United States is very difficult to come by, and usage rates are not known. Burial vaults and liners are almost unheard of in China and Japan. Cremation is required in China, and is used in 90 percent of burials in Japan. They are also uncommon in Italy. In modern Italy, burial plots (either below-ground or in wall loculi) are re-used after a period of years, usually 10 to 25. At that time, most of the soft body parts have decomposed, and the bones are removed to an ossuary. In the United States, the use of burial vaults is also decreasing, caused by a sharp rise in the number of cremations. Whereas 36 percent of all deceased were cremated in the United States in 2008, the National Association of Funeral Directors forecast this to rise to 46 percent by 2015 and 59 percent by 2025. Jewish law does not bar the use of burial vaults or liners, and their use is permitted where law or a cemetery requires them. But Morrison David Bial argues that burial vaults are antithetical to traditional Judaism, in part because they deny the reality of death (e.g., inhibit decomposition of the body) and in part because they are ostentatious and undercut the equality of all people at death. Islamic law requires only that the body be washed, anointed, and wrapped in linen for burial. Funerals must be kept simple, and no ostentation is allowed. Preferably, the body should be buried without coffin or burial vault, although such is permitted if required by law. Generally, Muslims prefer to have separate cemeteries due to the specific preference for burial without coffin or vault. Criticisms Burial vaults and liners do not decompose, and have been criticized as being environmentally unfriendly. Burial vaults and liners consumed more than of steel and more than of reinforced concrete in 2009. A burial vault or liner is not the only solution to settling earth over the grave. Traditional burials with a casket leave a larger void and thus create more settlement when the casket decomposes or collapses. Natural or "green" burials do not use a casket, which means only minimal settling. In either case, the cemetery can remedy sunken graves by filling in the settled area. References Inline citations General references Death customs