Cognitive archaeology: estimating the effects of blood-lead concentrations on the neuropsychological function of an officer of the 1845 Franklin expedition

• Published in: Journal of Archaeological Science: Reports
• Main Authors: Millar, Keith, Bowman, Adrian W.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2020
• Subjects: Arctic
• Online Access: http://eprints.gla.ac.uk/218813/; http://eprints.gla.ac.uk/218813/7/218813.pdf

Lead poisoning has been implicated in the loss in the Arctic of all 129 officers and men of the British Royal Naval “Franklin expedition” of 1845. In a unique study, D’Ortenzio et al. (2018) estimated blood-lead concentrations of an officer of the expedition over the three months prior to his death which is thought to have occurred before the desertion of the expedition’s ships. The present study applies regression coefficients which quantify the relationship between blood lead and neuropsychological function to the data of D’Ortenzio et al. to estimate whether the officer’s lead exposure would have impaired his cognitive performance in the critical period prior to the desertion. It is shown that the blood-lead concentrations would have been associated with only small deficits in higher-order cognitive processes including attention, visual scanning, memory and decision-making which would not have been of functional significance. Greater deficits were associated with psychomotor functions involving eye-hand co-ordination and fine motor control which, although not defined formally as “impairment”, might have affected accuracy when using firearms or operating instruments relevant to the scientific objectives of the expedition. The study also reviews evidence that the levels of lead in the Franklin crew, while high relative to today, were typical of those of the lead-exposed Victorian population from which they were recruited. The results contribute to evidence that lead exposure did not play a significant role in the loss of the Franklin expedition.