Directions: 

Interact with the AI below. Show it what you learned during yesterday's lesson! 

Liver cancer cases in East Valley, Ohio, have been rising since a train derailment spilled harmful chemicals. Some of these chemicals, like vinyl chloride, can be dangerous to humans. Your task is to investigate whether the derailment is linked to the increase in cancer cases. How might people have been exposed to these chemicals? What evidence would show a connection? What other information would scientists need to be sure? Use your research to explain whether the chemicals from the derailment could be causing the higher cancer rates. 

When Mitosis Breaks Down: Cancer
Cancer starts when mutations (DNA changes) disrupt the genes that regulate mitosis. Cells ignore checkpoint signals, divide uncontrollably, and form tumors. Dangerous malignant tumors can spread (metastasize) to other organs.

What Causes Cancer?
Most cancers result from a mix of genetic and environmental factors:

• Inherited mutations: Some people are born with DNA errors that increase cancer risk.

• Viruses: HPV, for example, can cause cervical cancer.

• Carcinogens: Harmful substances that damage DNA. Common examples include:

  • Tobacco smoke (linked to lung cancer).

  • UV radiation from the sun (causes skin cancer).

  • Vinyl chloride, a chemical used in plastics manufacturing.

Vinyl Chloride and Liver Cancer: A Toxic Connection
Vinyl chloride is a carcinogen that factory workers might inhale when making PVC plastics. Over time, this chemical damages liver cells by mutating genes that control mitosis. One rare but deadly result is liver cancer (hepatic angiosarcoma). The mutations caused by vinyl chloride "turn off" genes that normally stop cells from dividing too much. Without these brakes, liver cells multiply wildly, forming tumors.

Reducing Cancer Risks
While not all cancers are preventable, you can lower your risk:

• Avoid tobacco and limit alcohol.

• Use sunscreen and protective clothing outdoors.

• Follow safety guidelines around chemicals (e.g., masks or gloves in labs).

• Governments regulate carcinogens like vinyl chloride to reduce public exposure.