A health survey followed adults for 10 years. The adults were grouped according to whether they smoked and whether they were aged 60 or over. The table shows the number of adults in every 1000 in each group who developed lung cancer during the survey.
| Factors present | Number of adults in every 1000 who developed lung cancer |
|---|---|
| Neither factor: non-smoker under 60 | 1 |
| Smoking only: smoker under 60 | 7 |
| Older age only: non-smoker aged 60 or over | 4 |
| Smoking and older age: smoker aged 60 or over | 30 |
Calculate how many more adults in every 1000 developed lung cancer among smokers under 60 than among non-smokers under 60.
Calculate how many more adults in every 1000 developed lung cancer among non-smokers aged 60 or over than among non-smokers under 60.
Use your answers to parts (a) and (b) to calculate the number of adults in every 1000 expected to develop lung cancer among smokers aged 60 or over if the effects of smoking and older age simply added together.
Compare the actual number for smokers aged 60 or over with your answer to part (c). What does this show about the combined effect of smoking and older age?
304 exam-style questions on AQA GCSE Biology 2.2 Animal tissues, organs and organ systems, covering 2.2.1 The human digestive system, 2.2.2 The heart and blood vessels, 2.2.3 Blood, 2.2.4 Coronary heart disease: a non-communicable disease, 2.2.5 Health issues, 2.2.6 The effect of lifestyle on some non-communicable diseases, and 2.2.7 Cancer. Each one has a worked solution and a mark scheme showing where the marks go.