Liberal Arts Blog — Arsenic I — Toxicity, Groundwater Contamination, Industrial Uses, Biological Function
Liberal Arts Blog — Wednesday is the Joy of Science, Engineering, and Technology Day
Today’s Topic — Arsenic I — toxicity, groundwater contamination, industrial uses, biological function
Element 33 in the Periodic Table is arsenic, the legendary poison. Roman Emperor Nero used arsenic to get rid of his 13 year old stepbrother Britannicus. The Medicis and the Borgias made similar use of the toxin. But arsenic is also an essential trace element for birds and other animals and has many industrial uses (notably in the manufacture of pesticides and semiconductor).
The greatest threat to public health from arsenic is contaminated groundwater. “Inorganic arsenic is naturally present at high levels in the groundwater of a number of countries, including Argentina, Bangladesh, Cambodia, Chile, China, India, Mexico, Pakistan, the United States of America and Viet Nam.”
What makes arsenic so toxic? why does is appear to be an essential trace element in some animals?
What scientists pioneered our understanding of it? Today, a closer look at element 33.
Every day is a great day to marvel at the mysteries of the Periodic Table! The intricacies of each and how they combine with others to make things like us, non-stick frying pans, and ozone-destroying chlorofluorocarbons!
This is the 28th in a series on the marvels and mysteries of the Periodic Table.
We began with phosphorus, then nitrogen, potassium, sodium, calcium, oxygen, hydrogen, chlorine, carbon, copper, iron, and lead. Then we proceeded to silicon, zinc, magnesium, gold, platinum. Then a break to discuss the eclipse. Then a return with molybdenum, helium, Iodine, manganese, lithium, fluorine, titanium, and most recently, selenium.
What do you know about arsenic that the rest of us might delight to learn?
Experts — please chime in. Correct, elaborate, elucidate.
ITS TOXICITY IS BASED ON ITS SIMILARITY TO PHOSPHORUS — THE LOCK AND KEY ANALOGY
1. “Your can think of enzymes and the chemicals they act upon as locks and keys. Arsenic is like a key that is not cut correctly — it it goes into a lock on a door, not only will it not unlock that door, it can get jammed in there and prevent another key (phosphorus) from getting in to unlock that door. In this way, arsenic can block a lot of vital chemical pathways.”
2. “By chemically jamming cellular locks, arsenic can harm nearly every orgain the human body. Large dose can lead to symptoms including vomiting, diarrhea, dehydration, shock, abnormal heart rhythms and multiple-organ failure, which may ultimately result in death.”
3. “Individual susceptibility to arsenic poisoning varies widely; saome people can tolerate doses of the elment that would kill others.”
NB: “Despite its deadly potential, arsenic poisoning is treatable if caught early… a key medicine is dimercaprol, which was developed by British scientists during
World War II as an antidote to arsenic-based chemical weapons.”
USES OF ARSENIC — from medicine to pesticides, wood preservation, glass production, semiconductors
1. “In 1909, German chemist and Nobel Prize winner Paul Ehrlich and his colleagues developed an arsenic-loaded compound called Salvarsan, which became the first effective treatment for syphilis….The principle behind how Salvarsan works, wherein a drug seeks out and destroys diseases cells, eventually found use in chemotherapy.”
2. “Arsenic is used industrially as an alloying agent, as well as in the processing of glass, pigments, textiles, paper, metal adhesives, wood preservatives and ammunition. Arsenic is also used in the hide tanning process and, to a limited extent, in pesticides, feed additives and pharmaceuticals.”
3. “Arsenic is a fundamental building block for semiconductor devices. It’s primarily used in conjunction with gallium to produce gallium arsenide (GaAs) wafers, which are used in a variety of commercial and military applications, including communications, lasers, and light-emitting diodes.”
NB: “Arsenic is a common n-type dopant in semiconductor electronic devices.”
WAS NAPOLEON KILLED BY ARSENIC POISONING? DELIBERATE OR ACCIDENTAL (FROM HIS WALL PAPER)? (see Emsley, below)
1. “Accidental arsenic poisoning was a threat in the nineteenth century when wallpapers were often printed with arsenic dyes such as Scheele’s green and Paris green (also known as emerald green, which are copper arsenates.” (Emsley)
2. “When walls became damp they could give off deadly methylarsine gas due to the action of moulds growing on them. Breathing in the air in such rooms for any length of timie, as in a bedroom, was capable of producing chronic arsenic poisoning.”
3. “Such a fate might have befallen Napoleon when he was confined to the damp island of St. Helena after the battle of Waterloo. High levels of arsenic were detected in his hair when they were analyzed by neutron activation analysis, showing he had been exposed to the element whether this was deliberate, or through taking Dr. Fowler’s solution, or from his wallpaper is not known. The last of these possibilities was confirmed when a sample of wallpaper from Longwood House, his home on St. Helena, was found in a scrapbook in the 1980s and was analyzed; the green pattern on it was an arsenic pigment.”
NB: In the final link below, Dr. Howard Markel of the University of Michigan and the PBS News Hour takes a more skeptical view of the arsenic poisoning theory.
https://www.pbs.org/newshour/health/how-napoleons-death-in-exile-became-a-controversial-mystery
John Emsley, Nature’s Building Blocks: An A-Z Guide to the elements — highly recommended. Definitely my favorite chemistry book of all time.
QUOTE OF THE MONTH
“Make your own Bible. Select and collect all the words and sentences that in all your readings have been to you like the blast of a trumpet.”
- Ralph Waldo Emerson
My spin — then periodically review, re-rank, and exchange your list with those you love. I call this the “Orion Exchange” because seven is about as many as any human can digest at a time. Game?
A LINK TO THE LAST FOUR YEARS OF POSTS ORGANIZED BY THEME:
PDF with headlines — Google Drive
ATTACHMENT BELOW -
#1 A graphic guide to justice (9 metaphors on one page).
#2 “39 Songs, Prayers, and Poems: the Keys to the Hearts of Seven Billion People” — Adams House Senior Common Room Presentation, (11/17/20)
NB: Palestine Orion (Decision) — let’s exchange Orions, let’s find Rumi’s field (“Beyond all ideas of right and wrong, there is a field. Meet me there” Rumi, 13 century Persian Sufi mystic)
YOUR TURN
Please share the coolest thing you learned this week related to science, engineering, or technology.
Or, even better, the coolest or most important thing you learned in your life related to science and engineering.
This is your chance to make someone else’s day. Or to cement in your mind something that you might otherwise forget. Or to think more deeply about something dear to your heart. Continuity is key to depth of thought.
