A man hold a syringe up to a man's neck and whispers into his ear, "One move and I'll empty this syringe of air into you." The man moves, the syringe full of air goes in and he falls down dead.Oh, scary. The problem is, is it factual? Can a syringe of air kill of person.
The answer: Maybe but unlikely.
Here's the facts:
1) Bubbles of air in the circulating blood CAN cause death or brain damage, if the air bubble cuts off the blood supply to your brain.
2) Small amounts of air often get into the blood circulation accidentally during surgery and other medical procedures (for example a bubble entering an intravenous fluid line), but most of these air emboli enter the veins and are stopped at the lungs, and thus a venous air embolism that shows any symptoms is very rare.
However, according to Dr. Barry Wolcott MD, FACP, senior vice president of clinical affairs for WebMD Health, "In general, the small amount of air that can be introduced by a typical syringe is not large enough to cause a fatal air embolism (an air embolism is similar to a blood clot)."According to many of the sources I found, a human would need around 150-200cc of air (like a bycicle pump) to cause any damage. The average syringe is only about 20cc of air. (The syringe in the photo above is only 12cc) Also, you would need to get it in to a vein or artery. If it hits a muscle, it does nothing. So, the murderer would have to be skilled at finding veins and injecting enough air to do damage. Not easy to do.
On a side note: (Please, don't try this at home. I don't want to be held responsible.) One way I found of causing death by air embolism is by blowing into the vagina of a pregnant woman during oral sex. Did you know that? That could, however, be used in one of your murder mysteries.
1) The Straight Dope
2) Fortune City
4) NHS Wales
5) Medical News Today