Saturday, 7 December 2013

Week 11 of FYP 1

Date: 29/11/2013 (Friday)
Title: Detailed Research on Methane Gas


Methane Characteristics

Methane is an odourless gas and is lighter than air. Because methane is lighter than air, it tends to rise and accumulate near the higher, stagnant parts of enclosed buildings and tightly closed manure storage pits. It is most likely to accumulate during hot, humid weather.

Methane is extremely difficult to detect without gas detection instruments. Concentrations in confinement livestock housing are normally well below the levels that may be explosive; however, explosions attributed to methane have occurred around manure storage pits without proper vents.

Methane can displace oxygen in confined areas, resulting in an oxygen-deficient atmosphere. Methane can explode at concentrations of 50,000 ppm or more (a level of 5 per cent).


Health Effects

The Occupational Safety and Health Administration (OSHA) has no permissible exposure limit for methane, but the National Institute for Occupational Safety and Health's (NIOSH) maximum recommended safe methane concentration for workers during an 8-hour period is 1,000 ppm (0.1 percent). Methane is considered an asphyxiant at extremely high concentrations and can displace oxygen in the blood.




Methane exposure levels and effects



How are people exposed to Methane?


Breathing: Most exposures occur when people inhale methane. Methane can go into homes through sewer traps or foundation cracks. People can be exposed by inhaling the chemical at work, cooking on a gas stove, or entering confined spaces such as manholes, silos, animal waste pits, septic tanks and sewers.

Drinking/Eating: Because methane evaporates quickly, it is usually not found in food or drinking water. Very low level exposure can occur when contaminated water is used for drinking and/or for food preparation or when children eat contaminated soil.

Touching: Methane gas does not pass readily through intact skin. Methane in its extremely cold liquefied form can, however, cause burns to the skin and eyes.



Will exposure to Methane result in harmful health effects?


Immediately or shortly after exposure to oxygen levels of less than 15% in air, a person may feel tired, dizzy, and have a headache.




The following health effects can occur after several years of exposure to methane:

Cancer: Methane is not suspected of causing cancer.

Reproductive Effects: The reproductive and developmental effects of methane are not known.

Organ Systems: No long term health effects are currently associated with exposure to methane.

In general, chemicals affect the same organ systems in all people who are exposed. However, the seriousness of the effects may vary from person to person.

A person's reaction depends on several things, including individual health, heredity, previous exposure to chemicals including medicines, and personal habits such as smoking or drinking.

It is also important to consider the length of exposure to the chemical; the amount of chemical exposure; and whether the chemical was inhaled, touched, or eaten.


Can a medical test determine exposure to Methane?


Methane is rapidly eliminated from the body. Although methane can be measured in exhaled breath, urine, blood, and other tissues, no reliable method exists to determine the level of exposure. There are currently no tests available to evaluate the health effects of methane exposure.

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