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
National Traffic and Motor Vehicle Safety Act initiated a campaign to prevent motor-vehicle-related injuries. In 1966, passage of the Highway Safety Act and the National Traffic and Motor Vehicle Safety Act authorized the federal government to set and regulate standards for motor vehicles and highways. The Highway Safety Act resulted in the national adoption of the Manual on Uniform Traffic Control Devices, while the National Traffic and Motor Vehicle Safety Act led to the national adoption of the Federal Motor Vehicle Safety Standards. High-Risk Populations Occupant-Protection Systems "Safety belts:" In response to legislation, highly visible law enforcement, and public education, rates of safety belt use nationwide had