Here is a news item – a freak accident in which all the incumbents in the car succumbed to this air conspiracy. This is an eye opener for all of us who use air conditioned cars for commuting.
When water & air conspire to kill
Chennai: A car can be a deadly place to be in an automobile accident. And then, you can die while simply sitting in a parked car, its engine running, the windows up and the air-con running. The freak accident that recently involved three Chennai-based young software engineers in a Santro is an illustration of how death can strike viciously and silently while doing nothing less innocuous than sitting in a car. Now, though knowledge of the circumstances in the incident is still forthcoming, a post mortem report of the three people points a probable finger at the cause of death — a heavy amount of carbon monoxide in the lungs.
Here’s a possible reconstruction of the tragedy. The three colleagues decide to head out in the car and find themselves stuck in a logjam of cars stranded in heavy rain and the flooding on G.N.Chetty Road. They decide to wait out the situation with the windows up — the rain otherwise would get into the car. The air-conditioner is running and set on `recirculate’ — a mode people normally use to prevent the smellier components of urban air pollution from getting into the car. The engine is running to keep the air con functioning.
In the meantime, water is rising below and around the car, and this means the hot exhaust gas, which normally has a larger volume of air to disperse into, is suddenly crowded up against the undersides of the car’s floorboards. The situation might be more adverse if the car’s exhaust system has a leak somewhere and all emissions are not properly exiting at the tailpipe as they are meant to. The gases might therefore be building up more heavily than normal under the car and inside the engine bay. And invariably, this gas will get into the car through the tiny access holes present in these regions — the little holes on the floorboard that drain water from inside a car, the innumerable gaps and holes that route wiring, cabling and mechanical controls like the steering column through the engine bulkhead — the wall that separates the engine bay from the passenger cabin. In the meantime, the air-con is steadily recirculating the deadly gases through the cabin of the car — and a silent and deadly killer gas — carbon monoxide — goes to work, poisoning the unwary occupants.
How does CO kill?
Carbon monoxide, or CO, is one of the gases emitted by your car’s exhaust system. It is completely imperceptible to the human senses, being odourless, colourless, tasteless. And this poison is doubly deadly, as it gets absorbed into the bloodstream quickly — the haemoglobin in blood has a much greater affinity for this gas than oxygen, forming a strong bond that is devastating in nature — it starves organ tissues in the human body of vital oxygen. Symptoms of CO poisoning are things you’d shake off as the result of a stressful, long day at work — headache, dizziness, nausea and fatigue. And then you might decide to sleep it off for a while…