All That Shines Is Not Gold, Sometimes It Poisons You

A broken mercury thermometer. Image taken by Tavo Romann via Wikimedia Commons.

When I was a child having a fever was common occurrence. Therefore, I was used to get my temperature checked and the thermometer always caught my attention. The thermometer we used to have was a mercury one. That shiny liquid metal always fascinated me so much that I could stare at it for hours, even though I could not understand how it worked despite many explanations from my parents.

Then one day the glass of the thermometer slightly cracked, and that shiny liquid metal got out. The first instinct was to go touch it. Fortunately, my parents stopped me before I could even try and gave me a very long on the dangers of mercury. Moral of the story: don’t touch it if you don’t want to get mercury poisoning.


The number 80

To understand what mercury poisoning is, the first step is to look at the element itself. Mercury is the 80th element of the periodic table that appears like a mirror-like dense liquid. It is used in numerous products from batteries, thermometers, cosmetics, switches, dental fillings and so on thanks to its chemical and physical characteristics. Such features include being the only liquid metal at room temperature, being a good electricity conductor, having high density and expanding when heated. It is found in three states: elemental (metallic), inorganic and as methylmercury.

In spite of its chemical characteristics and vast uses mercury is an incredibly toxic element that causes health issues when inhaled, ingested, absorbed by skin or injected due to its multiple forms. All living things contain mercury in small percentages, generally in the form of organic methylmercury, but fish are generally the ones having the most.

The element mercury. Image by Mrs Pugliano via Flickr.

How does mercury poisoning affect you?

The effects that mercury has on our bodies vary between the elements’ forms, the dosage, the method of exposure with methylmercury being the most dangerous one. Methylmercury and elemental mercury affect both the central and peripheral nervous systems, thus acting as neurotoxins. The former shows symptoms such impaired vision, walking, speech, uncoordinated movements and muscle weakness and a very specific feeling of having “pins and needles” in your extremities and around the mouth. The latter manifests with headaches, mood swings, memory issues, insomnia and usually tremors.

This is what makes mercury poisoning so incredibly scary in my opinion: the fact that its symptomatology is so vague that it can be hard to pinpoint the cause if we are unaware that we were exposed.


A harrowing history

Throughout history there have been many stories of mercury poisoning that show that one poisoning is not like the other.

I want to focus on Minamata Disaster and the case of Karen Wetterhahn to illustrate the dangers of mercury poisoning especially when methylmercury is involved.

During the 1950s wastewater from a chemical plant containing methylmercury was discharged in the waters of Minamata, a Japanese city in the Kumamoto Prefecture, contaminating the fish and shellfish of the bay. Ingesting the fish meant ingesting considerable amounts of mercury and for years the local population suffered the poisoning symptoms without knowing what was affecting them. This was until 1956 when finally the cause was determined to be mercury poisoning, but at that point was too late: in 36 years following the ecological disaster 1043 people would die out of 2252 diagnosed with Minamata disease.

Minamata Memorial: Dr. Naoko Ishii from the GEF pays tribute to the victims. Photo taken by the Global Environment Facility (GEF) via Flickr.

Another famous yet tragic case was that of scientist Karen Wetterhahn in 1996. In August of that same year she was working in her lab at Dartmouth College when she spilled a single drop of dimethylmercury on her gloved hand. She followed all the precautions during her experiment so after her work she went home without realising what had just happened.

For five months she suffered from loss of balance and impaired speech until she was finally diagnosed with mercury poisoning. Unfortunately, at the time it was not known that dimethylmercury could permeate latex gloves so no therapy was able to save Wetterhahn from the debilitating neurological disease that followed. She passed away 10 months after that mercury spill. Her case became famous for its tragic nature as well from what was learned from it on the dangers of dimethylmercury.

As we learn more and more on mercury and its toxic effects, the scientific community is working on reducing our reliance on it with the 2013 Minamata Convention being a step in the right way.

Perhaps at the time, when I saw that mercury spilling out of the thermometer, I did not understand well what was going on. However, I know now that all that shines is not gold and that sometimes it can poison you.

 References and further reading:

4 Responses to “All That Shines Is Not Gold, Sometimes It Poisons You”

  1. Alexandra-Maria Blejusca says:

    Thank you so much Misky! Sorry for the late reply, I checked for a week the comments to this post and nothing showed so I assumed no one commented, but I was wrong! I appreciate your kind words and your interest. Amalgam is a material composed of 50% elemental mercury and other metals, which is used as a dental filling. There are a lot of articled on this issue, but at the moment with the current scientific data it would seem that amalgam fillings are safe so they are still used and dentists generally do not advise to remove them. These kind of fillings have been used for almost 200 years and they re the cheapest material compared to others. I was surprised too, but I guess that there is no risk of mercury entering your bloodstream in this way.
    Thank you again for taking your time to read this!

  2. Alexandra-Maria Blejusca says:

    Thank you so much! I apologise for replying to you so late. Thanks for the kind words, I really appreciate that you liked my title, really the hardest part of writing this. Indeed mercury poisoning is a scary condition and the Minamata disaster is a truly a sad chapter. The chemical plant, Chisso Corporation, was from the start indicated as the cause of it, but despite public complaints it kept dumping mercury until ’68, ten years after they were asked to stop. The victims were compensated by the company and the government and Chisso Corporation still pays their medical bills 50 years later. This is such a sad story, but I felt it needed to be talked about as many corporations are too comfortable poisoning us and our planet and hiding when discovered. Thank you a lot for showing interest in this! 🙂

  3. helenap says:

    Hi Alexandra-Maria, thanks for the great read! Firstly, I love the title, it definitely made me click into this article. Also, reading those symptoms really does drive home how terrifying it would be to have mercury poisoning (I’m glad your parents saved you from playing with that thermometer’s mercury), and how difficult it would be to diagnose. Reading about the Minamata disaster is so tragic in that so many deaths could have been prevented. I wonder if the wastewater company knew about the effects of mercury and whether they compensated the victims and their families?

  4. Misky says:

    Hi Alexandra-Maria.

    This was such an interesting piece. I always knew that mercury was bad for you but didn’t know how exactly. Your explanation of the content was informative and easy to follow. Being that it is so dangerous, I wonder why we use mercury in dental fillings? My understanding is that something could easily go wrong and result in absorption of the mercury into our bodies, leading to all the adverse effects that you discussed