Surfers, divers, and others who sometimes find themselves in cold water, a condition known as "Surfer's Ear," in which a small bony prominence forms in the temporal bone that blocks a part of the ear canal. Archaeologists have recently found the same bony growths in the skulls of people who lived 2,400 years ago in pre-Columbian Panama. They suspect that the skulls are the remains of a seasoned pearl diver who spent his life collecting precious objects on the ocean floor.
Under the surface
The skulls were part of a large collection that was studied by archaeologists Nicole Smith-Guzman and Richard Cooke of the Smithsonian Tropical Research Institute. They found the telltale humps on the temporal bones of eight skulls with intact auditory canals-seven men and one woman. In the skulls, which still had intact ear canals on both sides, 12.2 percent of men and 3.3 percent of women had a surfer ear on at least one side. Most had mild or moderate cases, but one man had enough growth to block more than two thirds of his ear canal, possibly causing an audible hearing loss.
The relatively low frequency of growth points to a select group of mostly men who for some reason regularly ended up with cold water in the ear canals.
Panama is a tropical patch, but the water in the Gulf of Panama on the central Pacific coast of the country can get quite chilly. From January to April, the trade winds from the north blow most of the warm surface water out of the sea, and colder water gushes from the depths to replace it. With an average surface temperature of 19 ° C, the Golf is cold enough to risk a surfing ear.
Most people who live on the shores, especially males, probably spent a lot of time on the water because they fished out of boats was an important part of the local economy. If the cool salty blast and the fresh sea breeze were enough to cause a surfer's ear, you would expect more than one in ten pre-Columbian villages on the Gulf to develop the problem. The relative rarity of the disease suggests that a small number of people on the coast of Panama made something diving and dived for oysters.
An Occupational Risk
The divers had played a key role in Panama's pre-Columbian economy. Shell jewelry, silver mother-of-pearl and orange and violet thorn oysters traveled along the trade routes to Mexico and the Andes. Archaeologists have shell jewelry in tombs from the year 400 BC. Found. The organisms that have made the largest and most valuable of these shells have anchored themselves in clear water on the rocky sea floor, so deep that only experienced freedivers could reach them. The Spanish conqueror Vasco Nuñez de Balboa described experienced divers who floated 7.9 meters (24 feet) down to oysters from the rocks.
These divers began their training as infants after Balboa. Everyone in Smith-Guzman's and Cookes Surfer's Ear Surveys lived at least 35 years old, so for decades they plunged into the cold waters of the Gulf of Panama to bring valuables. This long-term exposure could explain the cases of surfer ear, which takes several years to develop.
Doctors think Surferohr happens because the thin skin of the ear canal does not protect the bone from cold water, causing inflammation to the membrane on the outside of the bone, called periosteum. Over time, this inflammation turns so that the bone lays additional layers, much like the spores of the bone form. This increases the risk of infection as it is more difficult to remove water and debris from the ear. A serious case – one that blocks more than two-thirds of the ear canal – can lead to hearing loss.
Elsewhere in the Panama coast, the water stays warmer all year round. There were no traces of surfer ears in the remnants of these shores, though people almost certainly dived for oysters and clams there. But Smith-Guzman and Cooke were only able to inspect five skulls from locations on the Caribbean coast and the Gulf of Chiriqui, so they do not have enough information yet to be sure that pearl divers in those places definitely had no surfing ears. They hope to be able to change this with future studies.
"We would like to do a follow-up study looking at skulls from a much larger area and also doing a survey among doctors in Panama to find out if they are surfers or divers. I've always been using surfers these days & # 39; 's ear shown, "said Smith-Guzman in a statement.
American Journal of Physical Anthropology 2018. DOI: 10.1002 / ajpa.23757 (via DOIs).