outgassed from magma being trapped, for example by a lava dome. At the Earth's tectonic divergent boundaries where new crust is being created, helium and carbon dioxide are some of the volatiles being outgassed from mantle magma. Alpha decay of primordial radionuclides (and their decay products) produces the vast majority of the helium that continues to gas out of rocks on terrestrial planets. In a closed environment Outgassing can be significant if it collects in a closed environment where air is stagnant or recirculated. For example, new car smell consists of outgassed chemicals released by heat in a closed automobile. Even a nearly odorless material such as wood may build up a strong smell if kept in a closed box for months. There is some concern that plasticizers and solvents released from many industrial products, especially plastics, may be harmful to human health. Long-term exposure to solvent vapors can cause chronic solvent-induced encephalopathy (CSE). Outgassing toxic gases are of great concern in the design of submarines and space stations, which must have self-contained recirculated atmospheres. In construction The outgassing of small pockets of air near the surface of setting concrete can lead to permanent holes in the structure (called bugholes) that may compromise its structural integrity. See also Lake Nyos Disaster Materials for use in vacuum Volatile organic compound Comet References External links Outgassing Data for Selecting Spacecraft Materials Online (NASA database) ESA Outgassing Data for Spacecraft Materials according to ECSS-Q-70-02 Vacuum Gas technologies