Period 6 element devices though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alcohol-filled, galinstan-filled, digital, or thermistor-based instruments. It remains in use in scientific research applications and in amalgam material for dental restoration. It is used in lighting: electricity passed through mercury vapor in a phosphor tube produces short-wave ultraviolet light which then causes the phosphor to fluoresce, making visible light. Thallium is a chemical element with the symbol Tl and atomic number 81. This soft gray other metal resembles tin but discolors when exposed to air. The
Toxic waste Due to the hazards associated with toxic waste handling and disposal, communities often resist the siting of toxic waste landfills and other waste management facilities; however, determining where and how to dispose of waste is a necessary part of economic and environmental policy-making. The issue of handling toxic waste has become a global problem as international trade has arisen out of the increasing toxic byproducts produced with the transfer of them to less developed countries. In 1995, the United Nations Commission on Human Rights began to notice the illicit dumping of toxic waste and assigned a Special Rapporteur to examine