by Alex Powell

Created on: July 28, 2007

When considering the risks of carcinogens, you must consider that if a substance can cause cancer, it is a carcinogen. However, this does not mean that this substance is dangerous per se. For example, sunlight (or the UV component of sunlight) can cause cancer (and is therefore carcinogenic) but we still readily expose ourselves to it. Only in high-intensity sunlight, when chances of carcinogenisis are high, do we consider protection such as sun block.

The primary causes of cancer are chemical carcinogens (some of the main ones being nicotine and asbestos), ionizing radiation (generally associated with radioactive sources, but also UV radiation is included here) and viral infections. Cancer can also be caused by hereditary disorders such as Down's Syndrome, as well as immune deficiencies.

Each one has the potential to cause cancer by altering the genetic information in the cell. Every cell has the potential to divide in a process called mitosis, where the cell divides, producing 2 identical 'daughter cells'. The BASIC mechanism through which cancerous legions occur is (reasonably) simple. When the genetic information in a cell that codes for mechanisms that regulate the mitotic process in the cell are damaged by a carcinogen, the cell forms what is known an oncogene, a growth promoter. However, this is not necessarily a problem because there are also tumor suppressing mechanisms within cells and when uncontrolled mitosis (division) begins, these cause apoptosis eventually destroying the 'faulty' cells. True cancer can only occur with oncogene formation and breakdown on the tumor suppressing ability of cells, and uncontrolled mitosis.

For both these mutations or disruptions to occur in the cell's genetic information is fairly rare, as carcinogens (or, more accurately, mutagens - substances that cause genetic mutation) damage any part of the DNA coding, and so generally cause instant apoptosis (cell death).

Thus, it can be said that the hazards or risks of carcinogens are minimal, except in a few cases, such as strongly ionising radiation (from radioactive isotopes) or substances such as asbestos (which is the main cause of mesothelioma, a very specific cancer of the lung lining) that are particularly dangerous. Articles make claims that can essentially referred to as 'scare-mongering', suggesting that charred foods are full of carcinogens and therefore are dangerous, seem to forget that we are surrounded by carcinogens and free radicals, but that this does not mean we all die of cancer.

Learn more about this author, Alex Powell.
Click here to send this author comments or questions.