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Those Things’ll Kill You: Airborne Particulates

By Brian McFadden

Airborne dust, or particulates, can be a problem at a variety of worksites. Inhaling these particulates can cause effects from an annoying cough or two all the way to life-altering sickness like chronic bronchitis or cancer. As a result, people have tried to limit their exposure to dust in the workplace in a variety of ways.

Some drilling sites have sprayed water over the affected area, turning the dust into mud that stuck to the walls, floors, equipment, and workers. In the American Old West, there was even a fashion of growing “miner’s mustaches” to filter out dust, which was a distinctive approach, if not a particularly effective one. Some approaches to reducing dust have been more reliable than a bushy mustache—but some have been useless. In order to protect workers effectively, you need a detailed understanding of what you’re trying to protect them from. Three commonly-recognized particulate threats are silica dust, coal dust, and asbestos.

Silica Dust

Silica is one of the most common elements on our planet’s surface. It is frequently raised as clouds of dust during mining, sandblasting, construction, and excavation. Once those tiny, gritty particles are inhaled, they get stuck in the lungs, and the body has no way to get rid of them. Over time, the buildup of silica makes it difficult for lungs to work normally, leaving the victim constantly short of breath.

If that buildup was the end of the problem, it wouldn’t be so bad, but there’s more. The human body uses natural inflammation and immune responses to try and clean up, but they only make the problem worse. The name of this condition is “silicosis,” which reflects its origins. If allowed to continue, the condition slowly fills the lungs with scar tissue (a process called “pulmonary fibrosis”). Once silicosis develops this far, the only effective treatment is a lung transplant; otherwise, the victim will eventually suffocate.

Silicosis is rare in modern America, because of widespread awareness in the affected industries, and because of the availability of respirators and other modern tools that limit the inhalation of harmful dust. However, this has not always been the case. Miners in the Old West used picks, shovels and dynamite in “dry” mining processes, raising huge clouds of dust in their search for silver and gold; in spite of the “miner’s mustaches,” many of them died. The 1930 construction of the Hawk's Nest Tunnel in West Virginia resulted in at least 400 (by some estimates, well over 1,000) deaths from silicosis. And even today, parts of the world with poor working conditions still have widespread silicosis and early death.

Coal and Carbon Black

As a result of global industrialization, most urban areas of the world feature some degree of air pollution. Practically everyone who lives in a city has some slight degree of “anthracosis,” a progressive buildup of coal dust, soot, and other fine carbon-based material (“carbon black”) that collects in the lungs. For most urbanites, this never develops into a real problem. The carbon particles aren’t as hard and sharp as silica, so they don’t prompt the same degree of scarring and inflammation, and the human body can tolerate a little gunk here and there. But for people who are occupationally exposed to coal, the relatively harmless anthracosis can develop into Coal Workers’ Pneumaconiosis (CWP), more commonly known as “black lung disease.”

The long-term risks of CWP weren’t understood until well after silicosis was recognized as a major threat, and even in the coal mining industry, it used to be silicosis that people worried about most. It wasn’t until 1969 that the Federal Coal Mine Health and Safety Act was passed into law to reduce coal dust exposure for affected workers. Since then, we’ve continued to learn more about the issue. For example, underground mine workers were once thought to be the only ones with any real risk of developing black lung disease, but a 2010-2011 study by the National Institute for Occupational Safety and Health (NIOSH) showed that surface coal workers also showed signs. Fortunately, existing tests can identify victims even before any symptoms appear, so protective measures can be installed or improved in time to save lives.

Asbestos is Worst-os

Asbestos is probably the most well-known hazardous particulate. It may be hard to believe, but at one point the word “asbestos” didn’t mean “lawsuit.” From potholders to decorative (and fire-resistant) stucco, the material was used in thousands of applications that were considered safe and beneficial. The problems came up decades after the victim was exposed, and most inhalation exposures happened as the material was mined, processed, or broken down, not during ordinary use of the finished product. With such a long delay, it’s no wonder the hazards weren’t widely recognized until the 1920s.

Silica particles are so damaging to the lungs because they’re sharp and uncomfortable, and the human body can’t get rid of them. Asbestos fibers are just as difficult for the body to eliminate, and instead of just being small and sharp, the fibers tend to split lengthwise into thinner and thinner fibers. Once it gets frayed enough, asbestos can pierce individual cells. The body’s best protective response against this damage is to slowly build layers of “packaging” around each fiber, like a pearl forming around a grain of sand. But this is inside a lung, where there’s not much extra space for pearls! In addition to this effect, asbestos has been tied to several types of cancer, including mesothelioma. And just like the human body can’t seem to break it down, the ordinary outdoor environment doesn’t do much to asbestos; once it’s there, it tends to stay there.

If Not Mustaches, Then What Can We Trust?

There must be some steps that you can take to protect yourself and your coworkers from particulates. The “miners’ mustache” may not be helpful, but there are other steps that will help. OSHA’s priorities for facilities with airborne particulates focus on eliminating the hazard first, then protecting each employee individually if necessary.

For example, OSHA recommends enclosing a potentially hazardous area, providing appropriate ventilation, and substituting less dangerous working materials when available. If these steps are not enough, respirators may be required. To protect workers against particulates, OSHA requires either “atmosphere-supplying” respirators (which offer a breathable air supply separate from the working environment) or “air-purifying” respirators (which filter out unwanted material) that have been properly certified for use with the material in question. With appropriate workplace preparation and employee protection in place, airborne particulates won’t be a problem anymore. And that will be a breath of fresh air.