Uploaded August 2018 | Updated September 2026, 8 hours ago
From Percival Pott's discovery of scrotal cancer among English chimney sweeps in 1775 to 1895 reports of bladder cancers in workers in a German synthetic dye factory, we’ve long known that occupational or environmental exposures could cause cancer. In 1915, researchers at Tokyo University, induced cancer in lab animals for the first time by applying coal tar to rabbit skin. Today we recognize and avoid many specific substances that cause cancer: coal tars and their derivatives (like benzene), some hydrocarbons, aniline (a substance used to make dyes), asbestos, and many others. Ionizing radiation from a variety of sources, including the sun, is also known to cause cancer. This clip is from the 1950 film, Challenge: science against cancer, from the Medical Film Institute and available from the National Library of Medicine’s history collection. This film attempts to explain why researchers are having a difficult time discovering the causes and cures for cancer. It begins with an overview of the birth of man from one cell and generally explores the complexity of the human body. It shows the isolation and testing of cancer cells and explains the effects of heredity and environment on normal cells. It explains the difficulties of tracing several generations for heredity research and the multitude of chemicals, etc. which affect cells and turn them cancerous. The World Health Organization’s International Agency for Research on Cancer (IARC) has identified more than 100 chemical, physical, and biological carcinogens. Many of these associations were recognized long before scientists understood much about how cancer develops. Today, research is discovering new carcinogens, explaining how they cause cancer, and providing insight into ways to prevent cancer. By the middle of the 20th century, scientists had the instruments they needed to work on some of the complex problems of chemistry and biology that remained unsolved. James Watson and Francis Crick, who received a Nobel Prize in 1962 for their work, had discovered the exact chemical structure of DNA, the basic material in genes. DNA was found to be the basis of the genetic code that gives orders to all cells. After learning how to translate this code, scientists were able to understand how genes worked and how they could be damaged by mutations (changes or mistakes in genes). These modern techniques of chemistry and biology answered many complex questions about cancer. For much more on occupational and environmental cancer and its prevention, read the NIEHS publication, Cancer and the Environment, available at niehs.nih.gov/health/materials/cancer_and_the_environment_508.pdf.
From Percival Pott's discovery of scrotal cancer among English chimney sweeps in 1775 to 1895 reports of bladder cancers in workers in a German synthetic dye factory, we’ve long known that occupational or environmental exposures could cause cancer. In 1915, researchers at Tokyo University, induced cancer in lab animals for the first time by applying coal tar to rabbit skin. Today we recognize and avoid many specific substances that cause cancer: coal tars and their derivatives (like benzene), some hydrocarbons, aniline (a substance used to make dyes), asbestos, and many others. Ionizing radiation from a variety of sources, including the sun, is also known to cause cancer. This clip is from the 1950 film, Challenge: science against cancer, from the Medical Film Institute and available from the National Library of Medicine’s history collection. This film attempts to explain why researchers are having a difficult time discovering the causes and cures for cancer. It begins with an overview of the birth of man from one cell and generally explores the complexity of the human body. It shows the isolation and testing of cancer cells and explains the effects of heredity and environment on normal cells. It explains the difficulties of tracing several generations for heredity research and the multitude of chemicals, etc. which affect cells and turn them cancerous. The World Health Organization’s International Agency for Research on Cancer (IARC) has identified more than 100 chemical, physical, and biological carcinogens. Many of these associations were recognized long before scientists understood much about how cancer develops. Today, research is discovering new carcinogens, explaining how they cause cancer, and providing insight into ways to prevent cancer. By the middle of the 20th century, scientists had the instruments they needed to work on some of the complex problems of chemistry and biology that remained unsolved. James Watson and Francis Crick, who received a Nobel Prize in 1962 for their work, had discovered the exact chemical structure of DNA, the basic material in genes. DNA was found to be the basis of the genetic code that gives orders to all cells. After learning how to translate this code, scientists were able to understand how genes worked and how they could be damaged by mutations (changes or mistakes in genes). These modern techniques of chemistry and biology answered many complex questions about cancer. For much more on occupational and environmental cancer and its prevention, read the NIEHS publication, Cancer and the Environment, available at niehs.nih.gov/health/materials/cancer_and_the_environment_508.pdf.
