Are ct scans really bad? my son had 2 head ct scans 6 months apart when he was 3 in the er. they said total msv for both scans was 3.8 msv. i worry about his cancer risk now. is it greatly increased?

We are all exposed to natural radiation. The average person receives a dose of about 3 mSv per year from natural radiation, which includes cosmic radiation from space. These natural "background doses" vary according to where you live. Simply put, the amount of radiation from a head CT is about the same as 8 months of natural background radiation that we are exposed to as part of our daily living.

The increase in cancer risk, if any is not measurable above the background risk. Your son can reduce the risk - You can reduce your risk of cancer by adopting healthy habits: Eat a mostly vegetarian diet, avoid alcohol, tobacco and street drugs, avoid excessive exposure to sun, get HPV vaccine, exercise 30 minutes each day, drink enough water so your urine is mostly colorless.