The Industrial Revolution was undoubtedly a major turning point in history. Starting in the late 1700s, human impact on the environment reached new heights never before possible. But pollution was not invented in the 18th century. Humans have been polluting the planet for much longer, to our own detriment, as new research links Pax Romana-era lead air pollution to cognitive decline. According to the study, people who lived during the Golden Age of the Roman Empire had an average IQ drop of 2.5 to 3 points due to lead in the atmosphere. the study Published in a magazine on January 6th Proceedings of the National Academy of Sciences.
New research adds: long-standing debate On the role that lead pollution and poisoning may have played in the fall of the Roman Empire. Some historians believe that Roman elites and emperors displayed in odd numbers, a lot of violent behavior Like Caligula and Nero, they actually suffered from lead poisoning, and the erratic behavior it caused severely undermined social stability. This study does not prove in any way whether or how the fall of Rome is related to the fall of Rome. However, evidence suggests that the effects of pollution on environmental health and people have roots dating back thousands of years.
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Scientists used Arctic ice cores, atmospheric modeling, epidemiological data, and previously published health and cognition research to show that fluctuating lead air pollution levels over centuries have contributed to people’s We are estimating how this may be reflected in blood lead levels and what effects those blood lead levels may have. It influenced the cognitive abilities of the inhabitants of the Roman Empire.
This study is not the first to find a significant peak in lead contamination and human lead exposure during Roman times. previous work have Established penetration rate of ancient lead pollution Through analysis of ice and peat cores, skeletal remains, and ancient infrastructure. However, this study is unique in that it quantified the effect of Roman-era contamination on blood lead levels and IQ decline. The authors found that for children who lived during the 200-year Pax Romana (c. 27 BC to ca. 180 AD), the average blood lead concentration was approximately 3.4 micrograms per deciliter (neolithic background levels) due to air pollution alone. It is estimated that it would have been 2.4 micrograms/dl higher. And these levels would correspond to a 2.5 to 3 point decline in IQ levels for the population as a whole.
IQ is a flawed metric, but best scientific shorthand It can be used to track the effects of things like lead on a population level. This metal is a well-established neurotoxin and is known to be particularly harmful to infants and children. Even low and moderate levels of lead exposure can cause lifelong health effects, including developmental delays, learning disabilities, behavioral changes, immunosuppression, heart disease, organ damage, and pregnancy complications. There is. According to , no level of lead exposure is considered safe. world health organization and Centers for Disease Control and Prevention. However, once lead enters the environment, it becomes impossible to avoid it.
The Roman Empire had many potential sources of lead exposure, from cookware and utensils to water pipes and wine. All of these likely contributed to the lead burden that people carried at the time. However, nothing was as widespread as air pollution, and even isolated rural populations could be exposed to toxins. The mining and smelting of metal ores, particularly galena, used as the raw material for the silver in Roman coins, produced lead emissions that had widespread effects throughout the Roman Empire.
“As far as I know, this is the first large-scale pollution event due to industrial activity,” he said. Joe McConnelllead author of the study and a research professor and hydrologist at the Desert Research Institute in Nevada. “Our aim here was to try to understand the potential health effects arising from: [that]” he added.
To do so, he applied his expertise in ice core analysis to evaluate samples from three different Arctic sites. Ice cores act as frozen records of atmospheric conditions throughout history, as particles circulating in the air eventually fall onto glaciers and ice sheets, where they are preserved in a literal timeline. Using these measurements of lead deposited in the Arctic throughout Roman times, McConnell and his colleagues applied an atmospheric model (the same kind used by climate scientists) to figure out how much lead was deposited in the skies over the Roman Empire. We used reverse engineering to estimate whether lead was circulating in the air. , thousands of kilometers from Greenland and Russia, where the samples were collected.
They ran two different model scenarios. One assumed that most of the lead contamination originated from known mining areas in present-day southern Spain, and the other assumed more dispersed sources of lead emissions from throughout the empire. Both scenarios resulted in similar estimates of atmospheric lead.
From there, the interdisciplinary research team turned to: modern environmental health analysis Establish a relationship between lead concentrations in the air and in people’s blood. Finally, they estimated how those levels affected cognitive performance. Using data about IQ loss from public health research.
“Our findings show that lead pollution not only has a clear impact on the air, but also on blood lead levels and cognitive impairment,” McConnell said. The levels of lead pollution in the air recorded in this study are lower than the peak of global lead pollution reached in the 20th century, when the use of leaded gasoline became widespread. But it’s still a noticeable and measurable effect, he says.
“Our data suggest that 180 years of lead pollution at the height of the Roman Empire had about a third as much impact on cognitive decline as during the height of exposure in the 20th century,” McConnell said. He explains. “The idea that 2,000 years ago, humans were polluting the European continent at a level one-third of modern industry is pretty amazing. Much of the environmental research suggests that the pre-industrial world was primitive. It was not the case.”
McConnell added that the study’s calculated lead exposure from air pollution represents the lower end of the level that people would realistically encounter. Air pollution would have been even worse in locations near mines and smelters. And many people living in the Roman Empire may have suffered further harm from high blood lead levels through water, food, and household products.
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“This is an interesting study. I agree with what they are trying to do,” he says. Sean Scotta chemist at the Pacific Northwest National Laboratory, has previously studied lead levels in Roman times through human remains. But Scott points out that by combining estimates and models, the researchers compounded the inherent unreliability of their method. “We’re confident that these measurements are very good, but when you make the leap from ice cores to human blood to intelligence, there are uncertainties,” he says. Indeed, “that’s the best they can do,” he added.
McConnell acknowledges this limitation. “It would be great to further quantify the relationship between background air pollution, blood lead levels in children, and health outcomes,” he says. Ideally, he points out, there would also be a way to quantify other health effects of lead and industrial pollutants.
Still, Scott says the new study serves as a sketch of “unprecedented environmental change” during an endlessly fascinating period in human history. It may be impossible to know exactly what caused the fall of the Roman Empire (both Scott and McConnell say it was likely not a single cause). But perhaps studying the pollution of this era might make people think about the similarities between history and modern times. “When you study the Roman population and its historical environmental science, and then look at modern times, you see the world differently,” Scott says. Perhaps the Romans did not fully understand the consequences of refining silver. “You wonder what we’re doing now that we don’t understand.”
