In the United States in 2006, about 377 million diagnostic and interventional radiologic examinations and 18 million nuclear medicine examinations were performed.  Fred Mettler, Jr., from the University of New Mexico (USA) and US Representative to the United Nations Scientific Committee on Effects of Atomic Radiation, and colleagues have found that the per-capita annual effective radiation dose from medical procedures in the United States is among the highest in the world, estimated to have increased sixfold from about 0.5 mSv in 1980 to 3.0 mSv in 2006.  The United States accounts for about 12% of radiologic procedures and about one-half of nuclear medicine procedures performed worldwide. Worldwide it is estimated that for 2000–2007, 3.6 billion medical procedures with ionizing radiation (3.1 billion diagnostic radiologic, 0.5 billion dental, and 37 million nuclear medicine examinations) were performed annually, with the average annual per-capita effective dose approximately doubling in the past 10 to 15 years.