Is thyroid cancer is on the rise in the US? If so, is it due to Chernobyl?

Cancer of the thyroid, a butterfly-shaped gland in the neck that secretes hormones, is on the rise in this country, and is expected to strike 23,600 Americans this year and kill 1,460, said Dr. Michael Thun who heads epidemiological research for the American Cancer Society in Atlanta. Most of the increase is due to better detection, because of CT or ultrasound imaging that can find small tumors that would have been missed in the past.