How severe are environmental impacts on cancer?
There are certain types of cancer that are difficult to lessen our risk; for example, it is now common knowledge that if we carry a BRCA gene, we are at a much higher risk for developing breast cancer. However, our environment is constantly changing. Environmental impacts to our genes can change the way that our cells function, causing damage to our DNA. When this occurs, cancer can occur. Environmental impacts on cancer are noteworthy, however some of them can be avoided.
Most Common Carcinogens
The National Toxicology Program’s 14th Report on Carcinogen’s listed the substances that were most likely to cause cancer; however, just because a person is exposed to a carcinogen does not mean that they will develop cancer. There are other factors at play, such as the length of time the person is exposed as well as genetic background.
The report found the following to be most likely linked to cancers:
- Aristolochic acids
- Coal tar and coal tar pitch
- Coke oven emissions
- Crystalline silica
- Ethylene oxide
- Hexavalent chromium compounds
- Household combustion of coal
- Mineral oils
- Nickel compounds
- Secondhand smoke
- Strong inorganic acid mists containing sulfuric acids
- Vinyl chloride
- Wood dust
Experts are still trying to figure out how large of an impact environment plays in the development of cancer.
In past years, experts believed that environmental impacts contributed to about 6% of cancers. However, in 2010, a report by the President’s Cancer Panel “…reignited a 30-year-old controversy among cancer experts and environmental epidemiologists about how large a role environmental factors play in the No. 2 killer of Americans… But scientists most likely will never be able to tease out the true role of environmental contaminants because environmental exposures, genetics and lifestyle seem to all intertwine.”
We know that smoking is attributed to approximately 30 percent of cancer deaths, another 30 percent is attributed to obesity, diet, and lack of exercise, and the other 30 percent is attributed to – what? Presumably, they could be related to environmental factors, but experts are unsure.
Margaret Kripke, a professor at University of Texas M.D. Anderson Cancer Center, believes that, although the environmental component is a possibility, there are limitations. For example, we could consider a person who develops lung cancer who smokes and lives in an area with high pollution. The fact that the person smokes is a real consideration – 90 percent of lung cancers occur in smokers. However, pollution exposure can’t be dismissed.
According to Scientific American, “The major reason that it’s so difficult to pin down how many cancers are due to environmental factors is that studies that allow epidemiologists to link human cancers to an environmental pollutant are rare opportunities.”
Avoidance of Environmental Factors
Should we avoid environmental factors that may cause cancer?
Well, it can’t hurt!
When reviewing cancer as a whole, we can see that environmental factors likely have some effect on the development of cancer, but research reveals that there may be larger factors at play. However, each type of cancer has its own set of risk factors. If you are at risk for a specific type of cancer that you know has an environmental risk factor, it is prudent to avoid that risk factor.
In the United States, certain rules and regulation have been put into place to reduce workplace carcinogens in the workplace; this may not eliminate all carcinogens, but it definitely makes the workplace safer.
Avoiding carcinogens at home can be trickier; here are some tips:
- Quit smoking and avoid secondhand smoke exposure
- Testing basements for radon; if radon is detected, radon remediation should be performed
- Limiting sun exposure and use sunscreen
- Maintaining a healthy weight
In general, it is best to maintain a healthy lifestyle and reduce exposure to harmful environmental exposures as much as possible. If exposure to chemicals is suspected, it is recommended to wear a mask.
Cancer-causing substances in the environment. (2018, December 28). National Cancer Institute. https://www.cancer.gov/about-cancer/causes-prevention/risk/substances
Hantel, A. (2018, April 25). Environmental factors that cause cancer. Edward-Elmhurst Health. https://www.eehealth.org/blog/2018/04/environmental-factors-that-cause-cancer/
Israel, B. (2010, May 10). How many cancers are caused by the environment? Scientific American. https://www.scientificamerican.com/article/how-many-cancers-are-caused-by-the-environment/