link: [link to www.howtodothings.com
How To Recognize Symptoms of Methane Gas Poisoning
"As methane gas tends to displace the oxygen in your system, methane gas poisoning will likely show signs similar to that of suffocation. Early symptoms may include headaches and dizziness. This is because your brain is being deprived of the oxygen it needs to function properly. Some people may not notice these symptoms, however, and will only realize something's wrong when they begin gasping for air. In cases like these, it isn't uncommon for people to collapse from the lack of oxygen. If this happens to you, and you aren't brought to an open, well-ventilated area, you'll continue to asphyxiate and ultimately perish.
Methane also creates another dangerous byproduct - carbon monoxide. Depending on the concentration of carbon monoxide in the air you breathe, you could be dead in less than three minutes. In common cases, however, you'll develop headaches and nausea within twenty minutes to an hour. The damage carbon monoxide can do to your body can even reach your heart. Extremely serious cases, however, will cause you to hallucinate. It can cause convulsions, an irregular heartbeat, and high blood pressure as well.
What is difficult about diagnosing methane gas poisoning is that most people simply brush off the signs, as symptoms of other conditions, like depression, migraine, and chronic fatigue. While the chances of you getting poisoned by methane gas are very, very low, it's still best to be aware, especially when your health is concerned."
Was curious, so i looked it up, could have relevancy.