By how much does smoking increase the risk of asbestos-related lung cancer?

By how much does smoking increase the risk of asbestos-related lung cancer?

• A. About 2 times
• B. About 10 times
• C. Over 50 times
• D. Over 100 times

Answer: (C)

The important idea here is the strong, multiplicative interaction between smoking and asbestos exposure. When both factors are present, the risk of asbestos-related lung cancer is not just added on top of each other; they amplify each other in a way that makes the overall risk far higher than either factor alone. Epidemiology shows that people who both smoke and are exposed to asbestos have a dramatically higher risk—roughly fiftyfold or more—compared with someone with no exposure and who does not smoke. In other words, the combination creates a much larger cancer risk than simply adding the two risks together, which is why the best answer is that smoking increases risk by over 50 times. This is why smoking cessation is especially important for individuals with asbestos exposure: the synergy between these two factors drives a much higher cancer risk than either factor alone.

The important idea here is the strong, multiplicative interaction between smoking and asbestos exposure. When both factors are present, the risk of asbestos-related lung cancer is not just added on top of each other; they amplify each other in a way that makes the overall risk far higher than either factor alone.

Epidemiology shows that people who both smoke and are exposed to asbestos have a dramatically higher risk—roughly fiftyfold or more—compared with someone with no exposure and who does not smoke. In other words, the combination creates a much larger cancer risk than simply adding the two risks together, which is why the best answer is that smoking increases risk by over 50 times.

This is why smoking cessation is especially important for individuals with asbestos exposure: the synergy between these two factors drives a much higher cancer risk than either factor alone.