A chemical’s properties are determined by the other chemicals that it is bound to.
Chemical compounds are made by combining different elements or even molecules, and the final product may not behave the same way as all of its individual parts. Sodium chloride is a classic example of this concept. Sodium is extremely reactive and will literally explode if it contacts water, and chlorine is very toxic at anything but an extremely low dose.
Worth your salt
Nevertheless, when we combine them we get sodium chloride, which is better known as table salt. Notice that table salt does not have the properties of either sodium or chlorine. It does not explode when it contacts water and you cannot get chlorine poisoning from it no matter how much of it you eat.
The combination of those two elements changed their properties and it would be absurd to say that “salt is dangerous because it contains sodium.” The sodium in salt no longer behaves like sodium because it is bound to the chlorine. Therefore, when you hear a claim that something contains a dangerous chemical, make sure that the chemical isn’t bound to something that makes it safe.
Thimerosal in vaccines makes an excellent illustration of how little anti-scientists actually understand about chemistry. You have no doubt heard that vaccines are dangerous because they contain mercury, and mercury is toxic.
Ignoring the fact that currently only certain types of flu vaccines contain mercury and the fact the mercury is present in very low doses, there is another serious problem here. The mercury in vaccines is in a form known as thimerosal.
Thimerosal is mercury bound to an ethyl group, making it ethyl mercury. The mercury that causes poisoning (i.e., the form that accumulates in seafood) is mercury bound to a methyl group (a.k.a. methyl mercury).
Ethyl and methyl mercury are not the same thing. They do not behave the same way. Just as the properties of the sodium were changed by the chlorine, the properties of the mercury are changed by the ethyl group. So, claiming that “mercury is dangerous and vaccines contain mercury, therefore vaccines are dangerous” is no different from claiming that “sodium is dangerous and salt contains sodium, therefore salt is dangerous.”
Part 5 of the wonderful article 5 simple chemistry facts that everyone should understand before talking about science by The Logic of Science website – posted on May 27, 2015. Find the original article here.
Content and images courtesy of The Science of Logic website.