A number of factors can lead to the death of an entire civilization. For example, the fall of the Roman Empire in 476 AD. The slow decline of the empire is usually attributed to barbarian invasions and failed military campaigns, economic problems, government corruption, over-reliance upon slave labor, and other factors. It has also been suggested that lead poisoning may have contributed to the empire's decline. This debate was revisited by the American Chemical Society in Reactions 2.There are many properties that make lead attractive for practical purposes. It is inexpensive, readily available, resistant to corrosion when exposed to water and air, and highly malleable which makes it easy to make a variety of products. However, lead can be toxic to the body if it gets into the bloodstream. This is why we use less of it today than 100 years ago. Anemia, nerve disorders and infertility are all common signs of lead poisoning. Malaria, rickets and gout may all be caused by lead exposure.Scientists have known since 1943 that lead can cause behavioral problems in children and lower intelligence. It can replace calcium easily. Calcium is what neurons in the brain communicate. If lead replaces calcium, it can either cause too little or too much communication. This can lead to mood swings or difficulties processing information.Reactions' video shows that the Romans loved their lead. It was used in pipes and coffins, as well as in pots and utensils. In an era when honey and cane sugar were scarce, they also used lead as a sweetener. The grapes were plentiful and they used their lead pots to boil the juice. The juice would then be contaminated with lead ions, which would combine with the acetate derived from the grapes. The syrup was extremely sweet and could be used to make wines as well as a variety of other foods. One hundred recipes from the Apicius cookbook, which dates back to that time, called for these syrups. Romans loved wine. Aristocrats consumed between 1 and 5 liters per day. Some syrups were recreated by researchers who found lead levels that were 60 times greater than what the EPA allows for public drinking water.AdvertisementThe current debate over lead poisoning's possible role in the fall of the Roman Empire stems from a 1983 paper published in the New England Journal of Medicine. It was written by Jerome Nriagu who was studying the diets of Roman Emperors between 30 BC & 220 AD. Nriagu found that 19 of 30 Roman emperors preferred "lead-tainted food and wine," concluding that many were likely to have suffered from gout or lead poisoning.Claudius is said to have "disturbed speech," weak limbs, ungainly gait and tremors. He also often slobbers. Legend says that Caligula once wanted to appoint Incitatus as his consul. However, historians believe that this was political gossip or that Caligula meant it as a joke. Nero was said be to have mutilated people while wearing animal skins in the arena.Was lead poisoning responsible for all these symptoms and the eventual fall of the empire? Clair Patterson, geochemist, supported Nriagu's hypothesis and convinced governments to ban gasoline containing lead in 1975. It was hotly debated by others, including John Scarborough, a classicist who accused Nriagu's of poor research. In 2016, Nriagu told the Washington Post that Scarborough knew nothing about lead poisoning.In the decades that followed, many scientific papers have examined various aspects of lead poisoning. In 2014, French researchers looked at how lead pipes in Roman aqueducts could have polluted the water of ancient Romans. They measured the concentrations of lead in sediment from Trajanic Harbor and the Tiber River, and then compared them to the levels found in ancient Roman pipes.Although they estimated that the pipes' water could have contained as much as 100 times more lead than the spring water in the area, the team concluded that these levels weren't likely have caused any serious health problems. According to the authors, the theory of lead poisoning being responsible for the fall the Roman Empire has been disproven.AdvertisementThere could also be other factors that contributed to the bizarre behavior and illnesses of the ancient Roman rulers. These could include strokes, brain traumas or tumors. There is evidence that lead poisoning was an issue in the Roman Empire, even though it did not directly cause its collapse. A 2010 study on dental enamel from over 200 burials in 33 locations in Britain, Ireland and Rome (circa 1st to 4th centuries AD) revealed a significant increase in lead levels in British samples and a wide range in Roman enamel samples.Archaeologists analyzed skeletons dating back to the Roman period in London for evidence of lead exposure. As a control, the team also sampled 70 bones from Iron Age. The Iron Age skeletons had a concentration of 0.3 to 2.9% lead per gram. By contrast, the Roman Empire skeletons had between 8 and 123 micrograms. These levels are high enough to have widespread health effects such as hypertension, fertility problems (and subsequent population decline), kidney disease and neural damage, and other issues.Janet Montgomery, an archaeologist at the University of Durham, says that bone absorbs lead from the soil. It can be difficult to determine if there is post-burial contamination. She told Chemistry World that it is difficult to determine if the lead in bone has been accumulated from low levels of exposure over a long period of time or if it was a result from a single high-level exposure in the past or something else.Forbes writer Kristina Killgrove pointed out that there weren't any lead grave goods or coffins at these sites, which could have contributed to the contamination. However, she noted that it is not clear if the skeletons of those who lived in Rome during this period (as opposed London) also showed high levels of lead. This requires further research. Killgrove stated that while the issue of lead poisoning in the Roman Empire remains unsolved, this research contributes to the growing body scientific data from multiple sources that shows human-caused lead pollution was a serious problem two millennia ago.Listing image by iSidhe/iStock/Getty Images
