I was having a conversation with spouseinbox the other day during which she read some post arguing the concept that we needed to avoid substance x. After all, substance x was only an atom away from being plastic. (inhalation sounds, hands to the face, look of horror) AHHHH! the horror! Eating plastic. Who could consider such a thing. Of course, that atom difference has to be feared and substance x avoided. Well, my problem with hearing this sort of information is that I have had a year of organic chemistry. In other words, I have had some education. There is an interesting molecule called glucose. It is an interesting set of atoms in a particular arrangement forming a ring with a little finger sticking out one side. Glucose molecules form chains where that finger joins another molecule of glucose and then the chain grows to form starch. I educate my diabetic patients that the starch they eat is simply glucose in a chain, and the liver is rather efficient. High amounts of starch will elevate blood glucose, because the basic molecule is glucose. Change the joint between glucose molecules, and the substance is cellulose. Yes, wood. So the difference between food and house building material is the fashion that the molecules are joined. Am I going to get excited about different molecules when one is plastic? Not hardly.
This brings another memory of an exchange at the end of one of my organic chemistry classes. I liked to sit in the front row and take notes as it was easier to see the board and hear the prof without extra distractions that the other students may bring. There was a girl next to me – hearing the same lecture, seeing the same board. The professor was speaking about ozone. The formation of this molecule is absorption of energy from light breaking a molecule of O2 into radical components – atoms without a full set of electrons, at which point the reactive atoms cause further breaks in other molecules and attach in a dynamic fashion to form the O3 molecule. Dynamic fashion means that these molecules are not stable and continually form and break bonds. My seat mate mentioned at the end of class the problem with us destroying the ozone layer. After a moment of shock that we heard the same information and she was still in propaganda mode I had to mention that the information showed the only way to remove the ozone layer was to either get rid of oxygen, or sunlight. As long as both were present, ozone was a natural product. My seatmate, hearing the same lecture, again returned to the propaganda. This does demonstrate that education doesn’t necessarily combat the propaganda consistently presented by our media.

Additional information: here is a site with drawings of the molecules for anyone interested. I can’t see the plugins on the page with this computer, so can’t swear to what they show.