Mercury was once thought safe to handle

Mercury was once thought to be safe to handle. Historically, the unique properties of mercury, including its liquid state at room temperature and its shiny appearance, led to its use in a variety of applications without a full understanding of the potential health risks.

Historical Uses and Handling of Mercury:

1. Medicine: Mercury was used in various medical treatments for centuries. It was believed to cure ailments and was used as a diuretic, laxative, and even an ointment for skin conditions. The term “quicksilver” was often used for mercury, and “mercurial” treatments, especially for syphilis, were common until the early 20th century.
2. Hats: The phrase “mad as a hatter” likely originates from the symptoms displayed by 18th and 19th-century hat makers who used mercuric nitrate in the felting process. Over time, prolonged exposure led to mercury poisoning, with symptoms including tremors, irritability, and mood swings.
3. Thermometers and Barometers: Mercury was widely used in scientific instruments like thermometers and barometers because of its consistent expansion and contraction with temperature and pressure changes.
4. Cosmetics: Mercury and its compounds were historically used in some cosmetics, including skin-lightening creams and mascara, until the health risks became more widely recognized.
5. Alchemical and Religious Practices: Mercury held a special place in various cultures due to its transformative nature, moving between solid amalgams and a liquid state.

Recognition of Mercury’s Toxicity:

While mercury was handled relatively freely in the past, symptoms of its toxicity were observed even in ancient times. As early as the first century AD, the famous Roman scholar Pliny the Elder noted that slaves involved in mercury mining exhibited severe mental and physical impairments. Over time, as scientific understanding evolved, the toxic effects of mercury became more widely acknowledged. By the late 19th and early 20th centuries, many of its more overt uses, especially in medicine, were phased out as the detrimental health effects became irrefutable.

Today, we recognize that even small amounts of mercury can be harmful, especially organic forms like methylmercury found in some fish. Consequently, the handling and disposal of mercury are subject to stringent regulations in many countries.