For Exercises 2.77 to 2.79, see page 101; and for 2.80, see page 102.
2.90 Do power lines cause cancer?
It has been suggested that electromagnetic fields of the kind present near power lines can cause leukemia in children. Experiments with children and power lines are not ethical. Careful studies have found no association between exposure to electromagnetic fields and childhood leukemia.13 Suggest several lurking variables that you would want information about in order to investigate the claim that living near power lines is associated with cancer.