Mortar and Asbestos Exposure

Summary

For centuries, bricklayers and stonemasons built terrific structures by hand.  Masons worked with natural products like granite, sandstone and marble. Bricklayers specialized in materials like kiln-fired and sunbaked bricks.

Some craftspeople crossed between the two trades, but what every mason and bricklayer had in common was using mortar. And from the late 1800s to the 1980s, almost all mortar mixed by American stone and brick builders contained lethal amounts of asbestos.

Mortar acts as the bonding agent or glue for brick and stone construction. Builders utilized thousands of tons of asbestos-based mortar in every type of American building. That ranged from simple homes to public buildings and from factories to churches and hospitals. Over a million American public buildings contain asbestos mortar. Millions of private homes have asbestos mortar on their facades, in the fireplaces and up their chimneys.

Asbestos seemed like an ideal material for mortar making. When bricklayers and stonemasons added an asbestos powder to their mortar, the tensile strength of their work enormously increased. Asbestos was a light additive that reduced mortar weight by half. Mortar made with asbestos fibers became fireproof and acted as a thermal break for insulation. An asbestos mortar was easy to work with, non-corrosive, didn’t conduct electricity, stayed chemically inert, was in plentiful supply and offered superior cost-effectiveness.

Asbestos Fibers in Brick and Masonry Mortar

Adding asbestos to mortar had other perceived benefits. Asbestos fibers flowed well in mortar mixes and stayed stable during hot and cold working environments. Mortar containing asbestos particles had a controlled set rate allowing workers more placing time with larger batches. A lot of heat control and setting time variables depended on the type of asbestos fibers used in mortar.

There were two main types:

  • Chrysotile asbestos fibers: These were abundant in masonry and brick mortar. Chrysotile was also called “white asbestos” or “good asbestos” due to well-known side effects of breathing asbestos dust particles. They’re classified as serpentine asbestos forms because when viewed microscopically, chrysotile fibers appear curvy or serpent-like. Chrysotile fibers are also softer and less harmful to lungs that the other asbestos class used in mortar.
  • Amphibole asbestos fibers: These are much harder and sharper. Microscopically, amphibole fibers look crystalline with tiny needles protruding from the particles. Amphibole asbestos came if blue, green and brown colors. The most common amphibole subclass used in mortar mixes was tremolite. This amphibole asbestos fiber class stood high temperatures well and proved exceptionally strong.

Masons and bricklayers knew their asbestos additives’ behavior. They blended different types of asbestos fibers into cement mortar to give high strength and fire resistance where needed. Furnaces, fireplaces, chimneys and flues contained high ratios of amphibole fibers compared to chrysotile particles. Four parts of amphibole to one part chrysotile were common. Overall asbestos content in a mortar mix often exceeded 80 percent for high-temperature applications.

Mortar and Asbestos Exposure

MJN Brief

Everyone who worked with or around mortar containing asbestos was at risk of inhaling airborne asbestos fibers. That included workers in factories manufacturing bricks and dry mortar powder. Masons and bricklayers who blended mortar containing asbestos materials were at high exposure risk. So was everyone in the vicinity where asbestos particles from mortar were mixed.

Other airborne asbestos fiber exposure risks occurred when mortar became old and crumbly. This decay is called a friable state where corrosion, long-term heat and natural breakdown from age turned cured mortar into flakes and dust. Demolition and renovation contractors were at high risk of asbestos exposure when they dismantled old brick and stone structures causing mortar to destruct and become friable.

Inhaling microscopic asbestos fibers causes tiny particles to stick in the lung lining which is called the mesothelium. Amphibole asbestos fibers are far worse for embedding than chrysotile fibers. That’s because of the hard, sharp spines that easily puncture the mesothelium, whereas chrysotile fibers are smoother and softer.

Regardless which type of asbestos fibers impaling the mesothelium, they can’t be expelled. Asbestos particles remain in the lungs forever and build up scar tissue. It may take up to 50 years, but these masses eventually turn tumorous and become the incurable cancerous disease called mesothelioma.

Compensation for Mesothelioma Victims

Although there’s no cure for advanced mesothelioma, compensation is available for victims who developed mesothelioma from workplace asbestos exposure. It is possible to receive compensation for personal injury damages, lost income and medical expenses. Families of mesothelioma victims can claim on members’ behalf. They can also file lawsuits in wrongful death cases.