I can remember quite a few during my childhood. I had x-rays as part of the Upper GI series, the first of which was during second grade when I was first diagnosed with gastritis. My stomach has always been ultra-sensitive and I produced too much acid any time I was upset. I probably had GERD early on, too. This test was repeated a few times during my childhood and teen years. At fifteen I started having abdominal pain that was classic for gallbladder but nothing showed up on the various GI series that were done over the years for that. Not until my thirties, 22 years later.
I also had a few x-rays from the chiropractor, and more when I hurt my lower back at work in the mid-90s.
Once I had heart disease the x-rays multiplied. Every time I went in with chest pain, another x-ray, and that's maybe 8-9 times in the last decade, or more. I wasn't counting. Walking pneumonia, another x-ray. Three angiograms=more x-ray exposure. Two cortisone injections=fluoroscopy=x-ray exposure. Mammograms (4)...and a big one, CT scans--I've had five that I can remember off the top of my head. Oh yeah, dental x-rays, lost count. And various x-rays of my wrist, legs, knees, foot. Several of my neck.
Given that my many x-rays started young, I am apparently at increased risk of getting cancer late in life. (I'm kind of counting on heart disease to save me from that.)
In any event, you can see why I'm not at all worried about the tiny amounts of radiation that can make it here, despite the distance and wind, from Japan.
ETA: Also I've had a radioactive substance (thallium 201) injected into my bloodstream during 5 tests. The half life is 73.5 hours.