Sir Percival Pott, a London physician in 1775, felt sorry for chimney sweeps. They were child laborers who Pott thought were treated cruelly. They were poorly fed, barely clothed, and forced to ascend into sooty chimneys. Too often, Pott saw they were “bruised, burned, and almost suffocated.”

In his practice at St. Bartholomew’s Hospital, Pott observed a tragic trend among the young chimney sweeps. Many of them suffered from scrotal cancer by the time they reached puberty. Pott connected the cancer to the chimney soot, which scientists would one day identify as a carcinogen.

Pott’s observation was one of the first instances in which a human-made carcinogen (sooty chimneys) was tied to cancer. Since his time, scientists have come to better understand how human-made carcinogens can contribute to cancer. Problematically, people often don’t know or understand the risks associated with exposure to carcinogens. 

Carcinogens Cause Cancer

The National Cancer Institute describes a carcinogen in simple terms — “any substance that causes cancer.”

In some instances, the carcinogen occurs naturally in the environment. The International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO), organizes carcinogens into multiple groups based on the likelihood they can cause cancer. Solar radiation is an example of a naturally occurring carcinogen.

Other examples of naturally occurring carcinogens include radium, a chemical element known to cause cancer, and erionite, a mineral found in volcanic ash.

Read More: What Genetic Tests Really Say About Your Cancer Risk

Humanmade Carcinogens

Human-made carcinogens range from toxins that occur in production processes (like leather dust) to pollutants that occur as a result of industrialization (like engine exhaust). Carcinogens have also been tied to food items such as processed meats, which the IARC deemed carcinogenic in 2015.

The IARC also lists certain professions like firefighting, hair styling, and house painting to be a group one carcinogen, meaning it’s a known carcinogenic to humans. But that doesn’t mean everyone who becomes a firefighter is doomed to develop cancer. Similarly, not everyone who eats lunch meat is going to develop cancer.

However, there are some instances in which human-made carcinogens have been proven to be highly hazardous to those who come in contact with them.

Read More: Why Is It So Hard to Find a Cure for Cancer?

Hazardous Materials

According to an August 2022 study in The Lancet, 44.4 percent of cancers were associated with an avoidable risk factor. Tobacco and alcohol use topped the list for risk-attributable cancer deaths. The researchers also saw cancers related to “metabolic risk factors,” meaning having a high body-mass index (BMI) or high blood sugar levels. Other factors included exposure to air pollution, asbestos, and second-hand smoke. 

The study compared results from 2010 and 2019, and researchers were able to analyze the differences between the decades. Secondhand smoke, for example, wasn’t listed as one of the top ten leading risk factors in 2010. But it moved into the tenth spot in 2019, even though the researchers noted there have been global efforts to tax and regulate smoking. 

Snuffing Out Smoking

Cigarettes don’t just contain tobacco. They also include carcinogens such as arsenic, benzene, formaldehyde, and lead. The result? Puffs of tobacco smoke contain thousands of chemicals, including 70 that are known carcinogens, which explains why both smoking and second-hand smoke are in the current list of top 10 contributors to cancer deaths.

Tobacco use is declining. As of January 2024, the WHO estimated that 1.25 billion adults smoked. That meant about one in five adults used tobacco, which was a decrease from 2000 when one in three adults used tobacco.  

Tapering Tanning

Similar to anti-smoking campaigns, there have been efforts to regulate tanning beds after they were declared a carcinogen. According to a November 2022 study, Current Oncology, the epidemiology continues to show a dose-response relationship between tanning beds and skin cancer, meaning the more a person tans, the more likely they are to develop skin cancer.  

Tanning became common when tanning salons first opened in the early 1980s, targeting women and teenage girls. This led to what one researcher described as an “insidious epidemic of tanning bed use among adolescent girls and young women.” By 2009, 37 percent of 17-year-old white females were tanning.

After the WHO declared tanning beds a carcinogen in 2009, some U.S. states enacted strict age restrictions. Public health campaigns also began to warn against tanning. In states with age restrictions, tanning dropped 47 percent among adolescent girls.

Combating Coal Dust 

Scientists have long understood that coal miners suffer from lung affiliations due to their exposure to toxins in coal dust. In 2023, a study published in Occupational & Environmental Medicine examined data from the National Death Index for 235,550 coal miners who died between 1979 and 2017. The study was the largest analysis of coal miners’ cause of mortality.

The study found that compared to non-miners of a similar demographic, coal miners had “significantly increased odds” of developing lung cancer, chronic obstructive pulmonary disease (COPD), or coal workers’ pneumoconiosis (CWP).

The research team also considered when the miners were born and if modern miners were more likely to develop a respiratory illness than their predecessors. They found that miners born after 1940 were eight times more likely to die from a respiratory illness than the earlier generations. 

The authors also noted that coal miners were exposed to other carcinogens such as asbestos, diesel exhaust, radon, and silica. Miners across all generations were more likely to die from lung cancer compared to the rest of the population. 

The authors recommended that miners have access to early lung cancer screening so the disease can be detected and treated while still in the early stages.

Read More: Lung Cancer Is The Deadliest, Screening Could Save Many Lives

Article Sources

Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:

Emilie Lucchesi has written for some of the country’s largest newspapers, including The New York Times, Chicago Tribune and Los Angeles Times. She holds a bachelor’s degree in journalism from the University of Missouri and an MA from DePaul University. She also holds a Ph.D. in communication from the University of Illinois-Chicago with an emphasis on media framing, message construction and stigma communication. Emilie has authored three nonfiction books. Her third, “A Light in the Dark: Surviving More Than Ted Bundy,” releases October 3, 2023 from Chicago Review Press and is co-authored with survivor Kathy Kleiner Rubin.