enivronmental impacts on cancer

Environmental Impacts on Cancer Today

What impact do environmental factors have on cancer rates? 

Environmental factors can damage DNA, changing the way our cells function and contributing to rising cancer rates. In a society awash in carcinogens, some of these environmental carcinogens are more obvious than others. Some are subtle. Fortunately, many of these environmental factors can be avoided.

The most common carcinogens

The National Toxicology Program’s 14th Report on Carcinogens listed the substances that were most likely to cause cancer. Of note: just because a person is exposed to a carcinogen does not mean that they will develop cancer. Other factors come into play, such as the length of time the person is exposed, as well as that person’s genetic background.

The report found the following substances likely linked to certain cancers:

  • Aflatoxins
  • Aristolochic acids
  • Arsenic
  • Asbestos
  • Benzene
  • Benzidine
  • Beryllium
  • 1,3-Butadiene
  • Cadmium
  • Coal tar and coal tar pitch
  • Coke oven emissions
  • Crystalline silica
  • Erionite
  • Ethylene oxide
  • Formaldehyde
  • Hexavalent chromium compounds
  • Household combustion of coal
  • Mineral oils
  • Nickel compounds
  • Radon
  • Secondhand smoke
  • Soot
  • Strong inorganic acid mists containing sulfuric acids
  • Thorium
  • Trichloroethylene
  • Vinyl chloride
  • Wood dust

Measuring the impact 

Experts are still measuring the contribution of environmental factors to the development of cancer. In past years, researchers estimated that environmental impacts factored into about 6% of cancers. Pinning down a precise number, however, is difficult.

In a 2022 workshop hosted by the National Institutes of Environmental Health Sciences,  researchers explored the role of environmental factors in development of breast cancer. Workshop co-chair Alexandra White, Ph.D., head of the institute’s Environment and Cancer Epidemiology Group, summed up the difficulty of the study.

“We know that single exposure analysis does not accurately reflect real-life exposure patterns because people are exposed to multiple chemicals simultaneously,” said White. “Analyzing one chemical exposure at a time can result in an underestimation of risk.”

“Scientists most likely will never be able to tease out the true role of environmental contaminants,” added a report by the President’s Cancer Panel, “because environmental exposures, genetics and lifestyle seem to all intertwine.”

Related: Breast Cancer: Exploring Current Detection, Screening, and Treatment Strategies

A mystery percentage

For example, scientists understand that smoking contributes to approximately 30% of cancer deaths. Obesity, diet, and lack of exercise contribute to another 30%. The remaining percentage is tied to . . . what?

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.

Consider a person who develops lung cancer. They smoke, but they also live in an area with high air pollution. This person’s smoking habit is a critical factor — after all, 90% of lung cancers occur in smokers. Pollution exposure nevertheless remains a contributing factor.

Avoiding environmental carcinogens

While some exposure to environmental pollutants is inevitable, individuals can take steps to reduce their risk of certain cancers. In the United States, regulations mandate conditions that automatically reduce carcinogens in the workplace. Though this may not eliminate all carcinogens, it does help contribute to overall workplace safety.

Related: Breast Cancer: Contemporary Rehabilitation Strategies

Avoiding carcinogens at home can be trickier. Here are some tips:

  • Quit smoking
  • Avoid secondhand smoke exposure
  • Test basements for radon
  • If radon is detected, perform radon remediation
  • Limit sun exposure
  • Use sunscreen
  • Maintain a healthy weight


  1. Cancer-causing substances in the environment. (2018, December 28). National Cancer Institute. https://www.cancer.gov/about-cancer/causes-prevention/risk/substances
  2. 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/