Using the figure from the Wikipedia article on the Suez Canal, around 1.5 million people worked on the construction of the canal in total. At any one time, over 30,000 people would be working on the canal project. Building the canal took up to eleven years: 1859 is given as the starting year of works on the shore near what would later be Port Said and the canal was inaugurated in 1869. If we assume the figure of 120,000 to be true, that would be not quite 11,000 deaths a year or an average of about 30 deaths a day. With figure of around 30,000 workers at any given time, this corresponds to an annual mortality rate of 364 deaths per 1000 workers.
By comparison, when de Lesseps attempted the construction of the Panama Canal starting in 1881, severely underestimating the conditions of the tropical rainforest, tropical diseases such as malaria and yellow fever
killed thousands of workers; by 1884, the death rate was over 200 per month.
(Source: Wikipedia article on the Panama Canal, section French construction attempts, 1881–1894; further source therein)
A death rate of 200 per month roughly equates to 20 per three days or 7 per day. Thus, at the very least in a single month the Suez Canal’s monthly death rate should significantly exceed that of the Panama Canal. The Panama Canal’s death figures are easily retrieved by web searches (terms: ‘panama canal workers death’) which bring up various pages confirming upwards of 22,000 casualties during the French construction period (e.g. here). There is even a separate Wikipedia page on Health measures during the construction of the Panama Canal.
Repeating the search but replacing the word Panama by Suez gives far fewer indications of significant death tolls. In fact, hard figures – even estimates – are rather hard to come by. One of the few indications I was finally able to find is F. W. P. Cluver’s contribution to the South African Medical Journal which reads:
One of the earliest large-scale attempts to control malaria
and other mosquito-borne diseases, such as yellow fever,
preceded the construction of the Panama Canal. It will be
recalled that after the Suez Canal was built an attempt was
made to cut this Canal by the eminent French engineer, de
Lesseps. This attempt proved a ghastly failure. Workmen died
in their thousands and after expending vast sums of money the
scheme had to be abandoned owing to the ravages of what
we now know to be mosquito-borne diseases. (F. W. P. Cluver, South African Medical Journal, 1950, 24, 327–328.)
This strongly implies that the Suez Canal’s death toll is far lower than the Panama Canal’s; as otherwise the constrast of Suez Canal versus the ‘ghastly failure’ Panama Canal would not make sense.
With this amount of evidence for the Panama Canal, absence of corresponding evidence for the Suez Canal where it would be expected corresponds to evidence to the contrary.
One of the few sources that actually does state numbers – albeit selected, potentially hand-picked – is Arnold T. Wilson on page 31 of his book The Suez Canal (link to archive.org).
But the allegations, made even by responsible writers, of the heavy loss of life amongst the labourers of the Canal are in no way borne out by the published statistics of the Company’s chief medical officer which give the mortality per thousand
- in 1863 as 1.40
- " 1864 " 1.36 average working staff
- " 1866 " 2.49 • • • 18,605
- " 1867 " 1.85 • • • 25,770
- " 1868 " 1.52 • • • 34,258
Source: Arnold T. Wilson, The Suez Canal: Its Past, Present and Future Second edition; Oxford University Press (London, New York, Toronto); 1939.
Being generous to the claim and taking the maximum numbers plus a security margin, I am able to arrive at a maximum of around 120 fatalities per year (assuming a mortality rate of 3 per 1000 and 40,000 working staff); using the highest figures published tops the number of fatalities at 85 and using the figure of 1868 allows us to estimate 52 fatalities in that year.
I note that only five of eleven years are quoted in the work. Furthermore, Britannica.com notes a cholera epidemic in 1865, conveniently the single year that Wilson chooses to skip. It is also noted in a few places including Wikipedia that the initial years were the toughest because a fresh water canal had to be built as part of the project. Still, the numbers we have fall short of the required estimate by an order of magnitude so even through cherry picking it seems unlikely to reduce them that harshly.
Unfortunately, I was not able to track down the original documents Wilson cites.
Where does the figure of 120,000 come from?
Wikipedia actually mentions this number albeit much further up on the page in the section Canals dug by Necho, Darius I and Ptolemy:
According to the Histories of the Greek historian Herodotus, about 600 BCE, Necho II undertook to dig a west–east canal through the Wadi Tumilat between Bubastis and Heroopolis, and perhaps continued it to the Heroopolite Gulf and the Red Sea. Regardless, Necho is reported as having never completed his project.
Herodotus was told that 120,000 men perished in this undertaking, but this figure is doubtless exaggerated. According to Pliny the Elder, Necho's extension to the canal was about 57 English miles, equal to the total distance between Bubastis and the Great Bitter Lake, allowing for winding through valleys. The length that Herodotus tells, of over 1000 stadia (i.e., over 114 miles (183 km)), must be understood to include the entire distance between the Nile and the Red Sea at that time. (Emphasis mine)
After the bolded sentence, the following reference is given:
"The figure ‘120,000’ is doubtless exaggerated. Mehemet Ali lost only 10,000 in making the Mahmûdieh Canal (from the Nile to Alexandria)." remarked W. W. How and J. Wells, A Commentary on Herodotus.
Herodotus’ number is also referred to by the Encyclopædia Britannica from 1911; they do not comment on whether it is considered a reasonable estimate.