Methane: Exposure and It's Effects

BACKGROUND     

Methane is a colorless, tasteless gas which is the primary component of natural gas. It is present beneath the earth’s surface in vast quantities, but levels in the atmosphere are relatively low. Methane is produced naturally by volcanoes, ruminant animals such as cattle and sheep, decaying plants, extraction of natural gas, coal mining and waste disposal such as landfills. It is a major ‘greenhouse gas’ that results from such human activities.

Methane can be released into the environment during its extraction from the earth, emissions from industries, agriculture, distribution and use in residential and commercial buildings. A large quantity of the gas is released from decaying rubbish in landfill sites. Methane released into soil or water will eventually escape into the air where it will degrade slowly in the atmosphere by sunlight.

Exposure

• 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 or 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.

 Health Effects

• Inhalation:

Low concentrations are not harmful. A high concentration can displace oxygen in the air. If less oxygen is available to breathe, symptoms such as rapid breathing, rapid heart rate, clumsiness, emotional upsets and fatigue can result. As less oxygen becomes available, nausea and vomiting, collapse, convulsions, coma and death can occur. Symptoms occur more quickly with physical effort. Lack of oxygen can cause permanent damage to organs including the brain and heart.

•  Skin Contact:

Not irritating. Direct contact with the liquefied gas can chill or freeze the skin (frostbite). Symptoms of mild frostbite include numbness, prickling and itching. Symptoms of more severe frostbite include a burning sensation and stiffness. The skin may become waxy white or yellow. Blistering, tissue death and infection may develop in severe cases.

• Eye Contact:

Not irritating. Direct contact with the liquefied gas can freeze the eye. Permanent  eye damage or blindness can result.

• Ingestion:

 Not a relevant route of exposure (gas).

First Aid

You should remove yourself from the source of exposure. 

If you have got liquefied gas on your skin, remove soiled clothing, wash the affected area with lukewarm water and soap for at least 10-15 minutes and seek medical advice. If you have inhaled high levels of methane seek medical advice

Learn more at http://methaneeducation.weebly.com

References:

https://www.dhs.wisconsin.gov/chemical/methane.htm
https://www.ccohs.ca/oshanswers/chemicals/chem_profiles/methane.html