Environmental radioactivity g) to that of the soil water (Bq ml). If the radioactivity is tightly bonded to by the minerals in the soil then less radioactivity can be absorbed by crops and grass growing in the soil. One dramatic source of man-made radioactivity is a nuclear weapons test. The glassy trinitite formed by the first atom bomb contains radioisotopes formed by neutron activation and nuclear fission. In addition some natural radioisotopes are present. A recent paper reports the levels of long-lived radioisotopes in the trinitite. The trinitite was formed from feldspar and quartz which were melted by the heat. Two samples
Barrel (unit) tankers. In the United States, the 42-US-gallon size of barrel as a unit of measure is largely confined to the oil industry, while different sizes of barrel are used in other industries. Nearly all other countries use the metric system. The abbreviations Mbbl and MMbbl refer to one thousand and one million barrels, respectively. These are derived from the Latin "mille" meaning "thousand". This is different from the SI convention where "M" stands for the Greek "mega", meaning "million". Outside of the oil industry, the unit Mbbl (megabarrel) can sometimes stand for one million barrels. The "b" may have been