▎ WuXi AppTec content team editor
Several fans quickly guessed the answer, yes, carbon monoxide poisoning.
What the hell is going on? Let's see the truth.
The last issue of the truth review
After the Spring Festival, Mr. Kang's family of three drove back by car.
Mr. Kang and his wife took turns to drive to rest, driving for 10 hours continuously, and encountered a traffic jam on a snowy day.
Image Source:
https://commons.wikimedia.org/wiki/File:Glen_More_traffic_jam._-_geograph.org.uk_-_133878.jpg#file under CC-BY-SA -2.0
Note that depending on the weather conditions here, it can be introduced - the car has a warm air conditioner.
In order to ensure the heating effect of air conditioning, the windows are generally closed, and some people will open the inner circulation. The same is true of Mr. Kang's car.
When there is a traffic jam, they do not turn off the air conditioner or open the window, and the carbon monoxide in the exhaust of the car is inhaled from the ventilation system into the car, causing carbon monoxide poisoning.
However, the symptoms of poisoning are not obvious at first.
For example, the 3-year-old daughter began to be restless, Mrs. Kang felt weak, dizzy, and her hands and feet were numb.
But at that time, she only thought that "a little bit of motion sickness, a nap is good", who knows just fainted...
Fortunately, he was sent to the hospital in time and finally turned the corner.
Popular science time
There is no need to say more about the principle of carbon monoxide poisoning - carbon monoxide will "forcefully rob" the hemoglobin combined with oxygen, leaving the body short of oxygen.
Friends who have studied chemistry know that carbon-containing compounds (such as oil, diesel, natural gas, honeycomb coal, charcoal) will produce carbon dioxide when completely burned, but when oxygen is not enough and the combustion is incomplete, it is easy to produce carbon monoxide.
Therefore, carbon monoxide poisoning does not only occur in the kitchen, bathroom, restaurant, but also in the car!
When the car is driving, the air conditioning ventilation system can convect the air in the car, and the carbon monoxide concentration is very low, so Mr. Kang's family did not feel uncomfortable during the drive.
Image credit: https://commons.wikimedia.org/wiki/File: Heat_Wave_ (4771656759) .jpg #file under CC-BY-2.0
During traffic jams, on the one hand, the car idles for a long time (stopping in place without stepping on the accelerator, the engine is empty), which will produce more carbon monoxide.
On the other hand, the doors and windows are closed, the air in the car cannot continue to convect, and the carbon monoxide emitted by the engine may leak into the car from the gap.
Of course, many new cars now have catalysts that can purify carbon monoxide.
But in some old cars, the catalyst activity has become lower, the emission performance and tightness have also deteriorated, and carbon monoxide may slip in from various crevices, and the concentration will be higher.
For example, in 2000, on a long-distance bus in Shandong Province, there was a collective poisoning incident of carbon monoxide, a total of 57 people were poisoned, and 2 people died on the spot, because the exhaust gas entered the car from the gap in the floor of the car.
At that time, the weather was cold and the air did not circulate. Everyone thought it was motion sickness and sleeping in the car, which did not arouse enough vigilance.
Image credit: 123RF
So, opening the internal circulation may be dangerous, is the outer circulation safe? Be careful too!
The study found that if the air conditioner + external circulation is turned on when the traffic jam is blocked, even if the engine is turned off, a large amount of exhaust gas emitted by other cars outside will be sucked into the car, making the carbon monoxide concentration in the car become higher.
Therefore, it is recommended that you often drive or take a car friend:
Long-distance driving, it is best to get off the car more on the road to rest, do not stay in the car for a long time.
When stuck in traffic, don't open the window because you are afraid of cold and heat! At this time, the internal/external circulation is not safe enough, even if the air conditioner is turned on, it is necessary to open more windows for ventilation.
When the traffic jam is too long, the engine can be temporarily turned off, and people who do not drive can get out of the car to breathe.
When traveling at home, it is best to give an extra spare key to the person who gets off the car, so as to avoid an accident after locking the car but not being able to open the door and delay the time to save people.
Try not to stop and sleep, even if it is just a "nap", it is very dangerous. Especially indoor spaces such as underground parking lots are more likely to die of lack of oxygen.
If you have to stop and rest, it is best to find a place for outdoor air circulation, turn off the engine, do not turn on the air conditioner, but the window must open a gap (the hand can not reach in from the outside), and report the positioning to the family or close friends before going to bed, just in case.