Question 7.69
39. Could the magnetic fields from power lines cause leukemia in children? Investigators who wanted to explore this question spent five years and $5 million comparing 638 children who had leukemia and 620 who did not. They went into the homes and actually measured the magnetic fields in the children’s bedrooms, in other rooms, and at the front door. They recorded facts about nearby power lines for the family home, as well as for the mother’s residence when she was pregnant. Result: They found no evidence of more than a chance connection between magnetic fields and childhood leukemia. Explain carefully why this study is not an experiment, and state what kind of study it is.
39.
No treatment was imposed on the subjects. This observational study collected detailed information about the subjects but made no attempt to influence them. This is a retrospective study since the children were broken into two groups at the start of the study, those with leukemia and those who did not have leukemia, and then it looked for possible links between magnetic fields in the children’s environment and the illness.