Based on modern epidemiological studies, the authors of a new study estimated that lead air pollution during the Pax Romana would have caused an average increase in blood lead levels during childhood of about 2.4 micrograms per deciliter.
Lead mining during Roman times exposed the population to high levels of exposure to this metal and, in the case of children, may have caused widespread cognitive declines of between 2.5 and 3 IQ points.
led by and published by relied on Arctic ice core records and atmospheric aerosol models to estimate the concentrations and possible health impact of lead in European air during the heyday of the Roman Empire, the so-called Pax Romana, it reported on Monday. the Efe agency.
Historical and archaeological records indicate that European populations in Roman times had high levels of exposure to leadamong other things due to atmospheric pollution associated with large-scale mining and smelting of silver and lead ores.
Exposure to lead is responsible for a range of effects on human health and even relatively low levels affect children’s cognitive development.
Arctic ice was key to discovery
The team examined three ice records to determine levels of lead contamination in the Arctic between 500 BC and 600 AD, a period from the rise of the Roman Republic to the fall of the Roman Empire, focusing on the roughly 200 years of its heyday. last.
Lead isotopes allowed the team to identify mining and smelting operations across Europe as the likely source of contamination during this period.
Advanced computer modeling of atmospheric movement has also produced maps of lead air pollution levels across Europe.
According to research, during the nearly 200-year heyday of the Roman Empire, more than 500 kilotons of lead were released into the atmosphere.
The analysis indicated that European lead emissions rose sharply around 15 BC after the rise of the Roman Empire, remained high until the decline of the Pax Romana, which began around 165 AD, and were not surpassed until the beginning of the second century. millennium AD
Blood lead levels increased
Based on modern epidemiological studies, the authors estimated that lead air pollution during the Pax Romana would have caused an average increase in blood lead levels during childhood of about 2.4 micrograms per deciliter.
According to the authors, this exposure to lead in childhood would have caused widespread cognitive declines between 2.5 and 3 IQ points (intelligence quotient) throughout the Roman Empire.
“Lead is known to have a wide range of effects on human health, but we decided to focus on cognitive impairment because it’s something we can put a number on,” explained study co-author Nathan Chellman.
A reduction in IQ from 2 to 3 points “doesn’t seem like a big deal, but if it were applied to the entire European population, It’s a big problem” added Chellman, in a statement released by the Desert Research Institute.
Risks of lead exposure
In adults, high levels of lead exposure are associated with infertility, anemia, memory loss, cardiovascular disease, cancer and reduced immune response, among other effects.
In children, even low levels of exposure have been linked to reduced IQ, problems concentrating, and lower academic success.
“This is the first study to take a pollution record from an ice core and invert it to obtain atmospheric pollution concentrations and then assess human impacts,” noted the study’s lead author, Joe McConnell, quoted in communicated.
Importance of lead
Lead was one of the first metais to be mined by human beings due to their abundance in nature, but also to the ease with which it could be extracted.
In the Roman Empire this toxic mineral was widely used to construct plumbing pipes and sewerscoins and containers of various shapes.
It was still used as a base for paints and cosmetic products, but also to military purposes, namely for the manufacture of projectiles that were launched through slingshots and catapults.
