Mercury (element) is used in thermometers, barometers, manometers, sphygmomanometers, float valves, mercury switches, mercury relays, fluorescent lamps and other 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 alternatives such as alcohol- or galinstan-filled glass thermometers and thermistor- or infrared-based electronic instruments. Likewise, mechanical pressure gauges and electronic strain gauge sensors have replaced mercury sphygmomanometers. Mercury remains in use in scientific research applications and in amalgam for dental restoration in some locales. It is also used in fluorescent lighting. Electricity passed through mercury vapor in a fluorescent
Sarah Liao annual air monitoring project. This program was designed to provide extensive background environmental data, which continued for five years. She then spent over seven years establishing and administering the program on Environmental Health & Safety at the University. Another area of work was the management of toxic and hazardous materials (chemical and biological) used in the University, including the procurement, storage, delivery, use, pre-disposal treatment and final disposal of these substances. At the same time she conducted large scale studies relating to workplace health and safety, hazard identification, risk assessment and environmental problems in a range of Hong Kong industries.