How much x-ray dosage is harmful?

The harmful effects of X-ray exposure depend on the dose and the duration of exposure. Generally, a dose above 100 millisieverts (mSv) is considered to increase the risk of cancer, while doses around 10 mSv carry a low but measurable risk. For perspective, a single chest X-ray typically delivers about 0.1 mSv, which is considered safe for most individuals. However, cumulative exposure over time can pose risks, so minimizing unnecessary X-rays is advisable.