After water, concrete is the most widely used material on Earth, and millions of people work with it every year in this country. Unfortunately, inhaling concrete dust can cause serious and even fatal diseases such as silicosis, COPD (chronic obstructive pulmonary disease), and lung cancer because it usually contains silica. Learn the facts about concrete dust and the silica it contains so you can better protect yourself and your loved ones.
What is Silica?
Silica, also known as silicon dioxide, is one of the most common minerals on earth. In nature, crystalline silica often takes the form of quartz or sand. Silica is contained in many building materials such as concrete, masonry, mortar, bricks, concrete blocks, artificial stone, and countertops. OSHA estimates that about 2.3 million workers may be exposed to silica in their jobs, and that as many as 100,000 workers may be in high risk jobs such as construction.
Is Silica Dangerous?
Crystalline silica is not toxic unless there are airborne particles small enough to be inhaled deep into the lung. These respirable particles are much smaller than a grain of sand. In fact, they are so small that they are not visible to the naked eye, so even if you cannot see concrete dust, you may still be at risk. If you CAN see visible dust in the air, however, the amount of invisible, respirable particles is probably too high. Levels of airborne dust can remain high for some time after cutting, grinding, sweeping, and similar activities have stopped.
Inhaling respirable crystalline silica can cause silicosis, a scarring of the lungs that results in reduced lung function and makes you more vulnerable to infectious diseases such as tuberculosis. Silicosis is a progressive, irreversible disease with no known cure. According to the Centers for Disease Control (CDC), as many as 16,000 people died from silicosis in the United States between 1968 and 2002.
Airborne, respirable crystalline silica has been recognized as a human carcinogen which causes lung cancer by various agencies, including IARC (International Agency for Research on Cancer), the National Toxicology Program, and OSHA. The American Cancer Society also recognizes that crystalline silica can cause lung cancer.
There is growing evidence that silica can damage the kidneys and cause autoimmune diseases such as lupus and scleroderma. All of these diseases are incurable, so the only way to protect workers is to minimize their exposure to airborne silica through engineering controls (such as ventilation), good work practices (such as wetting down dust), and personal protective equipment (such as respirators) when needed.
Can Working with Concrete Expose Me to Silica?
Most concrete contains silica because of the sand which is added to the mix. Workers can be exposed to silica when dust becomes airborne during the concrete manufacturing process. Silica dust can also be released in large amounts when concrete is jack hammered, cut, sawed, milled, ground, crushed, chipped, or drilled; when broken concrete is cleaned up; or when tools and equipment are cleaned with compressed air instead of water. The more concrete dust you inhale, the greater the risk that you will develop a silica related disease.
The current NIOSH REL (Recommended Exposure Level) for respirable crystalline silica is 50 micrograms per cubic meter of air as a time weighted average. NIOSH studies have shown that much higher levels than this of airborne silica can be generated when concrete slabs are drilled so that dowel bars can be inserted to connect adjacent slabs in highways and runways. These studies have documented respiratory exposure levels up to 26X higher than the NIOSH REL during full depth pavement repair, and up to 8X the NIOSH REL during new runway construction. Studies have also found high levels of silica dust generated when highway concrete was jackhammered, sawed, milled, or cleaned up. A 2001 NIOSH study found very high levels of airborne dust containing silica when workers ground concrete to smooth poured surfaces after forms were stripped.
What Can I do to Protect Myself From Concrete Dust?
There are many things you can do to reduce your exposure to silica from airborne concrete dust, such as:
- Use the proper tools and keep them in good repair. Many power tools now have features designed to minimize airborne dust. For example, there is equipment that provides water to the blade or grinder when sawing or grinding concrete.
- Use appropriate personal protective equipment when needed such as NIOSH approved respirators. Paper dust masks provide little or no protection against respirable crystalline silica.
- Avoid eating, drinking, or smoking in dusty areas
- Washing your hands and face before eating, drinking, or smoking outside dusty areas
- Parking cars where they will not be contaminated with dust
- Changing into disposable or washable clothes at the job site
- Do not clean work clothes by brushing or blowing dust off
- Showering and changing into clean clothes before leaving the job site
- Using water spray systems and proper ventilation in confined areas
- Avoiding work in dusty areas when possible. Just working close to someone who is generating airborne dust can increase you exposure.
- Smoking adds to the lung damage caused by silica exposure, so if you smoke stop.
Contact Us For a Free Initial Consultation
If you or a loved one has been seriously injured because of your exposure to concrete dust, please contact us for a free initial consultation at 304-347-5050 (local) or 877-341-2595 (toll free). You can also contact us through our website, www.jfhumphreys.com.
NIOSH, Workplace Solutions: Control of Hazardous Dust When Grinding Concrete, April 2009
William D. Palmer, Jr., Protecting Your Crew From Silica Dust and Lead, Concrete Décor, Vol. 10, No. 5, July 2010 available online at https://www.concretedecorarticles/vol-10-no-5-july-2010/green-matters-protecting-your-crew-from-silica-dust-and-lead/
OSHA Pocket Guide, Workers Safety Series, Concrete Manufacturing, OSHA 3221-12N 2004, available online at https://www.osha.gov>Publications/concrete_manufacturing.html
NIOSH Publication No. 96-112 (1996), Preventing Silicosis and Deaths in Construction Workers, available on line at https://www.cdc.gov>niosh>docs
Silicosis: What it is and how to avoid it, Safety & Health, The Official Magazine of the NYS Congress & Expo, June 29, 2015, available on line at https://www.safetyandhealthmagazine.com
Valiente, Schill, Rosenmann & Socie, Highway Repair: A New Silicosis Threat, Am J Public Health, 2004 May 94(5): 876-80, available on line at https://www.ncbi.nih.gov>pmc>articles>PMC1448352
OSHA, Frequently Asked Questions on the New Silica Standards, https://www.osha.gov/dsg/topics/silicacrystalline/background_info_silica.html
Reducing hazardous dust exposure when dowel drilling in concrete, NIOSH Publication No. 2015-2000 available on line at https://www.cdc.gov>niosh>docs>wp-solutions>pdfs