Sunlight, bacon, and plutonium are all on the Group 1 Carcinogens list.
You have probably seen the recent news that the World Health Association's International Agency for Research on Cancer has classified bacon and other processed red meats as Group 1: Carcinogenic to humans. This has the news media buzzing, but before you get too excited, be sure to check out the science that is involved.
Group 1: Carcinogenic to humans is a group of substances or conditions that are known to cause cancer in humans. If you read the list, you will see some very dangerous things, but you may be surprised at some of the things on the list that don't seem that dangerous.
How can sunlight be in the same category with plutonium? To understand that, you need to understand what this list includes. The list tells you the things that are known carcinogens, but it does not tell you anything about the level of exposure or the risk factors involved. Some of the substances have very low risks while others have very high risks. The only thing the list tells you is that with enough exposure, these things can cause an increased risk of cancer.
So what is the cancer risk for eating bacon? From the statistics I could find, they stack up like this.
If you took a group of 100 people who did not eat any processed meats or red meat for their entire life,
you would expect 6 out of the 100 to get colon cancer.
If you took another group of 100 people who ate a bacon sandwich every day of their life,
you would expect 7 out of the 100 to get colon cancer.
You may see articles that say processed meats increase your risk of cancer by 18%. That is true, although from the information above it seems that the increase is only 1%. Multiply 0.18 (to get 18%) times 6 (the usual risk per hundred people). You will get 1.08, which is the extra person per hundred in the group that eats processed meats every day. Depending on how it is phrased, this can make the risk seem higher than it actually is.
That may not seem much of a risk, but as you start adding other carcinogens (a sun tan, air pollution, alcoholic beverages, etc.) the odds of getting cancer at some time during your life increase. It is important for us to understand the risks involved in our lives, so we can make informed decisions. It is also important for us to understand the level of those risks, so that we don't overreact every time the news media tells us that something is going to kill us.