When was Mesothelioma Discovered

Anthophyllite asbestos from an electron Microscope

Mesothelioma is a rare form of cancer that forms on the "tissues that cover the lungs and abdomen." Mesothelioma is typically tied to the exposure of people to asbestos in either their environment or workplace. If asbestos exposure leads to mesothelioma it is extraordinarily serious, because it is an incurable and typically fatal type of cancer. The history of mesothelioma is complicated. Medicine struggled to establish its existence and understand what caused it.

Asbestos has been widely used by humans because it was extraordinary fire resistance and could be woven in fabrics. Unforunately, this has put humans into close contact with asbestos for over two millennia. Asbestos is comprised of fibrous silicates that are resistant "to thermal and chemical breakdown, tensile strength, and fibrous habit" that makes it possible to be "woven into textiles." It is not clear when humans first began using asbestos, but it has been used for at 2000 years.

While it took a long time for mesothelioma to be connected to asbestos exposure, it was well known that people could develop asbestosis. Asbestosis was caused by the scaring of the lungs by asbestos fibers. Asbestosis was caused by long-term exposure and while incurable it can in many cases be treated. Unlike mesothelioma, it was not necessarily fatal. Still in severe cases, patients may need lung transplants. Mesothelioma, on the other hand, is almost always fatal.

First Identification of Ailments caused by Asbestos

Asbestos has been used by humans since at least 2500 B.C.E. Because it was fireproof, asbestos was viewed as if it had almost magical aspects. Since asbestos deposits can be found around the world and are quite common, asbestos has utilized by societies throughout the world for thousands of years. The first known use was by Fins who included in their pottery to make it heat resistant. Its uses have varied widely. Egyptians wrapped embalmed Pharaohs in asbestos laced textiles to aid preservation. European blacksmiths also included asbestos in medieval armor. Large scale manufacture of asbestos textiles began in earnest after the discovery of large asbestos deposits in 1720 in the Ural mountains.

Despite its perceived magical properties, people noticed early on that exposure to asbestos could be dangerous. Roman historian and doctor Pliny the Elder (23AD to 79 AD) warned that slaves who worked in asbestos mines suffered disproportionally from serious lung ailments. He argued that it was risky to buy slave that worked in these mine because they died young. Plinny's observation was remarkably prescient, but medicine was not be able to diagnosis what was causing this malady for almost 2000 years. Mesothelioma resisted being diagnosed because the tumors associated with it were easily confused with tuberculous. It was impossible for physicians to diagnosis accurately the condition without microscopes. The symptoms of asbestosis would have been readily apparent because it caused people severe difficulties in breathing. Alternatively, mesothelioma was fatal and it could be mistaken for other diseases such as tuberculous or other cancers.

Mesothelioma Tumors

In 1767, Joseph Lieutaud, a renowned French pathologist and King Louis XVI's personal physician, published 2 cases of "pleural tumors" in the Précis de médecine pratique. Leiutaud wrote that the pleural tumors consisted of finding "fleshy masses" adhering to "the pleura and ribs." The tumors described by Lieutaud resembled tumors now known to cause mesothelioma. A German pathologist, von Rokitansky, in 1854 identified tumors that he described as "tumors of the peritoneum" and called "colloid cancer." While he correctly described the tumors, he misidentified them. In 1870, another German doctor, E. Wagner, published a paper that accurately distinguished mesothelioma tumors from tuberculous. Using a microscope, he discovered that the patients that had been diagnosed with tuberculous actually had malignant tumors in the pleura.

Slowly, physicians were beginning to successful identify the tumors that caused mesothelioma. Because these types of tumors were exceeding rare, it was challenging for physicians to identify them. Finally, in 1920, Ernest S. Du Bray and F. B. Rosson coined the term "primary mesothelioma of the pleura" in an American medical Journal and traced the history of the pleura tumors up until that point. Despite, Du Bray and Rosson's article, "doubting Thomases" still questioned whether pleura tumors were existed up until the late 1950s. Significantly, it took another 40 years for mesothelioma to be tied to the exposure to asbestos.

Making the Connection between Pleura Tumors and Asbestos

Finally in 1959, three South African physicians, J.C. Wagner, Kit Sleggs, and Paul Marchand published a medical paper linking the deadly form of cancer mesothelioma to asbestos. In 1956, Dr. Wagner faced was confronted with a series of patients that appeared to be suffering from tuberculous and emphysema in and around Kimberely, South Africa. Once these patients were identified it was decided that these patients had the best chance to survive if they were sent to a tuberculous hospital managed by Dr. Kit Sleggs in Kimberly. These patients were brought in from an enormous area surrounding Kimberely (currently famous the enormous open pit diamond mine next to the town). The doctors quickly learned that patients who lived east of Kimberely recovered from their illness, but patients who west of Kimberly did not respond and died. The physicians realized that the patients west of Kimberely were suffering from a different and far more dangerous disease than tuberculous or emphysema. After patients died, the autopsies showed that all of the patients from west of Kimberly suffered from extremely rare mesothelioma tumors. The doctors realized it was unlikely that these tumors were simply random.

The Big Hole next to Kimberely, South Africa

A pathologist who worked with Wagner in Kimberly, informed Wagner and Kleggs that he had seen similar mesothelioma tumors in Johannesburg, South Africa. Kleggs and Wagner contacted Dr. Paul Marchand, the physician who had treated many of the Johannesburg patients. The three physicians immediately suspected that blue asbestos might of the tumors. After taking another look at the samples of lung from deceased patients, they found fragments of asbestos mineral. Initially, the physicians struggled to link asbestos and mesothelioma for two reasons: First, many of the patients (both black and white) denied working in asbestos mines. Second, mesothelioma tumors were typically fatal within a year or two within diagnosis, but these patients were developing tumors 10-20 years after their first exposure to asbestos. The physicians needed to establish that the tumors were not a result of some other source. Eventually, the doctors realized that their patients had lied to them because their was social stigma attached to working with asbestos. The patients had worked in and around asbestos, but were loath to admit. Eventually, patients began to reveal that they had worked in asbestos mines or mills. In some cases, these patients described living in "a blue haze" in their communities that were located next to mines and mills. The mills and mines west of Kimberly worked with blue asbestos.

In order to determine if asbestos was the cause, the physicians had an unlikely resource. The South African Pneumoconiosis Bureau had keep records and samples of the thoracic organs of most of the miners who had died. The South African government had already determined that working with asbestos was dangerous, but they did not know exactly why. On the other hand, mining companies were not interested in delving too deeply into why their miners died. The physicians were allowed to review these samples and learned that miners exposed to amosite (blue) and occasionally chrysolite asbestos developed fatal pleura tumors. After further study, it became clear that all types of asbestos could cause cancer, but some types of asbestos were much more dangerous. It was also confirmed that cigarette smokers who were exposed to asbestos faced even higher risks of developing mesothelioma.

Eventually, physicians would establish that tradesmen that worked around asbestos were also exposed to enough to cause mesothelioma. Oftentimes in these cases, the disease would develop much later than those who worked in the mills or asbestos mines. Workers who built ships for the US Navy were often exposed to large amounts of asbestos because it was used to make naval ship more fireproof.

Conclusion

Even though asbestos as been perceived as dangerous since antiquity, it was not until the 1960s that physicians were able to confirm a link between asbestos and mesothelioma tumors. The tragedy is that there were numerous signs that working with asbestos was extremely dangerous before the Wagner paper was published in 1960. The dangers of asbestos could have been mitigated, but asbestos's so-called "magical properties" were still valued by modern society. Therefore, the discovery was hampered because some physicians argued that malignant pleura tumors did not exist and despite strong suspicions that asbestos dangerous. Additionally, the asbestos industry had little interest in tracking down why their miners and mill workers became ill. Eventually, a group of physicians in South Africa were finally able to put the pieces together and establish a firm link between asbestos exposure and mesothelioma.

Related DailyHistory.org Articles

• Social History of American Medicine Top Ten Booklist
• What was the dominant medical sect in the United States during the 19th Century?
• How did Medicine develop in the Ancient World?
• How Did Hospitals Emerge?
• How did Medicine develop in the Ancient World?
• How did illegal abortions spur the push for medical licensing in the 19th Century?