A lot has been said about what may have caused the decline of the Roman Empire. Was it its conversion to Christianity? An environmental catastrophe in the wake of a volcanic eruption? Or was the widespread exposure to lead the culprit?
Many historical texts describe symptoms that suggest that the Ancient Romans indeed suffered from lead poisoning, but its role in the ultimate decline of the Roman Empire is still refuted by many scholars. It’s unlikely we’ll ever learn what really caused its decline, but what we can do is learn more about how lead poisoning affected Roman citizens by studying archaeological remains.
Lead is a cumulative poison: it doesn’t kill you immediately, but exposure over longer time can be lethal as it accumulates within the human body. Lead cannot be avoided completely, because it can be found everywhere in the natural environment: traces of lead can even be found in the tooth enamel of pre-Roman populations.
What makes the Romans special, is that they really, really liked to use lead for pretty much everything. This means that the average Roman citizen was repeatedly exposed to lead via water sources, medicines, utensils, cooking pots, food preservatives, sweeteners, household items, coins, toys, and possibly through .
Children were particularly susceptible to lead poisoning, as their growing bodies absorb higher quantities of ingested lead. Many Roman children did not make it to adulthood. Up to 50% of children died before the age of 10, and 20–40% of those did not even survive their first year. It is therefore not surprising that many infant remains can be found in Roman cemeteries throughout the Roman Empire.
This study investigates the degree of lead toxicity in cemeteries from four different regions of the empire, which are chosen such that they are 1) representative of the geographical diversity of the empire, 2) far away from major lead mining and production centres (to mitigate effects on environmental lead pollution), and 3) included individuals from various socioeconomic strata.
The degree of lead toxicity is linked to the impact on childhood health and mortality using a combination of two methods:
Paleopathological analysis involves of human remains, which can provide evidence that an individual suffered from metabolic diseases that are often associated with lead poisoning, like rickets, scurvy, and anemia.
Lead trace element analysis on tooth enamel shows how much lead has accumulated within individuals at the time of their death.
The results show that individuals who managed to survive into adulthood had lower lead concentrations than those who died during childhood. The latter had more than twice the amount, which suggests that high concentrations of lead are accompanied by lower life expectancies. It is clear that a negative correlation exists between lead concentration and age at death.
- Lead poisoning is a probable cause of the high infant mortality rates in the Roman Empire