Carcinogens I Have Known And Loved

Disclaimer: I have neither known nor loved these substances, but I like catchy post titles. So sue me.

Mustard gas

Bastard of a chemical. Let's say you get exposed to it. Great. Nothing happens right away. But then a couple of hours later these terrible blisters develop wherever the gas came in contact with your body. If it got in your eyes, you can go blind. If you breathed it in, it does a right number of your respiratory tract and can cause you to drown in your own body fluids (see: pulmonary edema). To top things off, it causes cancer. The only good thing I can say about it is this: it is responsible for the first anticancer drug. During WWII a stockpile of the gas was blown up (this happens in wars) in Italy, resulting in lots of people getting exposed to it. An interesting trend was noted, where those who were exposed to the gas had decreased white cell counts. Since Hodgkin's lymphoma (a type of cancer) was known to originate in lymphocytes (a type of white cell), researchers decided to see if they could use the gas to selectively kill the cancer cells (plus normal white cells, of course). They could, and the result was mechlorethamine (Mustargen), an analogue of mustard gas that ushered in the era of treating cancers directly with drugs. Two of the dudes who worked on this project, Louis Goodman and Alfred Gilman, went on to write a rad pharmacology textbook that is now the undisputed go-to resource for that wonderful field of science.


Heterocyclic amines

These bad boys (and girls) are primarily made when muscle meat (as opposed to organ meat) is cooked at high temperatures. We're talking frying, broiling, and barbecuing. Consumption of meats containing these chemicals has been linked to a number of cancers including stomach cancer, making it fairly likely that they are the cause. How does one go about minimizing exposure to these things, you ask. The key is to eat your stakes rare, microwave meats prior to cooking them (um...okay), and avoid gravy (the amines are concentrated in meat drippings, from which gravy is usually made).


Formaldehyde

Best known as the preservative agent in embalming fluid, this mofo has also found medical/scientific use as a disinfectant, a means of treating warts, and as a way of fixing tissues or cells so that they can be looked at under a microscope. It has plenty of industrial uses as well. It permanently attaches proteins with each other and with DNA, damaging or killing cells (if they are alive) and preventing tissues from liquifying, thus permitting open caskets to be a reasonably tolerable affair. Aside from the whole, you know, person being dead and stuff. Since it can damage DNA, exposure to high levels of this compound over a long period of time, which usually occurs via the inhalation of fumes (see: sawmill workers, undertakers, lab workers), increases your risk of developing nasopharyngeal cancer. Drinking formaldehyde is a bad idea. The body converts it to formic acid, resulting in fun things like metabolic acidosis, blindness (the enzyme that makes formic acid is highly expressed in the retina), coma, and even death. It's worth nothing that methanol (wood alcohol) is converted to formaldehyde by your liver, and thus produces a similar symptomatology (yay, big word!) if you ingest it.


Hexavalent chromium

Oh, hexavalent chromium. Why must you damage DNA so? Pop culture reference point for my non-science peeps: Erin Brockovich. Inhalation of particulate matter formed from compounds that contain this form of chromium increases your chances of getting the lung cancer. Regardless of the route of exposure, the lungs are often affected because they contain a zillion tiny capillaries in which particles containing the metal can become lodged. It is reduced in the body (i.e. electrons are added to it) to pentavalent chromium (also carcinogenic), and then to trivalent chromium. Pentavalent chromium can be oxidized back to the hexavalent form, and it is thought that this process generates radical oxygen species (ROS), namely hydroxyl radicals, which can damage DNA, leading to mutations and possibly cancer.


http://www.cancer.gov/cancertopics/factsheet/Risk/heterocyclic-amines
http://en.wikipedia.org/wiki/Formaldehyde
http://en.wikipedia.org/wiki/Hexavalent_chromium
http://en.wikipedia.org/wiki/Sulfur_mustard
http://yalemedicine.yale.edu/ym_su05/capsule.html