FREE RADICALS ARE DANGEROUS
What is a "free radical" and why are they dangerous to us? It is any compound that has an odd electron somewhere in the molecule in a place where it is not supposed to be. This can cause a lot of trouble and make the molecule far more reactive than it would otherwise be. (Physicists will use the expression that the molecule has a "net magnetic moment". This will not mean much to most of us, but normally, molecules inside of us do not have this property.) Suffice it to say that when someone is suffocating it is the formation of free radicals that within minutes can cause irreparable brain damage. (Victims of drowning accidents in very cold water, can sometimes be revived even after a half hour of no breathing, because there may be little or no formation of these free radicals.) Why are free radicals of concern to us in the context of the causes of cancer? It is because a chemical reaction caused by a free radical molecule can result in a carcinogenic product molecule (such as a nitrosamine). (Mori et al 1969)