Although there is a small chance that the cancer known as mesothelioma may have other causes (currently being studied), the only known and proven cause – and certainly the most common one – is asbestos exposure. Many occupations carry a risk of such exposure, and those who work at construction trades – including bricklayers – are at the greatest risk of all.
Asbestos is the generic name given to a number of silicate minerals that were used in building and ship construction for decades because of their unique, fire-proof and heat-resistant characteristics. These characteristics are due to the fact that asbestos minerals are literally made of stone or rock. Unlike most stone however, asbestos-type minerals are soft and pliable like cotton, and therefore can be woven into cloth, made into sprays and made into insulation.
Materials Containing Asbestos
Blast furnaces and firing kilns are regularly heated to temperatures ranging from 2000 to 3200 degrees Fahrenheit. Under such conditions, normal brick would crack because the inability of the material to conduct heat evenly and effectively; regular mortar is prone to explode under such conditions because of its porous nature. Therefore, special “fire bricks” and mortar were required for such applications.
Because of its fire resistance, asbestos was a common ingredient in the manufacture of fire bricks, used to line such furnaces, and even fireplaces, as well as the mortar used to bind them together.
Chrysotile is the most common type of asestos used in building and home construction. Also known as “white asbestos,” it is somewhat softer than other types and has less tensile strength. These fibers have a curly shape, like microscopic springs. Because of this, chrysotile was considered “safer” than other types of asbestos.
Serpent in the Stone
It is now known that chrysotile was in fact not safer than other types of asbestos. Also known as serpentine, chrysotile fibers were extensively mined in the U.S., Canada and the former Soviet Union. When inhaled or ingested, these fibers have been known to find their way into every part of the body, including the brain and the heart. They burrow into the soft tissues of the inner lungs. Interestingly, anti-bodies actually recognize these fibers as pathogens (“foreign invaders” or a potential source of infection). The problem is that antibodies are designed to attack organic invaders. Asbestos fibers are inorganic; antibodies actually tear themselves apart trying to attack these fibers, causing their digestive molecules to spill onto healthy tissues, leading to the formation of scar tissue. This is what causes asbestosis.
Pleural Mesothelioma It is not known for certain how asbestos fibers cause cancerous cells, such as in the case of the rare asbestos cancer mesothelioma, to develop. It is known that such fibers can burrow through the lungs and become lodged in the outer pleural lining, causing it to harden. Medical researchers believe that interaction between asbestos fibers and living tissues causes mutations in the victim’s DNA, leading to the formation of tumors.
A Potential Time Bomb
Malignant mesothelioma is an aggressive, highly malignant form of cancer that attacks the pleural lining (outside layer) of the lungs in its most common form of pleural mesothelioma, and other organs in orther, more rare, forms. The latency period is quite long; symptoms may not appear until forty years after initial exposure.
If you worked as a bricklayer prior to the mid 1980s, it is important to have regular screenings for respiratory illness; like most cancers, mesothelioma is most treatable when caught in the early stages.