My question is prompted by a report I saw on TV today…supposedly, CHARLESTOWN (W. Va) is the most concer=prone US city. It is speculated that this might be due to the coal mining industry, or the high rate of cigarette smoking there…but nobody really knows. Anyway, we have been studying cancer for over 100 years, so I’m wondering:
-are most cancers environmentally induced? Is living in an area with a lot of chemicals (like around petroleum refineries) hazardous to your health?
-can you avoid most cancer by living in a “healthy” area?
-the USA has had a law on the books for 30+ years now, saying that no proven carcinogenic chemical can be used in food products…has this helped?
Overall,is cancer incidence increasing or declining? I’m hoping I’m doing things right-I don’t smoke, and I drink moderately. I also try to eat right. :eek:
Tobbacco is the main culprit. Environemtal causes are way overblown. It’s discussed in one of the chapters of The Flight From Science and Reason.
I can’t think of a scientific reference to back this up, but most things I’ve read say that the overall incidence of cancer is increasing. This may be because of increasing lifespans and our ability to detect cancer early, though environmental factors are also significant.
Cancer arises when cells begin to grow out of control, and stop self-destructing at the end of their useful lifespans. Ultimately, it is caused by damage to DNA. Your body has many genes that cause cancer if they are damaged; for example, there are genes that prevent cancer from forming, and cause cancer if they are damaged. Genes that regulate cell growth and cause programmed cell death can also cause cancer if they’re damaged. So, an important factor that determines whether an individual develops cancer is where in their DNA damage occurs.
Factors that cause cancer are not always environmental, though some are. Besides evil synthetic chemicals, ordinary foods also contain pathogens that might cause cancer. Exposure to UV light can cause cancer. The most insidious threat is the byproducts of your body’s own metabolic processes. Many biochemical processes result in reactive byproducts that can damage DNA if they are not quickly neutralized. Exposure to cancer-causing agents is necessary to cause most cancers (and is inevitable), but what really causes cancer is your body’s ability to neutralize these agents before they damage DNA, and to repair damage to DNA after it occurs. Your body’s ability to protect and repair your DNA is the single most important factor in determining whether you will get cancer, and that’s up to your genes.
So, you cannot avoid most cancer by living in a ‘healthy’ area. Not smoking will help, eating a healthy diet (particularly one high in antioxidants) will help, and so will many other things. But you cannot avoid the free radicals that your body produces, or the sun, or ubiquitous cancer-causing agents present in foods or the air. It’s possible that some areas have a low incidence of cancers because of the genetic makeup of the people that live there – for example, maybe Charlestown was settled mostly by people who had a genetic predisposition to cancer. (It could also be because of coal or smoking, of course.)
If you have no family history of cancer, it is less likely that you will get cancer. Regardless of your family history, there are things you can do to decrease the likelihood you will develop certain cancers, and there are things you can do to increase your chance of surviving if cancer develops.
Yeah, what Roches said.
There are things you can do: Don’t smoke, make sure your work limits your exposure to carcinogens, test for radon in your house if you live in a high-radon potential area, eat healthy (though you don’t need to obsess about it), and don’t play with nasty chemicals (roughly in order of decreasing importance). But these things are no guarantee; they just better your odds by a little bit. Also, to catch at an early stage any problems, get regular check-ups, and make sure you’re aware of any family history of cancer.
As I mentioned, the most likely issue with where you live is the potential for radon – a radioactive gas – in your basement. But the answer here isn’t move to a different state but rather set up appropriate ventilation if tests show high levels. More info: http://www.epa.gov/NE/eco/radon/index.html
Yes. Check out “Living Downstream” by Sandra Steingraber . She is an epidemiologist, ecologist, cancer survivor, and also a very good storyteller.
Steingraber examines the following lines of evidence indicating that certain chemicals (and radiation) can cause cancer in living things:
** cancer in workers exposed to chemicals;
** studies of non-worker human populations exposed to chemicals out of ignorance or by accident or by misguided public policy (for example studies of humans who contract cancers from exposure to chlorinated drinking water);
** cancer in immigrants who soon exhibit the cancer rates of their adopted countries, rather than the cancer rates of the place where they were born;
** maps showing more cancers in urban areas than in rural;
** maps showing more cancers in rural counties with heavy pesticide use vs. rural counties with low pesticide use;
** individual studies revealing cancer clusters near chemical factories and near particularly-polluted rivers, valleys, and dumps;
** rising rates of childhood cancer. The lifestyles of children have not changed much in 50 years; they do not smoke, drink alcohol, or hold stressful jobs, yet childhood cancers are steadily rising;
** cancer in fish and shellfish living in polluted bodies of water. In North America there are now liver tumor epizootics (the wildlife equivalent of epidemics) in 16 species of fish in at least 25 different fresh-and salt-water locations, each of which is chemically polluted. In contrast, liver cancer among members of the same species who inhabit nonpolluted waters is virtually nonexistent.
** many kinds of cancer that can be induced in laboratory animals by exposing them to certain chemicals;
** cellular studies indicating that certain chemicals can cause cell growth and division;
** studies showing that chemicals can damage the immune system and the endocrine system, promoting cancers.