If you watch the news with any regularity, there are many, many things that we are told we must fear. Recently one of those things is the level of mercury in our bodies. From what I’ve read, this is a reasonable fear. Mercury, also called quicksilver, is the only common metal that is liquid at room temperature. It’s shiny and pretty and silvery. And toxic. One drop on the skin can be fatal. There are many physical symptoms of mercury poisoning, including neurological damage.

Mercury-element

These days we hear about the dangerously elevated levels of mercury in the fish we eat. The worst choices are those fish at the top of the food chain, like the tuna. These are the bigger fish with more tissue to store mercury, they live long enough to soak up more mercury into their bodies, and they eat smaller fish, consuming their mercury content.

Of course, we haven’t always known about mercury poisoning. I don’t know where or when or by whom, but it was decided that mercury could be used as a cure for various maladies and as an elixir for longer life. Mercury has been found in tombs from ancient China and Egypt, so this isn’t something new. It has been used as a treatment for syphilis, which in many ways was worse than the disease.

Mercury poisoning is also the origin of one of those phrases we use without thinking about it. “Mad as a hatter” is a real historical issue and did not originate with Lewis Carroll’s 1865 novel Alice’s Adventures in Wonderland. It was first mentioned in print in 1829, but it’s hard to tell how long it was in popular usage before then.

In the 18th and 19th centuries, hats were a common accessory, and many of them were made from felt. Industrial workers created felt by separating the skin and fur of small animals using mercury. This continued exposure to mercury produced symptoms such as emotional instability, memory loss, speech problems and loss of control of the body. These symptoms were so associated with hat-making that anyone displaying them was referred to as being “mad as a hatter”.

A worker on the assembly line of a Connecticut hat manufacturing plant. is working with colorizing agents as he produces felt hats. Note that the man is not wearing a protective breathing mask, gloves, or goggles. Working as he was with steam, and processed animal fur, airborne remnants of mercury nitrate could have easily been liberated, which he would then readily inhale. Inhalation of airborne mecury componds would have eventually lead to neurologic pathology, due to toxic heavy metal mercurialism. The image was published in the ”Public Health Bulletin”, No. 263, 1941, in an article entitled, ”Mercurialism and its Control in the Felt-Hat Industry". Photo: National Institute for Occupational Safety and Health (NIOSH)

A worker on the assembly line of a Connecticut hat manufacturing plant. is working with colorizing agents as he produces felt hats. Note that the man is not wearing a protective breathing mask, gloves, or goggles. Working as he was with steam, and processed animal fur, airborne remnants of mercury nitrate could have easily been liberated, which he would then readily inhale. Inhalation of airborne mecury componds would have eventually lead to neurologic pathology, due to toxic heavy metal mercurialism. The image was published in the ”Public Health Bulletin”, No. 263, 1941, in an article entitled, ”Mercurialism and its Control in the Felt-Hat Industry”. Photo: National Institute for Occupational Safety and Health (NIOSH)

But wait, there’s more. An alternative to mercury in curing felt was found in 1874, but the French and the English didn’t stop using mercury until the very late 19th or very early 20th centuries. Companies in the United States continued its use until 1941, the beginning of World War II, at which time mercury was needed for detonators for the war effort. Coincidence?

In any case, next time you think that your job is making you crazy…