Michel Poulain was born in Châtelet, a coal mining town in the province of Hainaut. Hainaut has the lowest life expectancy in Belgium: 79.3 years. The highest province, Flemish Brabant, hits 83.4. That’s a four-year gap. For men, it’s five.
Poulain studied astrophysics at the University of Liège, then switched to demography at UCLouvain. In 2000, working with a Sardinian physician named Gianni Pes, he validated clusters of centenarians in Sardinia’s Nuoro province. To mark the area on their map, they drew concentric circles in blue ink.
Blue Zones. That’s it. That’s where the name comes from. Blue pen on paper.
Dan Buettner took the concept to National Geographic and the world. Five places where people live remarkably long: Sardinia, Okinawa, Ikaria, the Nicoya Peninsula, Loma Linda. The methodology Poulain built — cross-referencing civil and ecclesiastical birth records, calculating the probability that newborns become centenarians — became the gold standard for longevity research.
The man who invented the tool to find where people live longest was born in the place where they live shortest.
Now a €3.14 million EU-funded study called IMR Blue Zone is putting smartwatches on participants in the Meuse-Rhine region. The study towns include Pepinster, Seraing, and Chaudfontaine — all in the province of Liège, just down the road from Poulain’s astrophysics classroom.
The project isn’t looking for exceptional longevity. It’s trying to understand why neighboring towns across national borders — Belgian, Dutch, German — have such different life expectancies. The question isn’t “what makes people live long?” It’s “what makes people here die sooner?”
The concept has been inverted. Blue Zones originally mapped something rare and beautiful — communities where the right combination of diet, movement, connection, and purpose produced century-long lives. Now the same brand maps the opposite.
Poulain isn’t involved in the study.
The corridor responsible is called the sillon industriel — a 200-kilometer strip following the Sambre and Meuse river valleys, from Mons through Charleroi and Namur to Liège and Verviers. For two hundred years, this was the engine of Belgium.
The first Newcomen steam engine on the European continent was installed in a Liège coal mine in the 1720s. By the 1830s, Belgium was the second most industrialized nation on Earth, driven almost entirely by this corridor. In 1908, 145,000 people worked in coal mining alone. John Cockerill’s steelworks at Seraing was called the largest factory in the world.
In 1930, an atmospheric inversion trapped emissions from thirty industrial facilities between Liège and Huy. Sixty-three people died in five days. Thousands more suffered acute respiratory distress. Cattle collapsed in fields. This was the first scientific proof that air pollution could cause mass death — twenty-two years before London’s Great Smog.
The factories kept running.
In 1956, fire swept through the Bois du Cazier coal mine at Marcinelle. Two hundred sixty-two miners died, 136 of them Italian immigrants who’d been recruited with no training and housed in former prisoner-of-war camps. European mine safety regulations were rewritten from scratch.
By the 1960s, the collapse had begun. Coal production fell from 29 million tons in 1957 to nearly nothing by the 1990s. Fifty thousand jobs vanished between 1960 and 1973. The Vesdre valley around Verviers, which had been “Wool Capital of the World,” lost its textile industry even earlier than the coal belt lost its mines.
Then the steel left too. In 2011, ArcelorMittal ended all liquid steel production in Liège. Workers physically barricaded executives inside the plant in protest. Unemployment in Seraing reached 27%.
What the sillon left behind is not just poverty. It’s a health scar written into the population.
Smoking: 18% in Wallonia vs. 13% in Flanders. Obesity: 22% vs. 16%. Both strongly correlated with education levels, which are strongly correlated with economic opportunity, which follows the geography of deindustrialization like a shadow.
The soil is still contaminated. Cadmium, lead, and zinc from historical smelters persist in the ground. Researchers have documented elevated heavy metals in agricultural soils and renal dysfunction in populations consuming contaminated vegetables and well water. The coal dust is in the lungs. The chemicals are in the kidneys. The factories closed decades ago but the dying didn’t stop.
And in July 2021, the rivers came for what was left. Storm Bernd dropped 271 millimeters of rain in 48 hours on the Ardennes. Pepinster sits at the confluence of the Vesdre and Hoëgne — two rivers surging simultaneously into a bottleneck. Twenty-three of Belgium’s thirty-one flood deaths happened in Pepinster alone. Fifty buildings demolished. Five hundred residents left and haven’t come back.
A study of flood survivors found that 54% reported worse psychosocial wellbeing two to three years later. The strongest risk factors: lower socioeconomic status and more direct flood experience. The people most damaged by the flood were already the most vulnerable. The disaster didn’t create inequality. It amplified the inequality that was already there.
Pepinster is now one of the IMR Blue Zone study towns.
In 2024, Saul Newman won the first-ever Ig Nobel Prize in Demography for arguing that supercentenarian data mostly reflects pension fraud and bad record-keeping. In the United States, the introduction of birth certificates correlated with a 69-82% drop in supercentenarian claims. In Japan, 82% of supposed centenarians turned out to be already dead.
Poulain published a defense in January 2025. Sardinia’s civil registration has been dual-tracked since 1866 — civil and ecclesiastical records, filled out by trained officers, bound chronologically. “For none of the Sardinian supercentenarians identified so far, a discrepancy between civil and ecclesiastical data has been found, with only one exception.”
So the concept is under siege from two directions at once. Newman says the longevity data is largely fraud. The IMR study uses the brand to map the opposite of longevity. The blue ink on Poulain’s map has bled into places he never intended it to reach.
There’s a question in health geography called “composition versus context.” Does a place shape the health of its people, or does it simply contain people who happen to be healthy or sick?
A 2016 JAMA study by Raj Chetty found that men in the bottom 5% of income who lived in New York could expect to live five years longer than men with comparable incomes in Gary, Indiana. What correlated with longer life for the poor wasn’t medical care access. It was college graduates nearby, immigrants, government spending, less smoking.
In Belgium, the answer seems clear: the sillon created the conditions. Two centuries of heavy industry selected for a population, shaped its behaviors, contaminated its soil, filled its lungs, then left. The factories are gone. The patterns remain. Deindustrialization created poverty, poverty created behaviors, behaviors created mortality, mortality became geography.
Place shaped people who now shape the place. The circle draws itself in blue.