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 the goods once they become ineffective or broken. In the US, the Environmental Protection Agency (EPA) and state environmental agencies develop and enforce regulations on the storage, treatment and disposal of hazardous waste. The EPA requires that toxic waste be handled with special precautions and be disposed of in designated facilities around the country. Also, many US cities have collection days where household toxic waste is gathered. Some materials that may not be accepted at regular landfills are ammunition, commercially generated waste, explosives/shock sensitive items, hypodermic needles/syringes, medical waste, radioactive materials, and smoke detectors. Toxic wastes often contain carcinogens, and