CH4 | Methane | Sources and Impacts| OIZOM Academy
Channel: Oizom
Date: 2021-01-06

Methane has a direct influence on climate change as well as an indirect effect on human health, plant yield, and productivity due to its role as an important precursor to ground-level ozone formation. CH4 monitoring is an efficient way to detect the buildup of CH4 levels and take necessary actions. This article covers information on methane gas, its sources in the ambient air, permissible levels, health and environmental impact, possible corrective measures, need for methane monitors as well as different methods of CH4 monitoring.

What is CH4?
Methane (CH4) is a colorless, odorless, tasteless, non-toxic gas composed of one carbon and four hydrogen atoms. It is a major component of natural gas. CH4 is highly flammable at very high concentrations of about 50,000 ppm.  Methane is considered an asphyxiant at extremely high concentrations.


Formation of Methane
According to the World Meteorological Organization Global Atmosphere Watch Programme, the current average global background level of methane is 1824 ppb. Approximately, natural resources emit 40% of methane and human activities including intensive livestock farming cause emission of the other 60%.   


Health & Environmental Impact of CH4
Health Impact
Methane is not toxic in nature and does not harm at low levels. However, it displaces oxygen causing asphyxiation at high concentrations. A human requires about 18% of the oxygen to breathe, hence at high methane levels in confined spaces becomes extremely dangerous.

High-level exposure of CH4 may cause suffocation, loss of consciousness, headache and dizziness, nausea and vomiting, slurred speech, mood changes, vision problems, memory loss, etc. In severe cases, it may also cause rapid breathing, loss of coordination, and numbness. Long term exposure can lead to coma and death

Environmental Impact
Methane is a highly potent greenhouse gas, second to carbon dioxide making it highly efficient in trapping heat. It is a major contributor to global warming. 

CH4 is a major precursor of another greenhouse gas, carbon dioxide. While converting to CO2 in the atmosphere, methane reacts to form volatile organic compounds and leads to the formation of ground-level ozone when mixed with NOx. 



Nondispersive infrared absorption (NDIR)
Methane absorbs infrared radiation at a particular frequency. When the gas sample is exposed to infrared radiation, the CH4 molecules present in the gas sample absorb the infrared radiation. This is measured by the detector in a non-dispersive photometer. 


Among all the above principles of CH4 monitoring, methane monitors based on the principle of NDIR are typically found to be preferred for ambient air monitoring as they yield more accurate CH4  concentrations.

Oizom’s working principle for CH4 monitoring
Oizom’s ODOSENSE is the real-time odour emission tracking solution. It continuously detects, measures, and monitors the odourful gaseous contaminants including hydrogen sulfide, ammonia, sulfur dioxide, methyl mercaptan, TVOC, formaldehyde, methane, and weather parameters like temperature, humidity, wind speed, and wind direction. The sensor that measures CH4 works on the principle of nondispersive infrared absorption  (NDIR). Odosense is a proactive approach to measure real-time odour emissions. This makes it an ideal choice for landfill sites, wastewater treatment facilities, fertilizers, paper-pulp industries, and soil-treatment sites, etc. 

Reasons why CH4 monitoring is important
CH4 is a colorless, odorless, tasteless, non-toxic gas that is naturally produced during the anaerobic decomposition of organic compounds. It tends to rise and accumulate near the higher, stagnant parts of enclosed spaces.
CH4 is the second most important greenhouse gas with 28 times higher global warming potential than carbon dioxide. Its presence in the atmosphere increases the abundance of other greenhouse gases such as CO2, O3, water vapor, etc. 
CH4 is an asphyxiant at higher concentrations leading to various issues such as suffocation, loss of consciousness, nausea, rapid breathing, numbness, etc. and may lead to coma and death. 
CH4 monitoring is an efficient way to detect the buildup of CH4 levels and take necessary actions. 
Real-time monitoring of CH4 levels helps in determining their source as well as formulating an action plan to control CH4 emissions.