Coal has a long history of use as a vital energy source. After all, it was coal which powered the Industrial Revolution, propelling mankind into the modern age. Coal, though, has a dirty little secret. Along with its myriad benefits it carries a sting in its tail – and that sting is contained in its dust. Coal dust, the fine powder formed by the crushing of coal, can be lethal to both humans and the environment.
Coal mine dust is created when coal is crushed, ground or pulverized. It may also form when rain washes over a pile of coal. The dust is a mixture of 50 substances, including kaolinite, illite, calcite, pyrite and quartz. Mineral content is dependent upon the size of the dust particle and the seam of the coal. Mining exposure to coal dust occurs most frequently during the extraction process, but can also occur during cleaning, blending and transportation.
Coal Dust Dangers
How Does Coal Dust Affect Environment?
Air Pollution: Coal trucks and trains release coal dust into the air, degrading air quality and exposing local communities to unsafe levels of particulate matter (PM), methane, sulfur dioxide, nitrogen oxides and carbon monoxide. This can lead to severe and potentially lethal respiratory problems.
Soil Pollution: Coal dust released into the atmosphere will seep arsenic, lead, mercury, chromium, nickel and selenium into soil. These compounds can enter the food chain through microorganisms and plants. Once inside the human body they can lead to nerve damage, allergic reactions and reduced sperm count.
Water Pollution: Widespread concentrations of coal dust have been found on the surface of waterways located close to Coal Terminals. Tidal currents can carry the dust into the sea with resultant harm to flora and fauna living on the sea bottom. Coal dust in the water can lead to acidity, salinity, trace minerals and macronutrient buildup.
Coal Dust Explosions: Coal dust suspended in the air is highly flammable. When kept in an enclosed space, it has a greater surface area per unit of weight than coal in lump form, making it more susceptible to spontaneous combustion. The worst such explosion occurred at Benxihu Colliery, China in 1942, when 1,549 mine workers were killed.
It is important to note that susceptibility to the conditions noted above are not limited to people who directly handle coal. People living in mining communities are also at risk.
How Does Coal Dust Affect Health?
Coal dust is a powerful destroyer. The particles are microscopic but the impact on health is devastating. These are several of the most common diseases caused by coal dust.
Coal Workers Pneumoconiosis (CWP): The word Pneumoconiosis was coined in the 1870’s and means dusty lung. The condition is also known as Black Lung. It has been the blight of every coal mining family for the past 300 years. The condition is characterized by inflammation and scarring of the lungs caused by the ingesting of the dust into the lungs faster than the ability of the lungs to expel it. Coughing and shortness of breath are the immediate symptoms. Continued exposure can lead to the most severe form of the condition which may increase the likelihood of lung cancer, respiratory failure and cardiovascular impairment.
Silicosis: Rock formations that contain coal often include crystalline silica, which mixes with the minerals in the coal and forms part of the dust particle. As a result, exposure to coal dust can lead to silicosis, where fibrotic nodules and scarring occurs on the lung. Breathing impairment and death may result.
Chronic Obstructive Pulmonary Disease (COPD): Chronic bronchitis and emphysema are the two most common evidences of COPD.
Coal Dust Control
Or, What Can We Do?
Coal Dust contamination is a major environmental health problem. In the State of Washington, USA, 120 tons of coal is lost as dust every single day. Mining companies are finally being held accountable for their coal dust containment practices. Fortunately, a number of companies are taking a proactive stance in this regard. The following containment practices will help to reduce the dangers of coal dust contamination.
Sealant: A water based product with the same ingredients as found in white school glue is sprayed over the coal, creating a covering to trap the dust. This process is being used in conjunction with a low profile loading technique by Pacific Northwest coal exporter Peabody Energy as it loads coal onto railway cars.
Rail Car Covers: Several companies have been working on a range of rail car cover designs specifically designed to prevent the escape of coal dust. Global One Transport from Fort Worth Texas have patented full length retractable doors that contain the dust without slowing down the loading or dumping process. Ecofab Covers have designed a semi-rigid arched cover which is hinged on one side. Both of these innovations are promising moves in the fight against coal dust.
Rock Dust: Milled limestone, or rock dust, is an additive made from high quality natural ores that is mixed with coal dust. The compound is sprayed onto the roof, ribs and floor of the mine. The application reduces the likelihood of explosion and lung contamination. Carmeuse Lime and Stone, out of Pittsburgh, Pennsylvania are world leaders in the production and application of milled limestone.
High Tech Dust Suppressions Systems: High powered fans are installed with the ability to emit constant sprays of water over coal deposits.
Monitoring / Planning Loading Activity: By carefully planning loading operations to account for wind conditions, using CCTV to monitor wagon tops for residual loss of dust, being proactive in halting loading activities if unsafe dust levels are detected, reducing bulldozer activity to prevent coal disturbance and only accepting washed coal, the Port of Brisbane are leading the way in the Australian coal dust containment effort.
General Electric’s PowerTreat Technology: GE have developed a line of products specifically designed to mitigate the effects of coal dust contamination. These include foaming agents which expand to provide coal coverage with the addition of moisture, anti-oxidants and dust control binders.
The Worldwatch Institute blames 1.5 million deaths each year on coal dust contamination. As we’ve seen, the technology to combat coal dust exists and is being utilized by some. Legislation and social conscience are finally compelling stakeholders in the coal industry to take the dust issue seriously.
Lana Wilde, the author of this post, believes that unless we all take part in environment and planet preservation, soon there will be nothing to preserve. And no one to preserve it, consequently.
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