Toxicity in the atmosphere of the ancient empire would have been high enough to kill brain cells and lower the entire civilisation’s IQ.
According to a new study of Arctic ice core samples, a team at Canada’s Simon Frasier University now believe silver mining and smelting could have directly contributed to the fall of the Roman Empire.
Although this may sound far fetched, historians have long mused over whether gradual and widespread lead poisoning helped catalyse or contributed to societal decline. The Romans used lead for a variety of processes, including sweetening wine, pipework, utensils and cosmetics. Meanwhile, lead-silver ore was relied on to produce coins, with around 10,000 ounces of lead produced for every ounce of silver, with up to 4,600 tonnes of lead produce annually at the height of the empire.
A 180 year period of prolonged peace known as the Pax Romana which ended in 180 A.D., the regime was also at its richest, with more money being made and infrastructure built than during any previous point. While a number of factors triggered instability, including the death of Marcus Aurelius, the toxic metal would have entered the blood streams and respiratory systems of the population. The result being ‘widespread cognitive decline’.
‘This study and other evidence indicate that people who minimized the contribution of lead poisoning to the decline of the Roman empire need to revisit the evidence on low-level lead poisoning,’ said Bruce Lanphear, Health Sciences Professor at Simon Fraser University.
Publishing in the journal Proceedings of the National Academy of Sciences, the researchers suggest this could have even caused a drop of between 2.5 and 3 IQ points. Given the prevalence of lead pollution sources, this would have been the case across all urban and semi-urban parts of the empire.
‘I’m quite convinced lead was one of the factors that contributed to the decline of the Roman Empire, but it was only one factor,’ study co-author Joe McConnell, of the nonprofit Desert Research Institute in Nevada, explained to NBC News.
‘I leave it to epidemiologists, ancient historians and archaeologists to determine if the levels of background atmospheric lead pollution and health impacts we have identified … were sufficient to change history,’ he continued in a separate interview with The Guardian.
In the US, prior to bans on lead paint and leaded gasoline, studies of children in the 1970s revealed 15 micrograms of the toxic metal per decilitre of blood. It is believed this could have caused a 9-point decline in IQ. Similar restrictions were introduced in the UK following similar observations, wit the last tetraethyllead gasoline removed from British forecourts in 2000.
Nevertheless, the threat posed by lead poisoning persists. A 2021 Imperial College London study led by Dominik Weiss suggests there was still around 50 times more lead in the capital’s air than would natural occur at the beginning of this decade. Separate research last year by Dr Lucia Coulter, Lee Crawfurd, and Tammy Tan, published through UKDayOne, pointed to a ‘hidden epidemic’ of childhood lead poisoning caused by old pipework and paint, dating to before a 1976 ban on lead in housing.
99.9% of cases are not identified properly due to a ‘passive surveillance system’ which is ill equipped to identify historic dangers. Nevertheless, it’s thought that some of the most vulnerable households are the most effected, with overall lead poisoning costing the British economy billions – up to 4.4% of GDP – each year.
Earlier this month environmental scientists and animal rights activists renewed calls for a mandatory ban on lead ammunition being used to hunt red grouse and other game. Shots have been found to fragment on impact, with tiny particles polluting the countryside, and lead being absorbed into the flesh of dead birds.
This then enters the food chain in the form of contaminated meat. A voluntary ‘transition’ away from the toxic rounds began in 2020, but critics argue this has made little difference on the ground.
Game-shooting organisations have hit back, claiming an ‘unwavering commitment’ to the ammunition dump. The Moorland Association even went so far as to tell researchers working on the Cambridge University-led SHOT-SWITCH project that: ‘grouse moor owners have been at the forefront of the transition away from lead shotgun ammunition’.
‘Based upon this strong statement, it might be expected that quantitative evidence of change in practice on moorland shoots had already been obtained and that it showed that the voluntary transition from lead to non-lead ammunition was progressing as rapidly or more rapidly for red grouse shooting than it has been for pheasants,’ the response from SHOT-SWITCH read.
‘We are not aware of any such evidence. The results reported in this paper indicate that almost all red grouse continue to be shot using lead ammunition, even as the end of the transition period approaches,’ the team added.
Image: Mathew Schwartz via Unsplash
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