Everything Life Sciences Grade 10

Figure 4.9: Graph showing correlation between smoking and lung cancer (courtesy NHI).

Questions:

1. In what year was the first incidence of lung cancer seen in male smokers?


2. How many years was this after the introduction of cigarettes?


3. In which year did the average number of cigarettes smoked per year reach a peak?


4. Approximate how many years it takes most male smokers to develop cancer? Clue:
   Compare the number of years seen between the two line graphs for 1000, 2000, 3000
   and 4000 cigarettes per year. Add the years together and divide by 4 to get the average
   time (in years) taken for smokers to develop cancer.


5. What can you say about the shape of the two graphs? Do they look similar or different?
   What does this mean?


6. What was the death rate from lung cancer in 1950? Express your answer as a percent-
   age and show your working.


7. Suggest a reason why the number of cigarettes smoked shows a decrease after 1945.

Activity: Research on cancer

Aim

To research and present information on one of the human cancers

Resources required

110 4.4. Cancer