The City of Johannesburg announced on Wednesday methane gas caused the explosion that took place on Bree street (now called Lillian Ngoyi street) in the inner city.
The explosion made international headlines in mid-July with footage of the explosion going viral on various media platforms. One person died from the explosion and 48 others were injured.
Health-e News spoke to Guy Richards, Emeritus Professor of Critical Care and Pulmonology at the University of Witwatersrand about the public health implications of methane gas.
What is methane gas?
Methane gas can be understood as a natural type of gas that consists of hydrogen and carbon found in coal. Richards explains that it is similar to the standard gas that is used when cooking with a gas stove or when you are using a gas cooker outside to prepare food.
“It accumulates particularly in an agricultural setting and it also accumulates in mining settings, particularly in coal mines, but also in gold mines which are particularly deep.”
He notes that this is a problem for South Africa because the country has the deepest gold mines in the world.
What impact does methane gas have on health?
Richards says that the most important danger to health is the potential for explosion.
“If there is a lot of methane gas that has accumulated and there is a source for a spark it can set the gas on fire or cause an explosion.”
In terms of health effects, he says if a person is exposed to high levels of the gas, they start off with nausea, vomiting, and dizziness.
“If you remain there for long enough, you will ultimately go unconscious when exposed to large amounts. You would have to be removed quite rapidly so that you can get fresh air to flush out the methane gas you have been breathing in.”
How can these impacts be mitigated?
Richards says that the first thing is to try to avoid the accumulation of methane in any one spot. That’s not always easy.
“The problem being that although methane gas is much more common in coal mines, it also will appear or be produced in very deep gold mines and then gradually seep up to the surface.”
He notes that to decrease the impact of methane gas on health, it is important to upgrade all the electrical wiring in tunnel areas to prevent the potential for a spark igniting the methane gas – and an explosion.