Asbestos refers to a family of magnesium-silicate mineral fibres that can become inhalable and respirable when disturbed, leading to diseases such as asbestosis, mesothelioma and lung cancer. There are two main forms of asbestos namely serpentine and amphiboles. Asbestosis is the formation of scar tissue because of encapsulated fibres in the lung from respirable asbestos fibres that damage the cells of the lungs.
Silica is a naturally occurring substance that consists of the two most abundant elements in the earth’s crust; silica and oxygen. There are two forms namely crystalline and amorphous. Silicosis is a lung disease caused by inhalation, retention and pulmonary reaction to crystalline silica and when it becomes symptomatic, the primary symptom is difficulty in breathing and shortness of breath.
Are there any similarities between asbestos dust and silica dust? Yes! – they both contain crystalline silica specifically quartz and cristobalite. Therefore, both asbestos and silica are dangerous to human health as occupational exposure can result in asbestosis and silicosis. No amount of asbestos or silica exposure is safe, it is important to control respirable and inhalable asbestos and silica dust at its source to save lives. In this article, we compare asbestos vs silica based on the following discussion points:
- Asbestos vs silica – sources and origins.
- Asbestos vs silica – activities that generate airborne dust.
- Asbestos vs silica – dust control techniques.
Asbestos vs silica – sources and origins
Asbestos is a group of six fibrous, silicate minerals belonging to the serpentine (chrysotile – white asbestos) and amphiboles (amosite (brown asbestos), crocidolite (blue asbestos), tremolite, anthophyllite and actinolite) from most common to rarest classes. Serpentine fibres are curly and pliable. Amphiboles are thin, rod-like fibres and are considered the most carcinogenic. There are certain other minerals that are considered as asbestiform but the six named are the most common and therefore mostly found in use. Chemically, asbestos minerals are silicate compounds, meaning they contain atoms of silicon and oxygen in their molecular structure. All forms of asbestos are carcinogens according to National Institute for Occupational Safety & Health (NIOSH) and the World Health Organization (WHO). Silica consists of one atom of silicon and two oxygen atoms. In the crystalline state, silica molecules form a three-dimensional repeating pattern whereas in the amorphous state the silica molecules form a random pattern. Crystalline silica is found in almost every type of rock as quartz is the second most common form of the naturally occurring mineral. Volcanic rocks (granite ~ 33% quartz), sedimentary rocks (sandstone ~ 80% quartz) whilst sand and silt (~ 95% quartz). The health hazards of silica dust include silicosis, chronic obstructive pulmonary disease (COPD), lung cancer, kidney disease and autoimmune diseases such as rheumatoid arthritis. So, what are the activities that generate airborne asbestos or silica dust?
Asbestos vs silica – activities that generate airborne dust
How dangerous is broken asbestos? – it depends on whether the asbestos fibres are easily released. A broken piece of asbestos pipe insulation or damaged popcorn ceiling is friable and crumbled easily, and the tiny, microscopic asbestos get airborne easily. Broken asbestos floor tile or glue or roofing patch are non-friable materials, hence it is much harder for the fibres to get airborne, even if the material is broken up into small pieces. Other materials like cement asbestos pipe or asbestos cement roofing or siding or smoothing compound of drywall lie in between and how hazardous a broken piece is depending on how badly damaged it is and what circumstances there are to distribute the asbestos dust.
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The type of asbestos also makes a difference as has been alluded to in the sources and origins section. Asbestos can stay in the air almost indefinitely if there is air movement to keep it airborne. It can also settle on the surface of the soil instead of getting absorbed into the ground, which means that it can still get picked up by the wind and inhaled into human lungs. The industries at risk include carpentry, plumbers, roofers, plasterers, mechanics, miners, construction and maintenance workers who might have repeated and long-term exposure.
Silica dust forms during road and building construction, sandblasting, stone cutting, mining, abrasive manufacturing, glass manufacturing, quarrying, tunnelling and working with certain metal ores. Materials that contain crystalline silica are not hazardous unless they are disturbed, generating small-sized particles that can get in your lungs as respirable crystalline silica. Activities such as blasting, cutting, chipping, drilling and grinding materials that contain silica can result in silica dust that is hazardous for mining and quarry industries. In agriculture cultivation of arable land can cause significant exposure to respirable crystalline silica dust, the level of exposure will depend upon the concentration of crystalline silica in the soil type. In the construction industry, crystalline silica comes from materials such as concrete, mortar, bricks, tiles, stone and cement products. So what dust control techniques are available to deal with asbestos dust and silica dust?
Asbestos vs silica – dust control techniques
To understand dust control techniques, it is important to first answer how far can asbestos dust fibres go. They can be blown as far as the wind or building ventilation will take them. That’s why dust control at the source is very crucial to secure or stop further movement of the dangerous asbestos dust fibres.
GRT: Rubble-Loc is a cost-effective dust and wind erosion control technology designed for use on dynamic sites such as demolition and natural disaster sites that have the risk of generating asbestos, dust fibres. The product is diluted with water and best added with agitation or into flowing water to ensure thorough mixing. GRT: Activate can also be added to water used in wetting down sites, or sprayed through misting or fog cannons – making water work!
Drilling activities generate silica dust (and also asbestos fibres that may be naturally present in the rock) and to deal with respirable crystalline silica at its source, GRT: 12X super-activates water enabling it to saturate and capture the fine, hazardous dust drilling can generate, thus preventing it from becoming an airborne hazard. In blasting operations, workers on the drill pattern are exposed to silica dust – GRT: DC Binder crusts over drill cutting mounds and surrounds, locking down the fine respirable silica dust. Silica dust is generated from the hauling of different materials at the different sites therefore there needs to be haul road dust control.
GRT: Haul-Loc a liquid polymer can be added to the watering trucks upon which on spraying it binds fugitive dust particles preventing them from being airborne silica dust. On surfaces that are heavily trafficked and generate silica dust, waterless GRT: Wet-Loc can be used. Material handling generates silica dust and GRT: Activate can be used to suppress silica dust by wetting the material to optimal moisture content, preventing silica dust fines from being carried off into the air.
The lesson
Any amount of asbestos dust or silica dust is too much. Taking exposure lightly is gambling with lives and GRT commits to saving lives through the provision of asbestos and silica dust control products. Are you gambling with your worker’s lives?
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REFERENCES
About asbestos. Retrieved 08/07/21.
Asbestos and health risks. Retrieved 08/07/21.
Asbestos in the home. Retrieved 08/07/21.
Workplace Health Without Borders – Respirable Crystalline Silica. Retrieved 08/07/21.
