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Irish Teeth Reveal the Chemical Signature of the Great Famine

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The Custom House Famine Memorial in Dublin. Image credit: William Murphy via Flickr // CC BY-SA 2.0

The Great Famine in Ireland, one of the worst starvations in human history, lasted from 1845 to 1852. Sometimes called the “Irish Potato Famine” due to a disease that ravaged the crop that many Irish diets were based on, this period saw the population of Ireland decrease by about one-quarter. Around 1 million people died from starvation and other diseases, while another million or so left Ireland for new lives elsewhere in Europe and the U.S. While historically, the famine is well known, research into its physical effects is a comparatively new topic in archaeology.

A novel study by Julia Beaumont of the University of Bradford and Janet Montgomery of Durham University, published recently in PLOS One, tackles the question of how to identify famine and other chronic stress from specific skeletons. They focus their analysis on human remains from the Kilkenny Union Workhouse in southeast Ireland, just one of the many workhouses that sprang up after 1838, when a law was passed to help “remedy” poverty by institutionalizing the poor and making them work long hours. Individuals and entire families would enter the workhouse, which was segregated by age and sex, overcrowded, and full of sick people.

At least 970 people were buried in mass graves at Kilkenny, in unconsecrated ground. The researchers focused on the teeth of 20 of them, representing a cross-section of age and sex. Six had died before age 9.

The failure of the potato crop shortly after the emergence of Irish workhouses meant reduced food for the poor and, as a consequence, a significant amount of sickness and death among this vulnerable population. Although the government was slow to respond to the food crisis, eventually it began to import corn from America to feed the poor. And this introduction of corn is particularly helpful archaeologically, because corn's chemical composition is very different from that of potatoes and Old World grains. Archaeologists who analyze human bones and teeth can see the dramatic differences in corn-based and wheat-based diets by measuring the ratio of the two carbon isotopes in the skeleton.

The first important finding from Beaumont and Montgomery’s study is that, for many of the 20 people they analyzed, they could see the carbon isotopes rising after the start of the Great Famine. By micro-sampling the dentine portion of teeth at various stages of formation, they show an increase in corn consumption through time that correlates well with historical information about diet.

But their second finding is even more intriguing: Even as carbon isotopes increased, the nitrogen isotopes decreased. Archaeologists use nitrogen isotopes to understand the amount of protein in a diet. If you are a carnivore and eat food high on the food chain, you have a higher nitrogen isotope signature than if you are a vegetarian. The drop in nitrogen isotopes the researchers found in the teeth that occurred after the introduction of corn does not track with historical records; there is no known change in the protein that the poor were eating at this time.

Beaumont and Montgomery argue that the change in isotopes reflects a cycle of starvation. The high nitrogen values prior to the introduction of corn don't suggest these people had a lot of meat protein to eat. Instead, these isotopes most likely indicate that their bodies, starving, were in a sense eating themselves, by recycling their own protein and fat. When the Kilkenny workers started eating corn, their nitrogen values dropped as their bodies were able to use corn for survival.

The researchers say the “famine pattern” in this historic Irish population is therefore one of average carbon values paired with high nitrogen values, followed by higher carbon and lower nitrogen values when corn is introduced to stave off starvation.

Beaumont and Montgomery see this pattern in the teeth of children who died in the workhouse during the famine, but also in the teeth of some of the adults. Since teeth form during childhood, this finding suggests that the adults suffered from—and overcame—one or more periods of chronic stress prior to the Great Famine. These stresses might have been caused by famine, but prolonged disease can leave similar isotopic traces, so they can't say for sure the adults experienced multiple periods of starvation.

This research comes at a time when micro-sampling of teeth is becoming a popular technique in archaeology. A recent study by researchers at McMaster University, for example, micro-sampled tooth dentine to look at cases of rickets, a deficiency of vitamin D.

Beaumont has plans to expand this research and to correlate this new methodology with other techniques useful for finding evidence of famine. “I have some teeth from other populations with nutritional deficiencies which I am micro-sampling to try to achieve a resolution that matches the physical signs, such as enamel hypoplasias," Beaumont tells mental_floss. (An enamel hypoplasia is a defect in tooth enamel.) "I want to work with others in the field to investigate the histology.”

Studies into ancient diets are not just useful for archaeologists; sadly, starvation and famine are not things of the past. Their findings can also be used by forensic anthropologists investigating recent deaths, especially, as the researchers write, “of populations and individuals for whom nutritional stress may have contributed to their death.” This work may prove critically important in the future for solving forensic cases of fatally malnourished children.

As for the skeletal remains of the 20 people studied—they were all re-interred at the Famine Memorial Garden in Kilkenny.

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11-Year-Old Creates a Better Way to Test for Lead in Water
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In the wake of the water crisis in Flint, Michigan, a Colorado middle schooler has invented a better way to test lead levels in water, as The Cut reports.

Gitanjali Rao, an 11-year-old seventh grader in Lone Tree, Colorado just won the 2017 Discovery Education 3M Young Scientist Challenge, taking home $25,000 for the water-quality testing device she invented, called Tethys.

Rao was inspired to create the device after watching Flint's water crisis unfold over the last few years. In 2014, after the city of Flint cut costs by switching water sources used for its tap water and failed to treat it properly, lead levels in the city's water skyrocketed. By 2015, researchers testing the water found that 40 percent of homes in the city had elevated lead levels in their water, and recommended the state declare Flint's water unsafe for drinking or cooking. In December of that year, the city declared a state of emergency. Researchers have found that the lead-poisoned water resulted in a "horrifyingly large" impact on fetal death rates as well as leading to a Legionnaires' disease outbreak that killed 12 people.

A close-up of the Tethys device

Rao's parents are engineers, and she watched them as they tried to test the lead in their own house, experiencing firsthand how complicated it could be. She spotted news of a cutting-edge technology for detecting hazardous substances on MIT's engineering department website (which she checks regularly just to see "if there's anything new," as ABC News reports) then set to work creating Tethys. The device works with carbon nanotube sensors to detect lead levels faster than other current techniques, sending the results to a smartphone app.

As one of 10 finalists for the Young Scientist Challenge, Rao spent the summer working with a 3M scientist to refine her device, then presented the prototype to a panel of judges from 3M and schools across the country.

The contamination crisis in Flint is still ongoing, and Rao's invention could have a significant impact. In March 2017, Flint officials cautioned that it could be as long as two more years until the city's tap water will be safe enough to drink without filtering. The state of Michigan now plans to replace water pipes leading to 18,000 households by 2020. Until then, residents using water filters could use a device like Tethys to make sure the water they're drinking is safe. Rao plans to put most of the $25,000 prize money back into her project with the hopes of making the device commercially available.

[h/t The Cut]

All images by Andy King, courtesy of the Discovery Education 3M Young Scientist Challenge.

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Hulton Archive/Getty Images
6 Radiant Facts About Irène Joliot-Curie
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Hulton Archive/Getty Images

Though her accomplishments are often overshadowed by those of her parents, the elder daughter of Marie and Pierre Curie was a brilliant researcher in her own right.


A black and white photo of Irene and Marie Curie in the laboratory in 1925.
Irène and Marie in the laboratory, 1925.
Wellcome Images, Wikimedia Commons // CC BY 4.0

Irène’s birth in Paris in 1897 launched what would become a world-changing scientific dynasty. A restless Marie rejoined her loving husband in the laboratory shortly after the baby’s arrival. Over the next 10 years, the Curies discovered radium and polonium, founded the science of radioactivity, welcomed a second daughter, Eve, and won a Nobel Prize in Physics. The Curies expected their daughters to excel in their education and their work. And excel they did; by 1925, Irène had a doctorate in chemistry and was working in her mother’s laboratory.


Like her mother, Irène fell in love in the lab—both with her work and with another scientist. Frédéric Joliot joined the Curie team as an assistant. He and Irène quickly bonded over shared interests in sports, the arts, and human rights. The two began collaborating on research and soon married, equitably combining their names and signing their work Irène and Frédéric Joliot-Curie.


Black and white photo of Irène and Fréderic Joliot-Curie working side by side in their laboratory.
Bibliothèque Nationale de France, Wikimedia Commons // Public Domain

Their passion for exploration drove them ever onward into exciting new territory. A decade of experimentation yielded advances in several disciplines. They learned how the thyroid gland absorbs radioiodine and how the body metabolizes radioactive phosphates. They found ways to coax radioactive isotopes from ordinarily non-radioactive materials—a discovery that would eventually enable both nuclear power and atomic weaponry, and one that earned them the Nobel Prize in Chemistry in 1935.


The humanist principles that initially drew Irène and Frédéric together only deepened as they grew older. Both were proud members of the Socialist Party and the Comité de Vigilance des Intellectuels Antifascistes (Vigilance Committee of Anti-Fascist Intellectuals). They took great pains to keep atomic research out of Nazi hands, sealing and hiding their research as Germany occupied their country, Irène also served as undersecretary of state for scientific research of the Popular Front government.


Irène eventually scaled back her time in the lab to raise her children Hélène and Pierre. But she never slowed down, nor did she stop fighting for equality and freedom for all. Especially active in women’s rights groups, she became a member of the Comité National de l'Union des Femmes Françaises and the World Peace Council.


Irène’s extraordinary life was a mirror of her mother’s. Tragically, her death was, too. Years of watching radiation poisoning and cancer taking their toll on Marie never dissuaded Irène from her work. In 1956, dying of leukemia, she entered the Curie Hospital, where she followed her mother’s luminous footsteps into the great beyond.


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