Did lead poisoning contribute to the fall of the Roman Empire?

Question

The Roman Empire used a lot of lead. It was important component of their plumbing (the english word itself is derived from the latin word for lead). They even used it to sweeten wine and in food (reference):

Lead's sweet overtones ... were thought to add complementary flavors to wine and to food as well. The metal enhanced one-fifth of the 450 recipes in the Roman Apician Cookbook, a collection of first through fifth century recipes attributed to gastrophiles associated with Apicius, the famous Roman gourmet. From the Middle Ages on, people put lead acetate or "sugar of lead" into wine and other foods to make them sweeter.

The article quoted above continues:

...some historians believe that many among the Roman aristocracy suffered from lead poisoning.

So is there other evidence that lead poisoning made a significant contribution to roman decline? Can we verify or refute this speculative theory?

Answer 1

I don't think it contributed (significantly) to the fall of the Roman empire.

The abstract of my source for this answer says the following:

Lead was known to the ancients from at least the 4 th millennium BC, but its use increased markedly during Roman times, to the extent that it became a health hazard. Mines and foundry furnaces caused air pollution; lead was extensively used in plumbing; domestic utensils were made of lead and pewter, and lead salts were used in cosmetics, medicines and paints. As a microbicide, lead was also used to preserve food. A grape juice concentrate (sapa) commonly used as a sweetener was prepared by preference in lead containers. Although Roman writers commented on the toxicity of lead, classic chronic lead poisoning was first described only in the 7 th century AD. Skeletal lead content increased significantly in the Roman era, but peaked at a level only 41-47% of that of modern Europeans. The authors thus suggest that chronic lead poisoning did not contribute significantly to the fall of the Roman Empire in the West. (p.1)

Let me expand a little. First of all, the dangers of lead poisoning were known.

The ancient writers were aware of the dangers of lead compounds. Dioscorides (v.9.103) writes that ceruse, taken internally, could be fatal, and that certain sweet wines could adversely affect the abdomen and the nerves; Pliny the Elder (H.N. xxxiv.50.167; 54.175; xiv.22) notes the poisonous nature of lead fumes, the toxicity of certain lead compounds, and the diverse effects of wine containing sapa on different people; Celsus (De Medicina v.27.10-12) refers to the poisonous nature of white lead; Vitruvius (viii.6, 10, 11) writes that lead pipes cause disease (but as an architect continues to prescribe lead plumbing). Nicander, the Greek physician-poet of the 2 nd century BC, is generally credited with the first description of lead poisoning. His poem about a disease caused by ceruse (lead carbonate), translated by Major (1959:312), describes what could well be acute lead poisoning, with acute symptoms of abdominal discomfort, vomiting, a sore mouth with an acrid taste, painful muscles and progressive paralysis, involuntary eye movement, disturbance of balance, hallucination and finally death (if untreated). It is noteworthy, however, that the clinical picture of chronic lead poisoning as we know it was not recognisably described in the period under discussion. (p.157)

So, in a nutshell, they did know one should be careful with lead. However, lead played a major role in the Graeco-Roman era. The main sources of pollution include (pp.155-156):

• Lead pipes and lead-lined canals
• Lead-containing paints and lead compounds in medicines and cosmetics
• The pollution of food, wine and olive oil as a result of their preparation in pewter or lead containers and the addition of sugar of lead or sapa
• Workers in lead mines, foundries and lead production plants were most exposed to lead pollution. It has been estimated that approximately 80 000 workers could have been involved annually at lead mines or foundries, and a further 60 000 in the manufacturing industry.

However, none of this proves (nor disproves) actual lead poisoning and its potential role in the decline of the Roman Empire. For that, we should look at archeological findings:

The determination of bone lead levels relevant to this study has been performed by Grandjean (1978:304-6); there are extant Sudanese skeletons dating back as far as 3 300 BC, prehistoric Danish remains (Waldron & Wells 1979:102-15); skeletons from Britain, from the Roman occupation era (Aufderheide et al. 1981:285-91), remains from the North American colonial period (Drasch 1982:199-231), and skeletons from Peru (500-1 000 AD) and Europe (18 th century BC to 20 th century AD). The findings may be summarised as follows:

• If the Sudanese and Peruvian data are taken as providing “zero values” for lead pollution, then the levels of lead in bone from that time to the modern period may be described as having multiplied from twenty-fold (Drasch 1982:199) to a hundred-fold (Grandjean 1978:305).

• Despite wide intra-group variation, well-to-do communities demonstrate higher lead levels than the less well-off, and urban communities higher levels than rural populations.

• In occupied areas during the late Roman era, lead levels were at 41-47% of present-day European levels. After AD 500 the levels dropped to 13% of modern levels, but during the Middle Ages they increased again to approximately the same levels as those of ancient Rome.

• Lead levels in the Roman capital were not significantly higher than in European legionary cities such as the present-day Augsburg. (p.158)

In the final chapter, the authors mention several authors who have written on the topic (and also mention some of their own thoughts). A very strong argument against the lead-poisoning hypothesis, is the following:

If lead pollution was indeed a serious problem in ancient Rome, the question arises as to why the typical clinical picture of chronic lead poisoning was not described, while the toxicity of lead compounds was apparently realised. (p.160)

and

Archaeological evidence based on the determination of lead in skeletons confirms that the average lead burden of the population of ancient Rome was less than half that of modern Europeans. (p.160)

Their conclusion:

In conclusion, it could be argued that the increased lead production which began in the 2 nd millennium BC reached its zenith in ancient Rome. The accompanying lead pollution led to a drastic increase in the lead burden of the population, and in well-to-do communities in particular. Although clinical lead poisoning may well have occurred from time to time in certain areas and certain population groups, archaeological findings indicate that the average lead burden in the population was less than half that of a modern European living in the same area. The typical picture of chronic lead poisoning was not described until the 7 th century AD. It is thus unlikely that lead poisoning could have had enough impact to have played any significant role in the decline of the Roman Empire in the West or its eventual fall towards the end of the 5 th century AD.

Source (by Francois Retief and Louise P. Cilliers): http://www.ajol.info/index.php/actat/article/viewFile/52570/41176