Dental amalgam controversy emissions. The WHO also points out that amalgam separators, installed in the waste water lines of many dental offices, dramatically decrease the release of mercury into the public sewer system. In the United States, most dental practices are prohibited from disposing amalgam waste down the drain. Critics also point to cremation of dental fillings as an additional source of air pollution, contributing about 1% of total global emissions. It is the position of the FDI World Dental Federation as well as numerous dental associations and dental public health agencies worldwide that amalgam restorations are safe and effective. Numerous other organizations
Alchemy and chemistry in medieval Islam that have come down through the years were preserved as Arabic translations. In considering Islamic sciences as a distinct, local practice, it is important to define words such as "Arabic," "Islamic," "alchemy," and "chemistry." In order to gain a better grasp on the concepts discussed in this article, it is important to come to an understanding of what these terms mean historically. This may also help to clear up any misconceptions regarding the possible differences between alchemy and early chemistry in the context of medieval times. As A.I. Sabra writes in his article entitled, "Situating Arabic Science: Location versus Essence,"