The reports were ignored and never reached senior staff.<ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Kovel/>
* Union Carbide was warned by American experts who visited the plant after 1981 of the potential of a “runaway reaction” in the MIC storage tank; local Indian authorities warned the company of problems on several occasions from 1979 onwards. Again, these warnings were not heeded.<ref name=Eckerman2004>Eckerman (2004).</ref><ref name=Kovel/>

==The leakage==

* In November 1984, most of the safety systems were not functioning. Many valves and lines were in poor condition. Tank 610 contained 43 tonnes MIC, much more than allowed according to safety rules.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* During the nights of 2-3 December, large amounts of water entered tank 610. A run-away reaction started, which was accelerated by contaminants, high temperatures and other factors. The reaction generated a major increase in the temperature of liquid inside the tank to over 200°C (400°F). The MIC holding tank then gave off a large volume of toxic gases, forcing the emergency release of pressure. The reaction was sped up by the presence of iron from corroding non-stainless steel pipelines.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* We know that workers cleaned pipelines with water. They were not told by the supervisor to add a slip-blind water isolation plate. Because of this, and of the bad maintenance, the workers consider it possible for water to enter the MIC tank.<ref name=Eckerman2001/><ref name=Eckerman2004/><ref name=Chouhan/>
* UCC maintains that a "disgruntled worker" deliberately connected a hose to a pressure gauge. However, this would hardly have been possible if the safety rules had been followed.<ref name=Eckerman2001/><ref name=Eckerman2004/><ref name=Kalelkar>Kalelkar (1988)</ref>

====Time line, summary====
At the plant<br />
* 21.00 Water cleaning of pipes start.<br />
* 22.00 Water enters 610. Reaction starts.<br />
* 22.30 Gases are coming out from the VGS-tower.<br />
* 00.30 The large siren sounds and is turned off.<br />
* 00.50 The siren is heard within the plant area. The workers escape.<br />
Outside<br />
* 22.30 First sensations felt. Suffocation, cough, eyes, vomiting.<br />
* 1.00 Police alerted. People escaped. UC-director denied a possible leak.<br />
* 2.00 The first people reached Hamidia hospital. Half blind, gasping for air, frothing at the mouth, vomiting.<br />
* 2.10 The alarm was heard outside the plant.<br />
* 4.00 The gases were reduced.<br />
* 6.00 The police's loudspeaker said: "Everything is normal".<br />
* Morning: Thousands of dead bodies and hundreds of dead cattle lying on the streets.

==Health effects==
Apart from MIC the gas cloud may have contained [[phosgene]], [[hydrogen cyanide]], [[carbon monoxide]], [[hydrogen chloride]], [[Nitrous oxide|nitrous oxides]], [[Methylamine|monomethyl amine]] (MMA) and [[carbon dioxide]], either produced in the storage tank or in the atmosphere<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref>. All these gases, except carbon dioxide, are acutely toxic at levels well below 500 [[Parts-per notation|ppm]].

The gas cloud, composed mainly of materials more dense than the surrounding air, stayed close to the ground and spread outwards through the surrounding community. The initial effects of gas exposure were coughing, vomiting, severe eye irritation and a feeling of suffocation. People awoken by these symptoms fled away from the plant. Those who ran inhaled more than those who had a vehicle. Due to their height, children and other people of lower stature inhaled relatively higher concentrations. Many people were trampled trying to escape<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref>.

Thousands of people had succumbed to gas exposure by the morning hours. There were mass funerals and mass cremations as well as bodies being disposed of in the Narmada river. 170,000 people were treated at hospitals and temporary dispensaries. 2,000 buffaloes, goats, and other animals had to be collected and buried. Within a few days, leaves on trees went yellow and fell off. Supplies including food became scarce due to safety fears by the suppliers. Fishing was prohibited as well which caused further supply shortages. <ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref>.

A total of 36 wards were marked by the authorities as being "gas affected", affecting a population of 520,000. In 1991, 3,928 deaths had been certified. Independent organizations recorded 8,000 dead the first days. Other estimations vary between 10,000 and 20,000. Another 100,000 to 200,000 people are estimated to have been injured.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004).</ref>

The majority of deaths and serious injuries were related to [[pulmonary edema]], but the gas caused a wide variety of other ailments. Signs and symptoms of methyl isocyanate exposure include coughing, [[dyspnea]], chest pain, [[lacrimation]], eyelid edema, and unconsciousness. These effects tend to progress over 24 to 72 hours following exposure to include acute lung injury, cardiac arrest, and death.

'''Long term health effects'''<br />
The quality of the epidemiological and clinical research varies. Reported and studied symptoms are eye problems, respiratory difficulties, immune and neurological disorders, cardiac failure secondary to lung injury, female reproductive difficulties, and birth defects among children born to affected women. Other symptoms and diseases are often ascribed to the gas exposure, but there is no good research supporting this.<ref name=Eckerman2001>Eckerman (2001)</ref><ref name=Eckerman2004>Eckerman (2004)</ref>. For a review of the research on the health effects of the Bhopal disaster (Dhara & Dhara, 2002), see http://www.ncbi.nlm.nih.gov/pubmed/12641179.

==Aftermath of the explosion==

* The doctors and the staff were completely taken by surprise as thousands and thousands of survivors entered the gates.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* Doctors and hospitals were not informed of proper treatment methods for MIC gas inhalation. They were told to simply give cough medicine and eye-drops to their patients.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* The gases immediately caused visible damage to the trees. Within a few days, all the leavsfelof.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* 2,000 bloated animal carcasses had to be taken care of.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* "Operation Faith" On december 16, the tanks 611 and 619 shoud be emptied of the remains of MIC. This led to a second mass evacuation from Bhopal.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* Complaints of a lack of information or misinformation were legion. Not even the medical doctor of the Bhopal plant had proper information about the properties of the gases. An Indian Government spokesman said that "Carbide is more interested in getting information from us than in helping our relief work."<ref name=Eckerman2001/><ref name=Eckerman2004/>
* Up to today, UCC has not released information about the possible composition of the cloud.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* Formal statements were issued that air, water, vegetation and foodstuffs were safe everywhere in the city. At the same time, television features informed people that poultry was unaffected, but warned people not to consume fish, etc.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* The survivors lost their economic standard, lost health and gained worries about the future. Much time was spent at hospitals and clinics. The expences fore medicines could sometimes esceed expenses on food. It was difficult for girls to get married.<ref name=Eckerman2001/><ref name=Eckerman2004/>
* Bhopal was invaded by American lawyers, radical groups and health personnel. Sometimes there was conflicts with the police.<ref name=Eckerman2001/><ref name=Eckerman2004/>

==Union Carbide’s defense==
Now owned by [[Dow Chemical Company]], Union Carbide denies allegations against it on its website dedicated to the tragedy. The corporation believes that the accident was the result of sabotage, stating that safety systems were in place and operative. It also stresses that it did all it could to alleviate human suffering following the disaster.<ref name=ucs>{{cite web |title = Statement of Union Carbide Corporation Regarding the Bhopal Tragedy |url = http://www.bhopal.com/ucs.htm |publisher = Bhopal Information Center, UCC}}</ref>

===Investigation into possible sabotage===
The company cites an investigation conducted by the engineering consulting firm [[Arthur D. Little]], which concluded that a single employee secretly and deliberately introduced a large amount of water into the MIC tank by removing a meter and connecting a water hose directly to the tank through the metering port.<ref>kalelkar</ref> Carbide claims such a large amount of water could not have found its way into the tank by accident, and safety systems were not designed to deal with intentional sabotage. UC says that the rest of the plant staff falsified numerous records to distance themselves from the incident, and that the Indian Government impeded its investigation and declined to prosecute the employee responsible, presumably because that would weaken its allegations of negligence against Union Carbide.{{Fact|date=August 2007}}

Union Carbide has never publicly named or identified the employee it claims sabotaged its Bhopal plant or attempted to prosecute. Nevertheless, on the company’s Bhopal Information Center website, Carbide claims that “the Indian authorities are well aware of the identity of the employee and the nature of the evidence against him”.<ref name=faq>{{cite web |url = http://www.bhopal.com/faq.htm |publisher = Bhopal Information Center, UCC |title = Frequently Asked Questions}}</ref>

===Safety and equipment issues===
The corporation denies the claim that the valves on the tank were malfunctioning, claiming that “documented evidence gathered after the incident showed that the valve close to the plant's water-washing operation was closed and leak-tight. Furthermore, process safety systems – in place and operational – would have prevented water from entering the tank by accident”. Carbide states that the safety concerns identified in 1982 were all allayed before 1984 and “none of them had anything to do with the incident”.<ref name = faq/>

The company admits that “the safety systems in place could not have prevented a chemical reaction of this magnitude from causing a leak”. According to Carbide, “in designing the plant's safety systems, a chemical reaction of this magnitude was not factored in” because “the tank's gas storage system was designed to automatically prevent such a large amount of water from being inadvertently introduced into the system” and “process safety systems – in place and operational – would have prevented water from entering the tank by accident”. Instead, they claim that “employee sabotage – not faulty design or operation – was the cause of the tragedy”.<ref name = faq/>

===Response===
The company stresses the “immediate action” taken after the disaster and their continued commitment to helping the victims. On December 4th, the day following the leak, Union Carbide sent material aid and several international medical experts to assist the medical facilities in Bhopal.<ref name = faq/>

Carbide put $2 million into the Indian Prime Minister’s immediate disaster relief fund on 11th December 1984.<ref name = faq/> The corporation established the Employees' Bhopal Relief Fund in February 1985, which raised more than $5 million for immediate relief.<ref name = chrono>{{cite web |publisher = Bhopal Information Center, UCC |title = Chronology |month = November | year = 2006 |url = http://www.bhopal.com/chrono.htm}}</ref>

In August 1987, Carbide made an additional $4.6 million in humanitarian interim relief available.<ref name = chrono/>

Union Carbide also undertook several steps to provide continuing aid to the victims of the Bhopal disaster after the court ruling, including:
* The sale of its 50.9 percent interest in UCIL in April 1992 and establishment of a charitable trust to contribute to the building of a local hospital. The sale was finalized in November 1994. The hospital was begun in October 1995 and was opened in 2001. The company provided a fund with around $90 million from sale of its UCIL stock. In 1991, the trust had amounted approximately $100 million. The hospital caters for the treatment of heart, lung and eye problems.<ref name=ucs/>
* Providing "a $2.2 million grant to Arizona State University to establish a vocational-technical center in Bhopal, which was constructed and opened, but was later closed and leveled by the government”.<ref name=irs>{{cite web |url = http://www.bhopal.com/irs.htm |publisher = Bhopal Information Center,UCC |title = Incident Response and Settlement}}</ref>
* Donating $5 million to the [[Indian Red Cross]].<ref name = irs/>
* Developing the [[Responsible Care]] system with other members of the chemical industry as a response to the Bhopal crisis, which is designed “to help prevent such an event in the future by improving community awareness, emergency preparedness and process safety standards”.<ref name = chrono/>

==Long-term fallout==
Legal action against Union Carbide has dominated the aftermath of the disaster. However, other issues have also continued to develop. These include the problems of ongoing contamination, criticisms of the clean-up operation undertaken by Union Carbide, and a 2004 hoax.

'''Time-line 1984-2004:''' See "Bhopal Gas Tragedy: Fact Sheet", Hindustan Times, Dec 3, 2004 <ref>{{cite journal |title = Bhopal Gas Tragedy: Fact Sheet |year = Dec 3, 2004|journal = [[Hindustan Times]] }}</ref>

===Legal action against Union Carbide===
Legal issues began affecting Union Carbide, the US and Indian governments, the local authorities in Bhopal and the victims of the disaster immediately after the catastrophe.

====Legal proceedings leading to the settlement====
On 14th December 1984, the Chairman and CEO of Union Carbide, [[Warren Anderson (chairman)|Warren Anderson]], addressed the US Congress, stressing the company’s “commitment to safety” and promising to ensure that a similar accident “cannot happen again”. However, the Indian Government passed the Bhopal Gas Leak Act in March 1985, allowing the Government of India to act as the legal representative for victims of the disaster,<ref name = chrono/> leading to the beginning of legal wrangling.

March 1986 saw Union Carbide propose a settlement figure, endorsed by plaintiffs’ US attorneys, of $350 million that would, according to the company, “generate a fund for Bhopal victims of between $500-600 million over 20 years”. In May, litigation was transferred from the US to Indian courts by US District Court Judge. Following an appeal of this decision, the US Court of Appeals affirmed the transfer, judging, in January 1987, that UCIL was a “separate entity, owned, managed and operated exclusively by Indian citizens in India”.<ref name = chrono/> The judge in the US, Judge Keenan, granted Carbide’s forum request, thus moving the case to India. This meant that, under US federal law, the company had to submit to Indian jurisdiction.

Litigation continued in India during 1988. The [[Supreme Court of India|Indian Supreme Court]] told both sides to come to an agreement and “start with a clean slate” in November 1988.<ref name = chrono/> Eventually, in an out-of-court settlement reached in 1989 , Union Carbide agreed to pay [[USD|US$]]470 million for damages caused in the Bhopal disaster, 15% of the original $3 billion claimed in the lawsuit.<ref name=Eckerman2004/> By the end of October 2003, according to the Bhopal Gas Tragedy Relief and Rehabilitation Department, compensation had been awarded to 554,895 people for injuries received and 15,310 survivors of those killed. The average amount to families of the dead was $2,200. <ref name=broughton>Broughton (2005)</ref>

Throughout 1990, the Indian Supreme Court heard appeals against the settlement from “activist petitions”. Nonetheless, in October 1991, the Supreme Court upheld the original $470 million, dismissing any other outstanding petitions that challenged the original decision. The decision set aside a “portion of settlement that quashed criminal prosecutions that were pending at the time of settlement”. The Court ordered the Indian government “to purchase, out of settlement fund, a group medical insurance policy to cover 100,000 persons who may later develop symptoms” and cover any shortfall in the settlement fund. It also “requests” that Carbide and its subsidiary “voluntarily” fund a hospital in Bhopal, at an estimated $17 million, to specifically treat victims of the Bhopal disaster. The company agreed to this.<ref name = chrono/> However, the International Campaign for Justice in Bhopal notes that the Court also reinstated criminal charges.

====Charges against Warren Anderson and others====
The Chairman and CEO of Union Carbide, [[Warren Anderson (chairman)|Warren Anderson]], had been arrested and released on bail by the Madhya Pradesh Police in Bhopal on December 7, 1984. This caused controversy as his trip to Bhopal was conditional on an initial promise by Indian authorities not to arrest him. Anderson has since refused to return to India.

Beginning in 1991, the local authorities from Bhopal charged Warren Anderson, who had retired in 1986, with manslaughter, a crime that carries a maximum penalty of 10 years in prison. Anderson has so far avoided an international arrest warrant and a US court summons. He was declared a fugitive from justice by the Chief Judicial Magistrate of Bhopal on February 1, 1992 for failing to appear at the court hearings in a culpable [[homicide]] case in which he was named the chief defendant. Orders were passed to the Government of India to press for an [[extradition]] from the [[United States]], with whom India had an extradition treaty in place. He went missing for several years, until he was discovered by [[Greenpeace]] “living a life of luxury in the Hamptons”.{{Fact|date=January 2008}} The Bhopal Medical Appeal believe that “neither the American nor the Indian government seem interested in disturbing him with an extradition”. Some allege that the Indian government has hesitated to put forth a strong case of extradition to the United States, fearing backlash from foreign investors who have become more important players in the Indian economy following [[liberalization]].{{Fact|date=January 2008}} A seemingly apathetic attitude from the US government, which has failed to pursue the case, has also led to strong protests in the past, most notably by Greenpeace. A plea by India's [[Central Bureau of Investigation]] to dilute the charges from culpable homicide to criminal negligence has since been dismissed by the Indian courts.

The [[Supreme Court of the United States|U.S. Supreme Court]] refused to hear appeal of the decision of the lower federal courts in October 1993, meaning that victims of the Bhopal disaster could not seek damages in a US court.<ref name = chrono/>

Meanwhile, very little of the money from the settlement reached with Union Carbide went to the survivors, and people in the area feel betrayed not only by Union Carbide (and chairman Warren Anderson), but also by their own politicians.<ref name = eckerman2001/><ref name= eckerman2004/> On the anniversary of the tragedy, effigies of Anderson and politicians are burnt.

In July 2004, the Indian Supreme Court ordered the Indian government to release any remaining settlement funds to victims. The deadline for this release was extended by the Indian Supreme Court In April 2005, giving the Indian government until 30th April 2006 after a request from the Welfare Commission for Bhopal Gas Victims. The fund is believed to amount to $500 million after earning interest “from money remaining after all claims had been paid”.<ref name = chrono/>

August 2006 saw the [[United States Court of Appeals for the Second Circuit|Second Circuit Court of Appeals]] in [[New York City]] upheld the dismissal of remaining claims in the case of ''Bano v. Union Carbide Corporation''. This move blocked plaintiffs’ motions for class certification and claims for property damages and remediation. In the view of Carbide, “the ruling reaffirms UCC’s long-held positions and finally puts to rest — both procedurally and substantively – the issues raised in the class action complaint first filed against Union Carbide in 1999 by Haseena Bi and several organizations representing the residents of Bhopal”. In September 2006, the Welfare Commission for Bhopal Gas Victims announced that all original compensation claims and revised petitions had been “cleared".<ref name = chrono/>

Criminal charges are proceeding against former Union Carbide India Limited employees including: Former UCIL Chairman Shri Keshub [[Mahindra]]; presently Chairman-cum managing Director Shri Vijay Gokhale; former Vice-President Functioning In charge, Shri Kishor Kamdar; former works manager Shri J. Mukund; and former Production manager A.P. Division, Shri S.P. Choudhury.

Federal class action litigation, Sahu v. Union Carbide et al.<ref>[http://www.studentsforbhopal.org/DowIsLiable.htm Dow's Liabilities<!-- Bot generated title -->]</ref>, is presently pending on appeal before the Second Circuit Court of Appeals in New York<ref>http://en.wikipedia.org/wiki/United_States_District_Court_for_the_Southern_District_of_New_York</ref>. The litigation seeks damages for personal injury, medical monitoring<ref>[http://www.thetruthaboutdow.org/article.php?id=945 The Truth About Dow : Govt handling of Bhopal: Blot on Indian Democracy, 224 Indian groups tell PM<!-- Bot generated title -->]</ref> and injunctive relief in the form of cleanup<ref>[http://www.thetruthaboutdow.org/article.php?id=920 The Truth About Dow : 25 years on, Govt wakes up to Bhopal waste but can’t find any one to clean it up<!-- Bot generated title -->]</ref> of the drinking water supplies<ref>[http://www.thetruthaboutdow.org/article.php?id=1038 The Truth About Dow : Decades Later, Toxic Sludge Torments Bhopal<!-- Bot generated title -->]</ref> for residential areas near the Bhopal plant<ref>[http://bhopal.net/bhopal.con/ Oops! You have reached Bhopal.con<!-- Bot generated title -->]</ref>. A related complaint seeking similar relief for property damage claimants is stayed pending the outcome of the Sahu appeal before the federal district court in the Southern District of New York.

==Changes in corporate identity==
===Sale of Union Carbide India Limited===
Union Carbide sold its Indian subsidiary, which had operated the Bhopal plant, to [[Eveready Industries|Eveready Industries India Limited]], in 1994.

===Merger of Union Carbide and Dow Chemical Company===
The [[Dow Chemical Company]] purchased Union Carbide in 2001 for $10.3 billion in stock and debt. Dow has publicly stated several times that the Union Carbide settlement payments have already fulfilled Dow's financial responsibility for the disaster.

Some Dow stockholders filed suits to stop the [[Mergers and acquisitions|merger]], noting the outstanding liabilities for the Bhopal disaster.<ref name=BMA>{{cite web |url = http://www.bhopal.org/whathappened.html |publisher = The Bhopal Medical Appeal |title = What Happened in Bhopal?}}</ref> The merger has gained criticism from the [[International Campaign for Justice in Bhopal]], as it is apparently “contrary to established merger law” in that “Dow denies any responsibility for Carbide’s Bhopal liabilities”. According to the Bhopal Medical Appeal, Carbide “remains liable for the environmental devastation” as environmental damage was not included in the 1989 settlement, despite ongoing contamination issues.<ref name=BMA/>

==Ongoing contamination from the accident==
Lack of political willpower has led to a stalemate on the issue of cleaning up the plant and its environs of hundreds of tonnes of toxic waste, which has been left untouched. [[Environmentalist]]s have warned that the waste is a potential minefield in the heart of the city, and the resulting [[contamination]] may lead to decades of slow poisoning, and diseases affecting the nervous system, liver and kidneys in humans. Studies have shown that the rates of [[cancer]] and other ailments are higher in the region since the event.{{Fact|date=June 2007}} Activists have demanded that Dow clean up this toxic waste, and have pressed the government of India to demand more money from Dow.

===Criticisms of Clean-up Operations===
Carbide states that “after the incident, UCIL began clean-up work at the site under the direction of Indian central and state government authorities”, which was continued after 1994 by the successor to UCIL, Eveready Industries, until 1998, when it was placed under the authority of the Madhya Pradesh Government.<ref name = chrono/> Critics of the clean-up undertaken by Carbide, such as the [[International Campaign for Justice in Bhopal]], claim that “several internal studies” by the corporation, which evidenced “severe contamination”, were not made public; the Indian authorities were also refused access. They believe that Union Carbide “continued directing operations” in Bhopal until “at least 1995” through Hayaran, the US trained site manager, even after the sale of its UCIL stock. The successor, Eveready Industries, abruptly relinquished the site lease to one department of the State Government while being supervised by another department on an extensive clean up programme. Environmental problems resulting from lack of a proper clean-up persist today<ref name=Eckerman2004/>. The Madhya Pradesh authorities have announced that they will “pursue both Dow and Eveready” to conduct the clean-up as joint tortfeasors.{{Fact|date=August 2007}}

The International Campaign view Carbide’s sale of UCIL in 1994 as a strategy “to escape the Indian courts, who threatened Carbide’s assets due to their non-appearance in the criminal case”. The successor, Eveready Industries India, Limited (EIIL), ended its 99 year lease in 1998 and turned over control of the site to the state government of the Madhya Pradesh.<ref name=ucs/> Currently, the Madhya Pradesh Government is trying to legally force Dow and EIIL to finance clean-up operations.

===Contamination from the site itself===
A large portion of the contamination in the site itself and the surrounding areas did not arise directly from the Bhopal disaster, but rather from the materials processed at the plant and the conditions under which those materials were processed. A report from [[Greenpeace]] details the extent and persistence of this contamination, which accounts for most of the heavy metal contamination.<ref name=stringer>Stringer et al (2002)</ref>

In 2002, an inquiry found a number of toxins, including [[Mercury (element)|mercury]], [[lead]], 1,3,5 [[trichlorobenzene]], [[dichloromethane]] and [[chloroform]], in nursing women’s breast milk. Well water and groundwater tests conducted in the surrounding areas in 1999 showed mercury levels to be at “20,000 and 6 million times” higher than expected levels; heavy metals and organochlorines were present in the soil. Chemicals that have been linked to various forms of cancer were also discovered, as well as [[trichloroethene]], known to impair fetal development, at 50 times above safety limits specified by the [[United States Environmental Protection Agency]] (EPA).<ref name=BMA/>

In an investigation broadcast on [[BBC Radio 5]] on November 14, 2004 <ref name = BBC>{{cite web |publisher = BBC Radio 5 |title = Bhopal faces risk of 'poisoning' |date = 2004-11-14 |url = http://search.bbc.co.uk/cgi-bin/search/results.pl?scope=all&tab=av&recipe=all&q=bhopal+faces+risk+of+%27poisoning%27&x=0&y=0}}</ref>, it was reported that the site is still contaminated with 'thousands' of metric tons of toxic chemicals, including [[benzene hexachloride]] and [[Mercury (element)|mercury]], held in open containers or loose on the ground. Some areas are reportedly so polluted that anyone entering the area for more than ten minutes is likely to lose consciousness. Rainfall causes run-off, polluting local wells and boreholes, and the results of tests undertaken on behalf of the [[BBC]] by accredited water analysis laboratories in the [[United Kingdom]] reveal pollution levels in borehole water 500 times the legal maximum in that country. Statistical surveys of local residents, with a control population in a similarly poor area away from the plant, are reported to reveal higher levels of various diseases around the plant.

==Additional Settlement Funds Hoax==
[[Image:Dow apologizes.jpg|right|thumb|Bichlbaum as Finisterra on BBC News]]

On December 3, 2004, the twentieth anniversary of the disaster, a man claiming to be a Dow representative named [[The Yes Men|Jude Finisterra]] was interviewed on the [[BBC]]. He claimed that the company had agreed to clean up the site and compensate those harmed in the incident. ([http://www.theyesmen.org/hijinks/dow/video.html video]) Immediately afterward, Dow's share price fell 4.2% in 23 minutes, for a loss of $2 billion in market value [http://www.democracynow.org/article.pl?sid=04/12/06/1453248]. Dow quickly issued a statement saying that they had no employee by that name &mdash; that he was an impostor, not affiliated with Dow, and that his claims were a hoax. BBC broadcast a correction and an apology. The statement was widely carried [http://www.zmag.org/content/showarticle.cfm?SectionID=66&ItemID=6795].

"Jude Finisterra" was actually [[Andy Bichlbaum]], a member of the activist prankster group [[The Yes Men]]. In 2002, The Yes Men issued [http://theyesmen.org/hijinks/dow/bhopalmemorialpress.html a phony press release] explaining why Dow refused to take responsibility for the disaster and started up a website, DowEthics.com, designed to look like the Dow website but give what they felt was a more accurate cast on the events. In 2004, a producer for BBC News emailed them through the website requesting an interview, which they gladly obliged [http://www.theyesmen.org/hijinks/dow/].

Taking credit for the prank in an interview on ''[[Democracy Now!]]'', Bichlbaum explains how his fake name was derived: "[[Saint Jude|Jude]] is the patron saint of impossible causes and Finisterra means the end of the Earth". He explained that he settled on this approach (taking responsibility) because it would show people precisely how Dow could help the situation as well as likely garnering major media attention in the US, which had largely ignored the disaster's anniversaries, when Dow attempted to correct the statement [http://www.democracynow.org/article.pl?sid=04/12/06/1453248].

After the original interview was revealed as a hoax, Bichlbaum appeared in a follow-up interview on the United Kingdom's Channel 4 news ([http://www.theyesmen.org/hijinks/dow/movies/Channel4news.mp4 video]). During the interview he was repeatedly asked if he had considered the emotions and reaction of the people of Bhopal when producing the hoax. According to the interviewer, "there were many people in tears" upon having learned of the hoax. Each time, Bichlbaum said that, in comparison, what distress he had caused the people was minimal to that for which Dow was responsible.


==See also==
==See also==
*[[Alveolar-capillary barrier]]
* [[Lake Nyos]], a natural disaster involving [[carbon dioxide]].
*[[Blood brain barrier]]
*[[Capillary action]]
*[[Hagen-Poiseuille equation]]


==Notes==
==References==
<!--See http://en.wikipedia.org/wiki/Wikipedia:Footnotes for an explanation of how to generate footnotes using the <ref(erences/)> tags-->
{{reflist}}
{{reflist}}

==References==
<!-- use cite templates -->
*{{cite journal |author =Broughton E |title = The Bhopal disaster and its aftermath: A review |year = 2005 |journal = Environmental Health |volume = 4 |issue = 1 |pages = 6 |doi = 10.1186/1476-069X-4-6 |pmid = 15882472 |format = [[http://www.ehjournal.net/content/4/1/6]]}} 10 May 2005

* {{cite book |last=Browning |first=Jackson |title=Union Carbide: Disaster at Bhopal |editor=Jack A. Gottschalk |series=Crisis Response: Inside Stories on Managing Image Under Siege |location=Detroit |year=1993 |url=http://www.bhopal.com/pdfs/browning.pdf |format=PDF |quote=Union Carbide's former vice-president of health, safety and environmental programs tells how he dealt with the catastrophe from a PR point of view.}}
* Cassels, J. (1993). ''The Uncertain Promise Of Law: Lessons From Bhopal.'' University Of Toronto Press.

*{{cite book |last=ChouhanTR and others |title=Bhopal: the Inside Story – Carbide Workers Speak Out on the World's Worst Industrial Disaster |year=1994, 2004 |publisher=The Apex Press |location=USA |isbn=1-891843-30-3}} India: Other India Press ISBN 81-85569-65-7 Main author Chouhan was an operator at the plant. Contains many technical details.
* {{cite web |url=http://webdrive.service.emory.edu/users/vdhara/www.BhopalPublications/Health%20Effects%20&%20Epidemiology/Health%20Effects%20Review%20articles/Health%20Effects%20Review%20AEH.pdf |title=The Union Carbide disaster in Bhopal: A review of health effects |last=Dhara |first=V. Ramana |coauthors=Dhara, Rosaline |work=Archives of Environmental Health |year=2002 |month=Sept/Oct |format=reprint |pages=391-404}}
* {{cite book |last=D'Silva |first=Themistocles |year=2006 |title=The Black Box of Bhopal: A Closer Look at the World's Deadliest Industrial Disaster |isbn=1-4120-8412-1}}Written by an employed at UCC.
* {{cite journal |author = D'Silva TDJ, Lopes A, Jones RL, Singhawangcha S, Chan JK |title = Studies of methyl isocyanate chemistry in the Bhopal incident |year = 1986 |journal = [[J. Org. Chem.]] |volume = 51 |issue = 20 |pages = 3781–3788 |doi = 10.1021/jo00370a007 }}

* {{cite web |url=http://www.dnsy.se/_upload/lfm/2006/bhopal%20gas%20disaster.pdf|title=Chemical Industry and Public Health - Bhopal as an example |last=Eckerman |first=Ingrid |year=2001|format=PDF}} Essay for MPH. A short overview, 57 pages, 82 references.
* {{cite book |last=Eckerman |first=Ingrid |title=The Bhopal Saga - Causes and Consequences of the World's Largest Industrial Disaster [http://www.eckerman.nu/default.cfm?page=The%20Bhopal%20Saga]|year=2004 |publisher=Universities Press |location=India |isbn=81-7371-515-7 }} All known facts 1960s - 2003, systematized and analysed. 283 pages, over 200 references.
* {{cite web |url=http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TGH-4GWC0T0-7&_coverDate=11%2F30%2F2005&_alid=467124665&_rdoc=1&_fmt=&_orig=search&_qd=1&_cdi=5255&_sort=d&view=c&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=617dd29a0310b5fc9d6deb0bf4b28153 |title=The Bhopal gas leak: Analyses of causes and consequences by three different models. |year=2005 |work=Journal of Loss Prevention in the process industry |last=Eckerman |first=Ingrid |pages=2005:18;213-217}}
* {{cite web |url=http://www.ttl.fi/NR/rdonlyres/AF130282-A0AB-4439-8E3C-AFF55CDEF59F/0/AsianPacific_Nwesletter22006.pdf |title=The Bhopal Disaster 1984 - working conditions and the role of the trade unions. |format=PDF |last=Eckerman |first=Ingrid |work=Asian Pacific Newsletter on occupational health and safety |year=2006 |pages=48-49}}
* {{cite book |title=A Cloud over Bhopal - Causes, Consequences and Constructive Solutions|year=1985 |author=de Grazia, Alfred|Metron Publications|isbn=0-940268-09-9 |url=http://www.grazian-archive.com/governing/bhopal/Publishers%20Note.html |format=HTML |quote=The first book on the Bhopal disaster, written on-site a few weeks after the accident.}}

*{{cite book |last=Hanna B, Morehouse W, Sarangi S |title=The Bhopal Reader. Remembering Twenty Years of the World's Worst Industrial Disaster |year=2005 |publisher=The Apex Press |location=USA |isbn=1-891843-32-X USA, 81-85569-70-3 India}} Reprinting and annotating landmark writing from across the years.
* {{cite journal |journal=Isis |year=2007 |volume=98 |pages=344–350 |title=Bhopal’s Trials of Knowledge and Ignorance |first=Sheila |last=Jasanoff |url=http://www.journals.uchicago.edu/doi/full/10.1086/518194 |doi=10.1086/518194 <!--Retrieved from URL by DOI bot-->}}

* {{cite book |author=Kalelkar AS, Little AD. |year=1998 |title=Investigation of Large-magnitude incidents: Bhopal as a Case Study.}} London: The Institution of Chemical Engineers Conference on Preventing Major Chemical Accidents

* Kurzman, D. (1987). ''A Killing Wind: Inside Union Carbide and the Bhopal Catastrophe''. New York: McGraw-Hill.
*{{cite book |last=Kovel |first=J |year=2002 |ISBN= |title=The Enemy of Nature: The End of Capitalism or the End of the World? |Publisher=London: Zed Books}}
* {{cite book |last=Lapierre |first=Dominique |coauthors=Moro, Javier |year=2001 |isbn=0-446-53088-3 |title=Five Minutes Past Midnight in Bhopal}} A novel, based on facts, that describes the development from the 1960s to the disaster itself. Very thrilling.
* Lepowski, W. "Ten Years Later: Bhopal". Chemical and Engineering News, 19 December 1994.
* {{cite web |url=http://www.ttl.fi/NR/rdonlyres/AF130282-A0AB-4439-8E3C-AFF55CDEF59F/0/AsianPacific_Nwesletter22006.pdf |title=Bhopal Revisited - the tragedy of lessons ignored |format=PDF |last=Rice |first=Annie |coauthors=ILO |work=Asian Pacific Newsletter on occupational health and safety |year=2006|pages=46-47}}

*{{cite book |last=Singh |first=Moti|title=Unfolding the Betrayal of Bhopal Gas Tragedy |year=2008 |publisher=B.R. Publishing Corporation |location=Delhi, India |isbn=8176466220}} The chief coordinator of rescue operations at the district level writes rather critically on how the administration and bureaucracy functioned after the disaster.

* {{cite web|url=http://www.greenpeace.org/raw/content/international/press/reports/chemical-stockpiles-at-union-c.pdf|author=Stringer R, Labunska I, Brigden K, Santillo D.|year=2002|title=Chemical Stockpiles at Union Carbide India Limited in Bhopal: An investigation|publisher=Greenpeace Research Laboratories|Technical Note 12/2002}}

* Weir, D (1987). ''The Bhopal Syndrome: Pesticides, Environment and Health.'' San Francisco: Sierra Club Books
====Reports====
* {{cite web |url=http://www.american.edu/ted/bhopal.htm |title=Bhopal Disaster |publisher=Trade Environmental Database. TED case studies no. 233, American University, Washington (1 Nov 1997)}}
* {{cite web|url=http://bioterrorism.slu.edu/pulmonary/quick/methyliso.pdf |title=Chemical Terrorism Fact Sheet: Methyl Isocyanate.}} CSB&EI, Saint Louis University School of Public Health, USA
* {{cite book |title=Health Effects of the Toxic Gas Leak from the Union Carbide Methyl Isocyanate Plant in Bhopal. Technical report on Population Based Long Term, Epidemiological Studies (1985-1994)}} Bhopal Gas Disaster Research Centre, Gandhi Medical College, Bhopal (2003?)

* {{cite web |url=http://webdrive.service.emory.edu/users/vdhara/www.BhopalPublications |title=Health and Epidemiology Papers About the Bhopal Disaster}}

* {{cite web |url=http://www.bhopal.net/oldsite/unproventechnology.html |title=Unproven technology |publisher=Bhopal.net (14 Nov 2002)}}


==External links==
==External links==
{{wiktionary}}
* [http://www.cipa-apex.org/books/bhopal/ The Bhopal Library] The Apex Press, New York
* {{BUHistology|00903loa}}
* [http://www.bhopal.net/ International Campaign For Justice in Bhopal]
* [http://www.bhopal.org/ Bhopal Medical Appeal and Sambhavna Trust Clinic]
* [http://www.studentsforbhopal.org/ Students for Bhopal]
* [http://www.bhopal.com/ Bhopal Information Center (UCC:s Bhopal Web Site)]
* [http://web.amnesty.org/pages/ec-bhopal-eng Clouds of Injustice: Bhopal disaster 20 Years on] Amnesty International report (link to 100 page pdf file)
* [http://www.indrasinha.com/bhanna-777.html/ Animal's People] A fictionalized story of a Bhopal survivors that recreates present day Bhopal for the reader
* The official website of [http://www.mp.gov.in/bgtrrdmp/ Bhopal Gas Tragedy Relief & Rehabilitation Department,] Government of Madhya Pradesh
* [http://bhopal.strategicvideo.net/ Twenty Years Without Justice: The Bhopal Chemical Disaster] International Campaign for Justice for Bhopal video
* [http://www.dowethics.com/ Fake Dow website] by [[The Yes Men]]
* [http://www.bhopal.fm Bhopal related community website broadcasting music and video]
* {{cite web |publisher = [[BBC News]] |url = http://news.bbc.co.uk/2/hi/programmes/bhopal/default.stm |title = One Night in Bhopal}}
* [http://webdrive.service.emory.edu/users/vdhara/www.BhopalPublications Health and Epidemiology Papers About the Bhopal Disaster] - mostly from peer-reviewed journals
* [http://www.netphotograph.com/pablo/bhopal_photos.html Pablo Bartholomew] The most welknown photoes from December 1984
* [http://www.commonlanguageproject.net/photos/BhopalSlideshowFinal.htm The Ghosts of Bhopal] slideshow from the Common Language Project
* [http://www.worldpressphoto.nl/index.php?option=com_photogallery&task=view&id=180&Itemid=115&bandwidth=high World Press Photo of the Year for 1984] - Child killed by the poisonous gas leak in the Union Carbide chemical plant disaster.
* [http://www.youtube.com/watch?v=Xz-BfXLjQ9c&feature=related It happened in Bhopal part 1] Reportage 27 Aug 2007 (Youtube)
* [http://www.youtube.com/watch?v=GgpJKSbEINQ&feature=related It happened in Bhopal part 2] Reportage 27 Aug 2007 (Youtube)
* [http://www.irastimes.org/bhopal_gas_tragedy.htm Bhopal Gas Tragedy] A railway officer described how he received victims coming by train. (2002)


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[[Category:Bhopal disaster| ]]
[[Category:Cardiovascular system]]
[[Category:Environmental disasters]]
[[Category:Industrial disasters]]
[[Category:1984 disasters]]


[[ar:شعيرة دموية]]
[[bn:ভোপালের বিপর্যয়]]
[[bs:Kapilari]]
[[cs:Bhópálská katastrofa]]
[[cy:Trychineb Bhopal]]
[[da:Kapillær]]
[[de:Katastrophe von Bhopal]]
[[de:Kapillare]]
[[et:Bhopali avarii]]
[[es:Capilar sanguíneo]]
[[fa:مویرگ]]
[[es:Desastre de Bhopal]]
[[fr:Catastrophe de Bhopal]]
[[fr:Capillaire sanguin]]
[[id:Tragedi Bhopal]]
[[ko:모세혈관]]
[[is:Háræð]]
[[it:Disastro di Bhopal]]
[[it:Capillare]]
[[he:אסון בופאל]]
[[hu:Bhopali katasztrófa]]
[[he:נים (כלי דם)]]
[[lv:Kapilāri]]
[[mr:भोपाळ वायुदुर्घटना]]
[[nl:Giframp Bhopal]]
[[lt:Kapiliaras]]
[[nl:Haarvat]]
[[ja:ボパール化学工場事故]]
[[ja:毛細血管]]
[[pl:Katastrofa w Bhopalu]]
[[no:Kapillar]]
[[ru:Бхопальская катастрофа]]
[[nds:Kapillar]]
[[fi:Bhopalin onnettomuus]]
[[tr:Bhopal felaketi]]
[[pl:Naczynie włosowate]]
[[pt:Capilar sanguíneo]]
[[uk:Трагедія Бхопала]]
[[zh:博帕爾事件]]
[[ru:Капилляр]]
[[sq:Kapilare]]
[[simple:Capillary]]
[[sk:Vlásočnica]]
[[sr:Капилар]]
[[fi:Hiussuoni]]
[[sv:Kapillär]]
[[tr:Kılcal damar]]
[[uk:Капіляр (біологія)]]
[[zh:微血管]]

Revision as of 22:15, 12 October 2008

Blood flows from the heart to arteries, which narrow into arterioles, and then narrow further still into capillaries. After the tissue has been perfused, capillaries widen to become venules and then widen more to become veins, which return blood to the heart.

Capillaries are the smallest of a body's blood vessels, measuring 5-10 μm in diameter, which connect arterioles and venules, and enable the interchange of water, oxygen, carbon dioxide, and many other nutrient and waste chemical substances between blood and surrounding tissues.[1]

Anatomy

Blood flows from the heart to arteries, which branch and narrow into arterioles, and then branch further still into capillaries. After the tissue has been perfused, capillaries join and widen to become venules and then widen more to become veins, which return blood to the heart.

The "capillary bed" is the network of capillaries supplying an organ. The more metabolically active the cells, the more capillaries it will require to supply nutrients and carry away waste products.

Metarterioles provide direct communication between arterioles and venules and are important in bypassing the bloodflow through the capillaries. True capillaries branch mainly from metarterioles and provide exchange between cells and the circulation. The internal diameter of 8 μm forces the red blood cells to partially fold into bullet-like shapes in order to by pass them in single file.

Precapillary sphincters are rings of smooth muscles at the origin of true capillaries that regulate blood flow into true capillaries and thus control blood flow through a tissue.

Types

Capillaries come in three types:

  • Continuous - Continuous capillaries have a sealed endothelium and only allow small molecules, like water and ions to diffuse. Continuous capillaries can be further divided into two subtypes:
  1. Those with numerous transport vesicles and tight junctions that are primarily found in skeletal muscles, lungs, gonads, and skin.
  2. Those with few vesicles and tight junctions that are primarily found in the central nervous system.
  • Fenestrated - Fenestrated capillaries (derived from "fenestra," the Latin word for "window") have pores in the the endothelial cells (60-80 nm in diameter) that are spanned by a diaphragm of radially oriented fibrils and allow small molecules [2][3] and limited amounts of protein to diffuse. In the renal glomerulus there are larger fenestrae which have no diaphragms. Both types of fenestrated blood vessels have continuous basal lamina and are primarily located in the endocrine glands, intestines, pancreas and glomeruli of kidney.
  • Sinusoidal - Sinusoidal or discontinuous capillaries are special fenestrated capillaries that have larger openings (30-40 μm in diameter) in the epithelium to allow red blood cells and serum proteins to enter, a process that is aided by a discontinuous basal lamina. These capillaries lack pinocytotic vesicles and gaps may be present in cell junctions permitting leakage between endothelial cells. Sinusoid blood vessels are primarily located in the liver, spleen, bone marrow, lymph nodes, and adrenal cortex.

Physiology

The capillary wall is a one-layer endothelium so thin that gas and molecules such as oxygen, water, proteins and lipids can pass through them driven by osmotic and hydrostatic gradients. Waste products such as carbon dioxide and urea can diffuse back into the blood to be carried away for removal from the body. The physics of this exhange is explained by the Starling equation.

The capillary bed usually carries no more than 25% of the amount of blood it could contain, although this amount can be increased through auto regulation by inducing relaxation of smooth muscle in the arterioles that lead to the capillary bed as well as constriction of the metarterioles.

The capillaries do not possess this smooth muscle in their own wall, and so any change in their diameter is passive. Any signaling molecules they release (such as endothelin for constriction and nitric oxide for dilation) act on the smooth muscle cells in the walls of nearby, larger vessels, e.g. arterioles.

Capillary permeability can be increased by the release of certain cytokines, such as in an immune response.

Starling equation is a mathmatical model for fluid movement across capillaries: Jv=Kf[(Pc-Pi)-(pc-pi)] where: Jv = fluid movement (ml/min) Kf = hydraulic conductance (ml/min. mmHg) Pc = Capillary hydrostatic pressure Pi = Interstetial hyrdostatic pressure pc = capillary oncotic pressure pi = interstestial oncotic pressure.

Immune response

In an immune response, the endothelial cells of the capillary will upregulate receptor molecules, thus it signals the need for an immune response by the site of infection and aids extravasion of these cells into the tissue.

History

Ibn al-Nafis theorized a "premonition of the capillary circulation in his assertion that the pulmonary vein receives what comes out of the pulmonary artery, this being the reason for the existence of perceptible passages between the two."[4]

Marcello Malpighi was the first to observe and correctly describe capillaries when he discovered them in a frog's lung in 1661.[5]

See also

References

  1. ^ Maton, Anthea (1993). Human Biology and Health. Englewood Cliffs, New Jersey: Prentice Hall. ISBN 0-13-981176-1. {{cite book}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)
  2. ^ Histology image: 22401lba – Histology Learning System at Boston University
  3. ^ Pavelka, Margit; Jürgen Roth (2005). Functional Ultrastructure: An Atlas of Tissue Biology and Pathology. Springer. p. 232.{{cite book}}: CS1 maint: multiple names: authors list (link)
  4. ^ Dr. Paul Ghalioungui (1982), "The West denies Ibn Al Nafis's contribution to the discovery of the circulation", Symposium on Ibn al-Nafis, Second International Conference on Islamic Medicine: Islamic Medical Organization, Kuwait (cf. The West denies Ibn Al Nafis's contribution to the discovery of the circulation, Encyclopedia of Islamic World)
  5. ^ John Cliff, Walter (1976). Blood Vessels. CUP Archives. p. 14.

External links

Look up capillary in Wiktionary, the free dictionary.
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