Typical radiation exposures for Americans
Per The National Council on Radiation Protection

On hour at ground zero = 1/2 mrem

Cosmic rays from space = 40 mrem at sea level per year

Radioactive minerals in rocks and soil = 55 mrems per year

Radioactivity from air, water, and food = anywhere from 20 to 400 mrem per year

About 22 mrem per chest X-ray and 900 mrem for whole-mouth dental X- rays

Smoking one pack of cigarettes a day for one year = 40 mrem

Miscellaneous such as watch dials and smoke detectors = 2 mrem per year

How to Get to Trinity Site

Trinity Site, where the world's first atomic bomb was exploded in 1945, is normally open to the public twice a year--on the first Saturday in April and October.