Methane in water of Gulf 'astonishingly high'-US scientist

[Pathfinder]

Methane in Gulf 'astonishingly high'-US scientist

By Julie Steenhuysen


CHICAGO June 22 (Reuters) - As much as 1 million times the normal level of methane gas has been found in some regions near the Gulf of Mexico oil spill, enough to potentially deplete oxygen and create a dead zone, U.S. scientists said on Tuesday.

Texas A&M University oceanography professor John Kessler, just back from a 10-day research expedition near the BP Plc (BP.L) oil spill in the gulf, says methane gas levels in some areas are "astonishingly high."

Kessler's crew took measurements of both surface and deep water within a 5-mile (8 kilometer) radius of BP's broken wellhead.

"There is an incredible amount of methane in there," Kessler told reporters in a telephone briefing.

In some areas, the crew of 12 scientists found concentrations that were 100,000 times higher than normal.

"We saw them approach a million times above background concentrations" in some areas, Kessler said.


more...

http://in.reuters.com/article/idUSN2221822720100622

[LaMenchos]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

Potential effects of gas hydrate on human welfare. [FREE COMPLETE ARTICLE]
Kvenvolden KA.[/B]
U.S. Geological Survey, 345 Middlefield Road, MS999, Menlo Park, CA 94025, USA. kk@octopus.wr.usgs.gov

Proc Natl Acad Sci U S A. 1999 Mar 30;96(7):3420-6.

Abstract
For almost 30 years. serious interest has been directed toward natural gas hydrate, a crystalline solid composed of water and methane, as a potential (i) energy resource, (ii) factor in global climate change, and (iii) submarine geohazard. Although each of these issues can affect human welfare, only (iii) is considered to be of immediate importance. Assessments of gas hydrate as an energy resource have often been overly optimistic, based in part on its very high methane content and on its worldwide occurrence in continental margins. Although these attributes are attractive, geologic settings, reservoir properties, and phase-equilibria considerations diminish the energy resource potential of natural gas hydrate. The possible role of gas hydrate in global climate change has been often overstated. Although methane is a "greenhouse" gas in the atmosphere, much methane from dissociated gas hydrate may never reach the atmosphere, but rather may be converted to carbon dioxide and sequestered by the hydrosphere/biosphere before reaching the atmosphere. Thus, methane from gas hydrate may have little opportunity to affect global climate change. However, submarine geohazards (such as sediment instabilities and slope failures on local and regional scales, leading to debris flows, slumps, slides, and possible tsunamis) caused by gas-hydrate dissociation are of immediate and increasing importance as humankind moves to exploit seabed resources in ever-deepening waters of coastal oceans. The vulnerability of gas hydrate to temperature and sea level changes enhances the instability of deep-water oceanic sediments, and thus human activities and installations in this setting can be affected.

...


PMCID: PMC34283 Free PMC Article
PMID: 10097052 [PubMed - indexed for MEDLINE]

[LaMenchos]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

This is an area in which I have no expertise. I do not know what amounts of methane are considered "large" or significant in terms of effects on humans, effects on the climate.

Does anyone have such information?

[sharon sanders]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

Methane is CH4.

:...A fuel - air mixture can ignite without the introduction of an ignition source. The minimum auto-ignition temperature is the lowest temperature at which the fuel vapours spontaneously ignite. Hydrocarbons that have been heated can ignite if they are exposed to air. The figure below shows the auto-ignition temperatures of hydrocarbons at atmospheric pressure.

Minimum Auto-ignition Temperature of Hydrocarbons [14]

Methane has the highest auto-ignition temperature. As the number of carbon atoms in the hydrocarbon increases, the auto-ignition temperature decreases. In other words, heavier hydrocarbons tend to auto-ignite before lighter hydrocarbons. Increased pressures can also reduce the auto-ignition temperature."

http://www.firesandexplosions.ca/hazards/hydrocarbon_fuels.php#flammability_limits

[Ronan Kelly]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

METHANE
BACKGROUND INFORMATION
PHYSICAL AND CHEMICAL PROPERTIES
Structural formula:
CH4

Molecular weight:
16.04

CAS number:
74?82?8

Boiling point:
−161.49?C

Freezing point:
−182.48?C

Vapor pressure:
40 mm Hg (−86.3?C)

Flash point:
−187.78?C

Flammability limits:
5.3?14%

Physical state:
A colorless, odorless, flammable gas and the major component of natural gas. It forms explosive mixtures with air and is moderately soluble in water.


SUMMARY OF TOXICITY INFORMATION
Little information is available on the toxicity of methane. It appears that toxic effects of methane, considered biologically inert, are related to the oxygen deprivation that occurs when the simple alkane is present in air at a high concentration. Hunter (1978) stated that miners evacuate coal pits when the methane concentration in air reaches 2.5% by volume; it is not clear whether evacuation is prompted by the threat of a health hazard or by the danger of explosion.

Kamens and Stern (1973) referred to a literature survey that indicated that methane is biologically inert and that exposure to methane at 10,000 ppm had no toxic effect; conditions of exposure and identification of the test animal were not given, but a U.S. Department of Health, Education and Welfare report was cited (1970).

A report by Pennington and Fuerst (1971) supported the biologic inertness of methane. Suspensions of rabbit erythrocytes were exposed for 18 h to methane by bubbling through the suspensions at 150 ml/min. Such exposure had little or no effect on the color or morphology of the red cells, on the pH of the medium, on the ATP content of the cells, or on the electrophoretic pattern and UV/VIS absorption spectra of the hemoglobin obtained from exposed cells.

Forney and Harger (1972), however, offered evidence that methane has mild anesthetic properties that cannot be explained by oxygen deficiency alone, although such deficiency does seem to be the most important factor. Two of six mice exposed to 70% methane in air died in 18 min, whereas mice exposed to 70% nitrogen in air developed only ataxia. Animals exposed to 50?90% methane in oxygen showed mild depression and a marked decrease in locomotion, but no ataxia. Thus, the toxic effect of methane is much greater than that of nitrogen when available oxygen is low, but methane has little effect when oxygen is readily available. It seems that the toxicity of methane should be discussed not alone, but rather with respect to the partial pressure of oxygen in the atmosphere in question.

Carpenter (1954) demonstrated an anesthetic effect of methane under hyperbaric conditions in mice; 50% of a group of mice exposed to 2.9 atm of methane did not develop convulsions in response to electroshock treatment.

EXPLOSION HAZARD OF METHANE
Methane forms explosive mixtures with air and the loudest explosions occur when one volume of methane is mixed with 10 volumes of air (or 2 volumes of oxygen) (Windholz et al., 1976). Air containing less than 5.5% methane no longer explodes. The CRC Handbook of Chemistry and Physics (Weast, 1978?1979) gave the limits of flammability of methane as 5% and 15% by volume in air at room temperature.

INHALATION EXPOSURE LIMITS
ACGIH (1982) lists methane in its category of simple asphyxiants. This is described as being gases and vapors, which when present in high concentrations in air, act as simple asphyxiants without other significant physiologic effects. TLVs are not recommended because the limiting factor is the available oxygen.

COMMITTEE RECOMMENDATIONS
EXPOSURE LIMITS
In 1966, the Committee on Toxicology set an EEL and a CEL for methane:

24-h EEL:
5,000 ppm

90-d CEL:
5,000 ppm


No rationale accompanied these limits.

It is obvious that an exposure limit that presents an explosion hazard cannot be recommended, even if it is well below a concentration that would produce toxicity; thus, exposure limits should not exceed 5% by volume in air.

Animals exposed to methane at 10,000 ppm showed no toxic efects; an uncertainty factor of 2 is suggested to derive an EEL?5,000 ppm. There is no evidence that duration of exposure is important in methane toxicity. Therefore, no change in the previously recommended exposure limits seems necessary.
REFERENCES
American Conference of Governmental Industrial Hygienists. 1982. Threshold Limit Values for Chemical Substances and Physical Agents in the Work Environment with Intended Changes for 1982. Cincinnati, OH.: ACGIH. [93 p.]



Carpenter, F.G. 1954. Anesthetic action of inert and unreactive gases on intact animals and isolated tissues. Amer. J. Physiol. 178:505?509.



Forney, R.B., Jr., and Harger, R.N. 1972. Reaction of mice from acute exposure to various concentrations of methane, ethane, propane and butane in air, or in oxygen. Edinburgh, Scotland: Sixth International Meeting of Forensic Sciences. [12 p.]



Hunter, D. 1978. The Diseases of Occupations. 6th ed. London: Hodder and Stoughton. p. 630?632.



Kamens, R.M. and Stern, A.C. 1973. Methane in air quality and automobile exhaust emission standards. J. Air Pollution Control Assoc. 23:592?596.



Pennington, K., and Fuerst, R. 1971. Biochemical and morphological effects of various gases on rabbit erythrocytes. Arch. Environ. Health 22:476?481.



U.S. Dept. Health, Education and Welfare. 1970. Air Quality Criteria for Hydrocarbon. National Air Pollution Control Admin. Publ. No. AP-64. Washington, DC: U.S. Government Printing Office, p. 7?1, 7?3.



Weast, R.C. ed. 1978?1979. CRC Handbook of Chemistry and Physics. 59th ed. West Palm Beach, FL: CRC Press, Inc.

Windholz, M., Budavari, S., Stroumtsos, L.Y., and Fertig, M.N. 1976. The Merck Index: An Encyclopedia of Chemicals and Drugs. 9th ed. Rahway, NJ: Merck and Co. p. 776.

http://www.nap.edu/openbook.php?record_id=689&page=95

[Anne]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

same :

http://www.ccohs.ca/oshanswers/chemicals/chem_profiles/methane/basic_met.html

[sharon sanders]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

People need to stay away from the methane areas in the Gulf.


Forensic Sci Int. 1998 Aug 31;96(1):47-59.
Asphyxia due to oxygen deficiency by gaseous substances.

Watanabe T, Morita M.
Department of Legal Medicine, School of Medicine, Sapporo Medical University, School of Medicine, Japan.
Abstract

The determination of the cause of death in asphyxiation gas cases is very difficult because of the variation in circumstances surrounding such deaths. To clarify the cause of death and to identify the factors involved in asphyxia, the symptoms during asphyxia, the concentration of gases at the respiratory arrest, the time to death and the concentration of the gaseous substances in the tissues were studied using rats and six gases.



Three inhalations were used: (1) rapid asphyxia (2-3 min) in the exposure chamber in which the oxygen was depleted completely, (2) prolonged asphyxia (20-25 min) by gradually depleted oxygen, and (3) asphyxia by the inhalation of gases saturated with a critical gas concentration, maintaining the O2 at 20% (60 min).



In the rapid asphyxia groups, respiratory arrest occurred within 30 to 40 s, followed by cardiac arrest 2 or 3 min thereafter. Severe convulsions were observed only with the use of nitrogen. In the prolonged asphyxia groups, respiratory arrest occurred at the concentration of 4-5% O2 with non-toxic gases (N2, CH4, N2O, and propane). The toxic gases CO2 and Freon-22 produced respiratory arrest at the concentration of 6.6-8.0% O2 (60-67% CO2) and 13-14% of O2 (30-35% Freon-22), respectively. Variations in the concentrations of the gases among the tissues was observed according to the type of asphyxia, type of gas and the duration of exposure. The concentration of the fat-soluble gases in the adipose tissue showed marked variation according to the duration of the exposure.



The distribution pattern of methane was different from those of the other gases, in which the variation of concentrations among the tissues except lung were little in both rapid and prolonged asphyxia. These phenomena were considered to be attributable to the solubility of the gaseous substances in blood and tissues. Atrophy in the alveoli was observed after the rapid asphyxia with CO2 and N2O. Local hemorrhaging in the lungs was also observed, especially in CO2 asphyxia. The risks of oxygen-depletion asphyxia are the rapid reaction of loss of consciousness and respiratory and cardiac arrest. This paper presents valuable findings for the diagnosis of the cause of death and estimating the situation of the accident in cases of asphyxia.

http://www.ncbi.nlm.nih.gov/pubmed/9800365

[sharon sanders]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

Apparently a fairly low level of methane gas can cause death in an enclosed area.

Am J Forensic Med Pathol. 1992 Mar;13(1):69-71.
Death scene gas analysis in suspected methane asphyxia.

Byard RW, Wilson GW.
Department of Histopathology, Adelaide Children's Hospital, Australia.
Comment in:

• Am J Forensic Med Pathol. 1993 Dec;14(4):350-1.

Abstract

Two cases of methane asphyxia occurring in two boys (age 11 and 12 years) who were found at the bottom of a 37-ft (11.1-m)-deep sewer shaft are described. Attempted resuscitation of the first patient was unsuccessful and achieved only temporary stabilization of the second, who died 48 h after his discovery. Autopsies revealed relatively minor multifocal traumatic injuries, with evidence of hypoxic-ischemic encephalopathy in the patient who survived for 2 days. Subsequent analysis of gas in the shaft revealed 21% oxygen at the surface, 14.3% at a depth of 5 ft (1.5 m), and only 4.8% at depths of 10 ft (3 m) and below. Other gases detected at the lower levels were methane, nitrogen, and carbon dioxide (4.3%). These cases demonstrate the value of atmospheric gas analysis in cases of possible methane asphyxia in confirming the presence of methane and in demonstrating levels of oxygen below that necessary to support life.


http://www.ncbi.nlm.nih.gov/pubmed/1344637

[Ronan Kelly]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

It would seem that the Oxygen level is an important co-factor here. I'm not an expert in this, but I suspect that an O2 level of 5% in open space is unlikely.

[Ronan Kelly]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

The big problem of methane in a marine environment is not its toxicity, rather;

What?s the problem with methane? The microbes that feed off it. It can create ?methane seep ecosystems??shallow food chains that eat crude oil and dissolved methane and in the process consume all available oxygen, leaving nothing for other marine life forms. Bacteria eat the methane and ?ice worms? (so-called because they live around ice-like methane hydrate) eat bacteria, but nothing else eats these worms. This creates a ?dead zone.?

http://blogs.discovermagazine.com/80beats/2010/06/24/will-methane-gas-in-gulf-waters-create-a-massive-dead-zone/

So in short [an abundance of creatures that use] methane for food and oxygen to ?breathe? will create areas where only bacteria and a few other non-life sustaining organisms can live. All others die.

http://www.sfgate.com/cgi-bin/blogs/ybenjamin/detail??blogid=150&entry_id=66419

[Shannon Bennett]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

What are we to do? How do we clean up this mess? What are the consequences if we do nothing? Or little? What happens if we just let nature run its course? How long willit take to mitigate the disaster?

I have read of science experiments where methane catches fire in air because of the presence of either phosphine PH<SUB>3</SUB> or diphosphine P<SUB>2</SUB>H<SUB>4. </SUB>Both of those gases are spontaneously flammable in air. That research was done to explain such phenomena as will-o-the-wisps and corpse candles. Many have seen them but up to now they remain unexplained by the scientific community. A more plausible catastrophe might come from a spark igniting a large portion of the slick. Or as already tried a deliberate burn.

I remember seeing films of WWII in which the ocean appeared to be on fire. What would that amount of burning oil do to the environment? The soot alone would enhance rainfall downwind. It would also darken skies. What about oxygen depletion, super-heated air, as well as the possibility of burning any mammals caught in the mess?

But if we do nothing than how many species will die? Will it send any into oblivion forever? Where do you take the stuff once it has been collected? Can you burn it? And if you did what would be the consequences? What is happening to local sewage plants when oiled birds and slickers have been cleaned? And to top it all off the gusher is still gushing and we still have no real solutions.

[sharon sanders]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

It would seem that the Oxygen level is an important co-factor here. I'm not an expert in this, but I suspect that an O2 level of 5&#37; in open space is unlikely.

I agree. I am concerned for the human crews that are cleaning up, in and out, of the water.

"'We saw them approach a million times above background concentrations in some areas,' Kessler said."

It would appear that the marine life would be gravely affected in these areas.

[Ronan Kelly]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

Here's a link to a study from 2005 on models of deep spills - predicting underwater plumes and dissolved CH4

http://www.mms.gov/tarprojects/377/Adams&#37;20Review%204.pdf

....

7. Conclusions
The following has been learned from the six activities described above, in reference to the fate of oil spilled in the deep ocean.
1. Jets of oil and gas (if present) will break up into droplets and bubbles, respectively. The mechanism of breakup depends on the source conditions, and could result in a wide range of diameters ranging from less than one mm to the approximate size of the discharge opening, or the maximum stable diameter (whichever is smaller). Laboratory studies have not been conducted to examine droplet size distributions when both oil and gas are discharged, and guidance is needed to relate lab results to field conditions when exit conditions are less idealized, such as in a pipeline rupture.
2. The buoyancy of the oil droplets and gas bubbles will form a buoyant plume with the gas providing the dominant source of buoyancy (if present). Near the point of release, this plume will behave like a single-phase plume. Though slight leakage of entrained seawater and fine oil droplets can be expected in the lee of the plume, basic plume features in this near source region can be easily described with conventional integral plume models.
3. Above a certain height, ambient stratification and/or ambient currents will conspire to separate the dispersed phase(s) from the entrained water. Above a current speed of roughly 2.5 cm/s, the current is the major factor and separation can be expected at elevations of order 180 m or less. The CDOG and DeepBlow models treat this separation somewhat differently. However, as the plume stage is short compared with the water depth, differences in plume dynamics are relatively unimportant in determining the fate of oil released at depths of 800-1000 m.
4. Above the point of separation, gas bubbles and large oil droplets rise toward the surface, while small oil droplets continue with the entrained seawater as a buoyant jet. The latter can be simulated with traditional integral plume models, while the former must be simulated as diffusing buoyant droplets (and bubbles). DeepSpill experiments show that some of the oil surfaces more rapidly than expected based on the individual rise velocity of the fastest rising (largest) oil droplets, suggesting some group or secondary plume effects. The greater than expected rise velocity means that the oil will surface closer to the release point. However, the fact that
only a small fraction of the diesel oil was recovered at the surface suggests that much of the oil could have been contained in the form of much finer droplets that are much more widely dispersed. Slicks from a submerged oil release are thinner than those resulting from surface spills allowing them to weather more rapidly.
5. At ocean depths below about 450m, natural gas hydrates are thermodynamically stable. Hydrates could form as thin skins surrounding gas bubbles, which would reduce the bubbles’ rate of dissolution, or as solid hydrates, which would significantly reduce bubble buoyancy. However, the UH laboratory studies suggest that hydrate formation requires relatively high background gas concentration, as well as significant induction time, neither of which are likely to occur due to the dilution caused by plume entrainment. The UH results suggest that the presence of oil on the bubbles can further impede hydrate formation. These conclusions are consistent with the DeepSpill field experiments (where hydrates were not observed), but not the model predictions. DeepBlow does not model the kinetics of hydrate formation (if hydrates are thermodynamically stable, solid hydrates are presumed), so SINTEF turned off the hydrate sub-model based on their observations. CDOG has a more detailed hydrate kinetic formulation, allowing it to predict a thin hydrate film; with such films Clarkson was able to match observed bubble rise heights in the DeepSpill experiments, but possibly for the wrong reason.
6. Echo sounders provide efficient tracking of oil and gas releases in the field and showed that the gas was completely dissolved before it could surface. This suggests that it may be safe to operate machinery directly above the spill without a danger of explosion.
7. The models that have been compared in these studies have evolved over time, at least in part because of the experimental studies and the model intercomparisons. As such the value of the last three (model comparison) activities has been as much in spurring model development as in identifying the “best model”.

[LaMenchos]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

BP Blowout: ?Most vigorous methane eruption in modern human history?
By oilflorida, on June 19th, 2010


Gulf oil full of methane, adding new concerns, Associated Press, June 18, 2010:

...

The oil emanating from the seafloor contains about 40 percent methane, compared with about 5 percent found in typical oil deposits, said John Kessler, a Texas A&M University oceanographer ?
?
?This is the most vigorous methane eruption in modern human history,? Kessler said.
?
In early June, a research team led by Samantha Joye of the Institute of Undersea Research and Technology at the University of Georgia investigated a 15-mile-long plume drifting southwest from the leak site... found methane concentrations up to 10,000 times higher than normal, and oxygen levels depleted by 40 percent or more.

? some parts just shy of the level that tips ocean waters into the category of ?dead zone? ? a region uninhabitable to fish, crabs, shrimp and other marine creatures. ?

Full article:

http://www.floridaoilspilllaw.com/bp-blowout-most-vigorous-methane-eruption-in-modern-human-history

[LaMenchos]

Re: Methane in water of Gulf 'astonishingly high'-US scientist

Florida Gulf oil spill: EPA monitors air quality, methane gas, oil spill health risks for residents
June 22, 11:38 AM Tampa Gulf Oil Spill Examiner MARYANN TOBIN

http://wwww.examiner.com/x-55371-Tampa-Gulf-Oil-Spill-Examiner~y2010m6d22-Florida-Gulf-oil-spill-update-EPA-monitors-air-quality-methane-gas-Tampa-oil-spill-health-risks

...

Residents along the Gulf coast from the Florida panhandle to the Tampa Bay area are at risk for health threats from the BP oil spill. Large amounts of toxic methane gas are being released, along with the continuing flow of oil.

The EPA has established a monitoring stations to determine air quality throughout the Gulf coast region. According to reports, ?The levels of hydrogen sulfide EPA is reporting in some areas could cause short-term symptoms in sensitive people and could potentially pose a long-term risk if the elevated levels continue. ?

In an effort to keep leaking oil from the Deepwater Horizon away from land, the federal government has authorized BP to burn millions of gallons of surface oil, which further degrades air quality. Burning large amounts of oil creates toxic gas air pollution in the form of sulfur dioxide, carbon monoxide and other toxins.
The EPA has issued a press release for Florida residents called a 'Trigger Response Plan. The three phase plan includes monitoring, surveying and responding.
...

Florida BP oil spill UPDATE: Oil spill map moves slick closer to Tampa Bay area