Radiation effects from the Fukushima Daiichi nuclear disaster PBq of caesium-137. In May 2012, TEPCO reported that at least 900 PBq had been released "into the atmosphere in March last year [2011] alone" up from previous estimates of 360-370 PBq total. The primary releases of radioactive nuclides have been iodine and caesium; strontium and plutonium have also been found. These elements have been released into the air via steam; and into the water leaking into groundwater or the ocean. The expert who prepared a frequently cited Austrian Meteorological Service report asserted that the "Chernobyl accident emitted much more radioactivity and a wider diversity of radioactive elements than Fukushima
Caesium-137 in flow meters, thickness gauges, moisture-density gauges (for density readings, with americium-241/beryllium providing the moisture reading), and in gamma ray well logging devices. Caesium-137 is not widely used for industrial radiography because it is quite chemically reactive, and hence difficult to handle. The salts of caesium are also soluble in water, and this complicates the safe handling of caesium. Cobalt-60, , is preferred for radiography, since it is chemically a rather nonreactive metal and produces higher energy gamma-ray photons. As a purely man-made isotope, caesium-137 has been used to date wine and detect counterfeits and as a relative-dating material for