You know that you are supposed to be careful when disposing of mercury. But why? And what if it comes in such a tiny amount as what is in a thermometer?
Mercury is a toxic element that has confounded and enticed people since its discovery. The element 80, with the abbreviation Hg, has long been associated with speed. This is because, at room temperatures, it holds together well and glides almost without friction over a surface.
This speed, combined with its color, earned it the nickname “quicksilver.”
Because even water would not stick to it, a popular use for mercury in the past was to treat felt hats. Hatters would rub the element onto the felt surface, making the hat virtually waterproof.
Over time, though, the effect of daily interaction was very pronounced on hatters. They tended to suffer from mental illness or “lunacy” at a high rate, which was the basis for the term “mad as a hatter.” Mercury was the culprit.
Mercury in thermometers
Mercury was also very responsive to changes in temperature. If it got hotter, it would expand. Cooler, it would contract. It became the most common ingredient in home thermometers, as a reliable and sensitive gage of temperature.
However, as the EPA and global environmental groups came to realize, mercury was causing a host of other illnesses in people.
Worse yet, when dumped in the environment, mercury did not break down.
Instead, it steadily made its way to water, remaining in its original form. There it sat until ingested by fish, or the things that fish ate. Then people ate those fishes. As our testing became more sensitive, we came to realize this mercury in the environment threatened our health. This led to a ban on the use of mercury in 2008, with the goal of not using it in the US and limiting its use around the world.
What if I happen across some mercury?
Despite the ban, mercury is still around us. It can be found in an old home science kit, or a thermometer that your mom has used for decades.
If you find mercury in any form while you are cleaning out the basement or a parent’s house, including a trace amount in an old thermometer, there are specific rules for disposal.
Your community likely offers one or more ways to safely dispose of this dangerous element. A quick guide from the EPA is available here: https://www.epa.gov/mercury/storing-transporting-and-disposing-mercury
A search in your phone book or online should reveal a local drop-off site for your hazardous material.