A decade ago, a doctor who was asking about my health habits told me I should cut my two daily cups of coffee to one. Coffee was, at that time, still on the "bad" list. These days, I think it's on the "good" list or at least the "neutral" list. So it goes with eggs, wine and other products that are considered good for you one moment, and bad the next.
In October 2015, the International Agency for Research on Cancer (IARC) compiled a comprehensive "bad" list of its own: 116 substances and activities that are known to cause cancer. (Note that red meat didn't make the list; it's only a possible carcinogen at this point.)
While the list includes exposures, mixtures and agents that you probably won't be exposed to — unless you're a chimney sweeper, painter or cabinet maker — the list also includes things we can all take precautions against. In case you were still unclear on any of these, here are the top 11 substances that can cause cancer:
1. Tobacco smoke. Smoking the leaves of the tobacco plant through a cigarette, cigar, pipe or hookah pipe causes cancer.
2. Sunlamps and sunbed tanning. Tanning equipment emits UV radiation that overexposes you and causes skin cancer, cataracts and premature aging.
3. Secondhand smoke. A non-smoker's risk of getting lung cancer can increase by a quarter simply from breathing in other people's smoke. It also can increase your risk of cancers of the larynx and pharynx. Your pets won't like it, either.
4. Alcohol. Alcoholic beverage consumption is a known cause of breast, colorectal, larynx, liver, esophagus, oral cavity and pharynx cancers, and the IARC labels it a probable cause for pancreatic cancer.
5. Smokeless tobacco products. Chewing smokeless tobacco products causes cancers specific to the larynx and the mouth.
6. Processed meats. Meat that is cured for preservation or taste like bacon, sausage and ham is as dangerous a carcinogen as tobacco, according to the World Health Organization. Processed meat is linked to bowel cancer.
7. UV rays. Yes, the sun can cause cancer.
8. Contraceptives. Both combined forms (those that contain both estrogen and progesterone) as well as sequential oral forms of hormonal contraceptives (a period of estrogen followed by a period of progesterone and estrogen) were ranked as cancer-causing by the AIRC. Breast, cervical and liver cancer risk may be increased. Endometrial and ovarian cancers may be decreased.
9. Estrogen therapy (post-menopausal). Women who take estrogen and progestin were more likely to be diagnosed with breast cancer.
10. Outdoor air pollution. It can lead to lung cancer and an increased risk of bladder cancer.
11. Salted fish (Chinese style). Diets high in salt-cured meats and fish, or pickled foods that are typical in Asian diets, can increase the risk of nasopharyngeal cancer, in the upper throat behind the nose.
A few more specific risks with regard to chemicals, disease and occupational hazards include arsenic that ends up in drinking water from alloy manufacturing; the leather dust, benzene and solvents in boot and shoe manufacturing; iron and steel founding; magenta dye manufacturing; roofing with coal tar; manufacturing rubber; diesel exhaust; soots; asbestos; hepatitis C; the human papillomavirus; and tamoxifen.