tag:theconversation.com,2011:/au/topics/black-lung-23105/articlesBlack Lung – The Conversation2018-02-16T11:41:49Ztag:theconversation.com,2011:article/916372018-02-16T11:41:49Z2018-02-16T11:41:49ZBlack lung disease on the rise: 5 questions answered<figure><img src="https://images.theconversation.com/files/206620/original/file-20180215-131032-1ufco25.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Coal miner Scott Tiller works next to a drill in an underground coal mine roughly 40 inches high in Welch, West Virginia.</span> <span class="attribution"><a class="source" href="http://www.apimages.com/metadata/Index/Divided-America-American-Moments/1a2120a4c93045849281476fcbf7a72c/88/0">AP Photo/David Goldman</a></span></figcaption></figure><p><em>Editor’s note: An <a href="http://dx.doi.org/0.1001/jama.2017.18444">article</a> published Feb. 6, 2018 in the Journal of the American Medical Association reported that researchers from the <a href="https://www.cdc.gov/niosh/">National Institute for Occupational Safety and Health</a> had identified 416 cases of advanced black lung disease among coal miners in central Appalachia. New cases of black lung had been rare until recently, but this study suggests that the incidence is rising. Anna Allen and Carl Werntz, professors of occupational medicine at West Virginia University who treat miners with black lung, explain what causes this disabling disease.</em></p>
<h2>1. What is black lung disease, and what causes it?</h2>
<p>Underground mining is <a href="https://www.bls.gov/iif/oshwc/osh/os/osar0012.htm">one of the most dangerous occupations</a> in the United States. Risks include inhaling toxic gases, such as methane, carbon monoxide and hydrogen sulfide; being crushed by roof falls or mining equipment; drowning when tunnels fill with water; and injury in fires and explosions. Even if miners survive the workplace, they may suffocate to death years later.</p>
<p>Surface and underground mining is associated with two pneumoconioses, or dust diseases of the lung. Black lung disease, also known as coal workers’ pneumoconiosis, comes from inhaling coal mine dust. The other disease, silicosis, is caused by inhaling silica dust from crushed rocks. Black lung and silicosis often appear together because coal seams are found between rock layers that contain silica.</p>
<p>When miners inhale dust, it deposits along their airways. Their bodies try to remove the dust by sending in special white blood cells called <a href="https://askabiologist.asu.edu/macrophage">macrophages</a> to engulf and chemically digest it. But the cells are unable to break down the dust, so they die and release enzymes that damage lung tissue. This causes problems that include chronic bronchitis, emphysema and fibrosis (scarring). In progressive massive fibrosis, the most severe version of black lung, scarring causes lung volume to shrink, further damaging adjacent lung tissue and making air exchange even worse.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/206607/original/file-20180215-131003-1tx9xsb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/206607/original/file-20180215-131003-1tx9xsb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/206607/original/file-20180215-131003-1tx9xsb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=515&fit=crop&dpr=1 600w, https://images.theconversation.com/files/206607/original/file-20180215-131003-1tx9xsb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=515&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/206607/original/file-20180215-131003-1tx9xsb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=515&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/206607/original/file-20180215-131003-1tx9xsb.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=647&fit=crop&dpr=1 754w, https://images.theconversation.com/files/206607/original/file-20180215-131003-1tx9xsb.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=647&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/206607/original/file-20180215-131003-1tx9xsb.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=647&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Coal worker’s lungs, with black pigmentation and fibrosis due to inhalation of carbon pigment and silica.</span>
<span class="attribution"><a class="source" href="https://flic.kr/p/8Ur4Ao">Yale Rosen</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span>
</figcaption>
</figure>
<p>Miners typically work 10 to 12 hours a day and up to seven days a week. This increases their exposure time and decreases the recovery time their bodies need to heal damage from silica and coal dust particles. Traditionally, black lung was associated with miners who had been working for at least 20 years, with symptoms often appearing after retirement. The recent trend is that black lung, including progressive massive fibrosis, is occurring after a <a href="https://www.cdc.gov/niosh/nioshtic-2/20044371.html">shorter time in mining</a> – as little as five years mining underground. </p>
<h2>2. Are you surprised by the large case cluster described in the JAMA article?</h2>
<p>The “hot spot” described in the JAMA study is in parts of western Virginia, southern West Virginia and eastern Kentucky. This area includes three of the federal <a href="https://www.msha.gov/about/program-areas/coal-mine-safety-and-health">Mine Safety and Health Administration</a> enforcement districts – areas where the agency inspects coal mines and investigates accidents and complaints from miners.</p>
<p>We see patients in Morgantown in north-central West Virginia and Cabin Creek in south-central West Virginia. We have noticed increased severity of disease in patients in the southern part of the state. During our first year, from June 2016 to May 2017, working in Cabin Creek providing federally authorized black lung exams, the incidence was 16 percent for black lung and about 6 percent for progressive massive fibrosis. In contrast, the same exams in our Morgantown clinic found black lung in less than 3 percent of cases, and only a few progressive massive fibrosis cases in four years.</p>
<figure class="align-right zoomable">
<a href="https://images.theconversation.com/files/206611/original/file-20180215-131013-273uc5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/206611/original/file-20180215-131013-273uc5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/206611/original/file-20180215-131013-273uc5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=594&fit=crop&dpr=1 600w, https://images.theconversation.com/files/206611/original/file-20180215-131013-273uc5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=594&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/206611/original/file-20180215-131013-273uc5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=594&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/206611/original/file-20180215-131013-273uc5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=746&fit=crop&dpr=1 754w, https://images.theconversation.com/files/206611/original/file-20180215-131013-273uc5.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=746&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/206611/original/file-20180215-131013-273uc5.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=746&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">In 1974 progressive massive fibrosis affected nearly 3.5 oercent of coal miners with 25 or more years of underground mining tenure. Rates dropped precipitously under new protective rules but have since rebounded.</span>
<span class="attribution"><a class="source" href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4710586/#r7">Environmental Health Perspectives</a></span>
</figcaption>
</figure>
<h2>3. What do you think could be causing more cases of black lung disease?</h2>
<p>The increase is likely the result of several factors. Much of the coal in the area of the JAMA study is so-called “low coal,” with seams that are only 20 to 36 inches high. This “low coal” is hard to mine but profitable because it is metallurgical coal, which has high value for steel production.</p>
<p>Manufacturers stopped producing shorter machines designed for mining “low coal” in about 1990 due to quality control problems. Now mines use taller machines designed for seams that are 32 to 36 inches high. As these machines cut coal from the seam, they must remove at least 12 to 16 inches of sandstone adjacent to the coal.</p>
<p>Cutting that much sandstone significantly increases miners’ exposure to silica dust from the crushed rock. Newer machines also cut through coal and rock much more quickly than older models, generating more dust. Generally, what we call black lung is primarily silicosis in a coal miner, so <a href="https://www.cdc.gov/mmwr/volumes/65/wr/mm6549a1.htm">silica exposure is significant</a> to the development and progression of disease.</p>
<figure>
<iframe width="440" height="260" src="https://www.youtube.com/embed/6AYZG5n2VUA?wmode=transparent&start=0" frameborder="0" allowfullscreen=""></iframe>
<figcaption><span class="caption">In this video a longwall mining machine can be seen spraying water to control dust.</span></figcaption>
</figure>
<p>Working in “low coal” also involves more physical effort than mining “high coal.” Crawling and stooping while carrying mining gear and operating equipment requires more physical effort. Miners breathe more heavily and frequently, which can increase dust exposure. And it is hard to keep air flowing smoothly through these smaller mines, so dust concentrations may be higher in some spots.</p>
<h2>4. What does the coal industry do to prevent black lung?</h2>
<p>Screening is available to current miners through the federal government’s <a href="https://www.cdc.gov/niosh/topics/cwhsp/cwhsp-xray.html">Coal Workers’ Health Surveillance Program</a>, which uses x-rays to detect early changes in the lungs. This information is shared with miners so they can decide whether to continue working in coal mining, but is kept private from their employers.</p>
<p>The main way to prevent black lung is to keep miners from inhaling dust. After <a href="https://www.npr.org/2012/07/10/155981916/black-lung-rule-loopholes-leave-miners-vulnerable">20 years of debate</a>, recent changes in federal law <a href="https://arlweb.msha.gov/endblacklung/docs/summaryEffectiveDates.pdf">decreased the allowed exposure</a> from 2.0 milligrams per cubic meter of air to 1.5 milligrams. Continuous personal dust sampling has also been implemented so that miners can have real-time data on their exposures. This information is then used to determine whether a mine requires more frequent inspections.</p>
<p>To decrease dust exposure, mine operators can spray water to knock dust out of the air, increase air flow in tunnels to move dust out more quickly, or require miners to wear respirators. </p>
<h2>5. What resources are available for miners who may have black lung?</h2>
<p>Black lung diagnosis can be complicated. Some of the most common symptoms include shortness of breath, decreased exercise tolerance, chronic cough, coughing up phlegm and inability to breathe lying flat. Other diseases can cause similar symptoms, so it is important for miners to talk to their primary care doctors. </p>
<p>Some states have workers compensation programs that offer benefits to workers diagnosed with black lung. The Federal <a href="https://www.dol.gov/owcp/dcmwc/">Black Lung Program</a> provides medical coverage for eligible miners with lung diseases related to pneumoconiosis, along with benefits for those who are totally disabled by it, and for families of miners who die of black lung disease.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/206601/original/file-20180215-131016-mrmlv6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/206601/original/file-20180215-131016-mrmlv6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/206601/original/file-20180215-131016-mrmlv6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=348&fit=crop&dpr=1 600w, https://images.theconversation.com/files/206601/original/file-20180215-131016-mrmlv6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=348&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/206601/original/file-20180215-131016-mrmlv6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=348&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/206601/original/file-20180215-131016-mrmlv6.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=437&fit=crop&dpr=1 754w, https://images.theconversation.com/files/206601/original/file-20180215-131016-mrmlv6.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=437&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/206601/original/file-20180215-131016-mrmlv6.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=437&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Mobile unit for providing coal miner health screenings.</span>
<span class="attribution"><a class="source" href="https://upload.wikimedia.org/wikipedia/commons/1/10/NIOSH_Mobile_Health_Screenings_%2816027817612%29.jpg">NIOSH</a></span>
</figcaption>
</figure>
<p>There is no cure for black lung disease – we can only treat symptoms. Medications, such as inhaled steroids, can help patients breathe more easily. More severe cases can require oxygen and possibly lung transplants. One step patients can take is to stop smoking, which also destroys lung tissue. Smoking does not cause black lung, but it can make the symptoms more severe.</p><img src="https://counter.theconversation.com/content/91637/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Anna Allen, MD, MPH, is the Associate Residency Director of West Virginia University Occupational Medicine, which is funded by NIOSH. She is currently working on a NIOSH funded project assessing PAPR usage in the healthcare setting. She is also on the board of the Association of Occupational and Environmental Clinics, which has advocated for worker safety and health. All opinions expressed in this article are the author's and should not be attributed to WVU or other affiliated organizations.</span></em></p><p class="fine-print"><em><span>Carl Werntz is a part-time employee of the National Institutes for Occupational Safety and Health, although he has not been involved with any of the research mentioned in this article. The findings and conclusions in this report are those of the author(s) and do not represent the official position of the National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention.</span></em></p>A recent study found the largest cluster of advanced black lung disease ever recorded among coal miners in central Appalachia. Two doctors who treat black lung patients explain how miners contract it.Anna Allen, Associate professor of Occupational Medicine, West Virginia UniversityCarl Werntz, Associate Professor of Occupational Medicine, West Virginia UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/804652017-08-07T02:09:55Z2017-08-07T02:09:55ZExplainer: what is silicosis and why is this old lung disease making a comeback?<figure><img src="https://images.theconversation.com/files/179579/original/file-20170725-6656-edt7nc.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">You can barely see this construction worker for dust. His lack of protective face mask puts him at risk of silicosis and other lung diseases.</span> <span class="attribution"><a class="source" href="https://commons.wikimedia.org/wiki/Category:Silicosis#/media/File:DustWorker.jpg">Lamiot/Wikimedia</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Silicosis is a group of occupational lung diseases caused by breathing in silica dust. It has been described since ancient times, when miners and stone cutters were exposed to dust containing this crystalline mineral.</p>
<p>Silicosis was more common in Australia in the 1940s to 60s, particularly in construction and demolition workers. Growing awareness of the disease and the importance of reducing exposure to dust – for instance, wearing masks at work, wetting the dust and other safe work practices – has reduced the number of cases.</p>
<p>However, there has been a worrying resurgence of cases recently, as a recent New South Wales parliamentary committee <a href="https://www.parliament.nsw.gov.au/committees/DBAssets/InquiryEventTranscript/Transcript/9950/Transcript%20-%2028%20June%202017%20-%20UNCORRECTED.pdf">has heard</a>. Now one of the fastest growing occupational groups we’re seeing with silicosis are people who <a href="https://www.mja.com.au/journal/2017/206/9/complicated-silicosis-resulting-occupational-exposure-engineered-stone-products">make and install engineered stone products</a>, the type of benchtops and tiles you might find in your kitchen or bathroom. </p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/australias-occupational-health-and-safety-regime-needs-first-aid-12794">Australia's occupational health and safety regime needs first aid </a>
</strong>
</em>
</p>
<hr>
<p>This resurgence in cases is likely related to a poor understanding of the risks involved in working with engineered stone, and a <a href="https://www.parliament.nsw.gov.au/committees/DBAssets/InquiryEventTranscript/Transcript/9950/Transcript%20-%2028%20June%202017%20-%20UNCORRECTED.pdf">lack of adherence to safety regulations and surveillance requirements</a>.</p>
<h2>What is silica and how are people exposed?</h2>
<p>Silica is in quartz, sand, stone, soil, granite, brick, cement, grout, mortar, bitumen and engineered stone products.</p>
<p>Any occupation disturbing the earth’s crust increases the risk of silicosis. That includes sand blasting, cutting, excavating, building on sandstone, demolition work, tunnelling, quarry work and mining. Air-polishing concrete, foundry work, bricklaying, stone masonry, and making glass and ceramics also increase the risk.</p>
<p><a href="https://academic.oup.com/annweh/article-abstract/60/5/631/2196173">About 6.6% of Australian workers</a> are exposed to crystalline silica dust that can be breathed in, and 3.7% are heavily exposed.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/180981/original/file-20170804-27426-1gis17k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/180981/original/file-20170804-27426-1gis17k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/180981/original/file-20170804-27426-1gis17k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/180981/original/file-20170804-27426-1gis17k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/180981/original/file-20170804-27426-1gis17k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/180981/original/file-20170804-27426-1gis17k.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/180981/original/file-20170804-27426-1gis17k.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/180981/original/file-20170804-27426-1gis17k.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Stone masons are also at risk from silicosis if they don’t take precautions against breathing in silica dust.</span>
<span class="attribution"><a class="source" href="https://www.shutterstock.com/download/confirm/341489507?src=kqnbp-yH_j46iZGl762w8g-1-48&size=medium_jpg">from www.shutterstock.com</a></span>
</figcaption>
</figure>
<p>While not all of these will go on to develop silicosis a significant proportion will, with symptoms appearing between months and many years after exposure, depending on the type of silicosis. </p>
<p>The likelihood of developing severe silicosis increases depending on how much dust people are exposed to and for how long. Genetics may also play a role in susceptibility, with some groups, <a href="https://academic.oup.com/aje/article/144/9/890/95225/Silicosis-among-Foundry-Workers-Implication-for">like African Americans</a>, having a higher risk.</p>
<p>Symptoms of silicosis include a cough, breathlessness and tiredness. But in the early stages of the disease, there may be no symptoms.</p>
<p>As silicosis can progress long after exposure at work, people should report any troublesome symptoms to their GP, even after they have left the industry. If silicosis is suspected, they should be referred to a respiratory physician.</p>
<h2>Different types of silicosis</h2>
<p>There are three different types of <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1637684/">silicosis </a>:</p>
<ul>
<li>acute silicosis can develop within weeks of very heavy exposure to silica. The lungs are filled with a fluid containing a lot of protein, which causes severe breathlessness</li>
<li>accelerated silicosis is also associated with high exposures (the type currently being seen in people working with engineered stone products), where there’s a rapid increase of scarring in the lung (fibrosis) within 10 years of first exposure, and</li>
<li>chronic silicosis, the most common form of silicosis, where fibrosis occurs more slowly over 10-30 years after first being exposed.</li>
</ul>
<figure class="align-right ">
<img alt="" src="https://images.theconversation.com/files/179575/original/file-20170725-11666-135if6g.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=237&fit=clip" srcset="https://images.theconversation.com/files/179575/original/file-20170725-11666-135if6g.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=584&fit=crop&dpr=1 600w, https://images.theconversation.com/files/179575/original/file-20170725-11666-135if6g.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=584&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/179575/original/file-20170725-11666-135if6g.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=584&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/179575/original/file-20170725-11666-135if6g.jpeg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=734&fit=crop&dpr=1 754w, https://images.theconversation.com/files/179575/original/file-20170725-11666-135if6g.jpeg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=734&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/179575/original/file-20170725-11666-135if6g.jpeg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=734&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px">
<figcaption>
<span class="caption">Chest x-ray of complicated silicosis, showing large areas of scarring.</span>
<span class="attribution"><span class="license">Author provided</span></span>
</figcaption>
</figure>
<p>Then there’s simple and complicated silicosis. Simple silicosis results in many small white spots (nodules) that you can see on a chest x-ray or CT scan. With complicated silicosis there are large areas of scarring called progressive massive fibrosis.</p>
<p>In general, the more scarring and the more widespread it is, the more trouble people have breathing as their lungs lose their capacity to expand and contract with each breath. Silicosis also increases people’s susceptibility to <a href="https://theconversation.com/explainer-what-is-tb-and-am-i-at-risk-of-getting-it-in-australia-75290">tuberculosis</a>.</p>
<h2>How is silicosis treated and what are the outcomes?</h2>
<p>Diseases due to silica exposure are serious and potentially lethal, and there is no specific treatment other than supportive care. This can include stopping smoking, using inhalers, vaccination against infections, and antibiotics. In the late stages, oxygen treatment or a lung transplant may be needed.</p>
<p>Once diagnosed, the disease generally progresses over time. Patients with accelerated silicosis may progress to progressive massive fibrosis over a period of four to five years. Overall, people diagnosed with silicosis lose an average 11.6 years of life. So, prevention is vital.</p>
<h2>How can we prevent silicosis?</h2>
<p>Diseases due to silica exposure – for instance silicosis, <a href="https://monographs.iarc.fr/ENG/Monograph">lung cancer</a>, connective tissue disorders like <a href="http://www.sclerodermaaustralia.com.au/about/about-scleroderma">scleroderma</a>, kidney disease and <a href="https://www.betterhealth.vic.gov.au/health/conditionsandtreatments/lung-conditions-chronic-obstructive-pulmonary-disease-copd">chronic obstructive lung disease</a> – are entirely preventable.</p>
<p>Wetting of silica dust, using appropriate exhaust ventilation and extraction hoods, and wearing the right dust masks and air filters all reduce the chances of someone breathing in silica dust at work.</p>
<p>There are also <a href="https://www.safeworkaustralia.gov.au/system/files/documents/1705/workplace-exposure-standards-airborne-contaminants-v2.pdf">workplace standards</a> on exposure to silica dust. And workplace screening for lung disease is <a href="https://www.safeworkaustralia.gov.au/system/files/documents/1702/guide-pcbu-health-monitoring-exposure-hazardous-chemicals.pdf">mandatory</a> for those at significant risk, which can include a physical examination as well as x-rays and lung function tests.</p>
<h2>How can we keep track of silicosis?</h2>
<p>Silicosis carries a high <a href="https://www.safeworkaustralia.gov.au/system/files/documents/1702/occupational_respiratory_disease_australia.pdf">social and economic cost</a>. And workers can receive compensation for silica-related disease in some states. In NSW, for instance, <a href="https://www.safeworkaustralia.gov.au/system/files/documents/1702/occupational_respiratory_disease_australia.pdf">186 workers</a> received compensation payments through the Dust Diseases Board in 2002-2003.</p>
<p>Yet, we don’t know the true number of new cases in Australia. While there are voluntary reporting systems in Victoria, Tasmania and NSW, these are likely to have underestimated the true incidence of disease.</p>
<hr>
<p>
<em>
<strong>
Read more:
<a href="https://theconversation.com/explainer-what-is-black-lung-and-why-do-miners-get-it-51649">Explainer: what is black lung and why do miners get it?</a>
</strong>
</em>
</p>
<hr>
<p>So specialist doctors concerned about the resurgence of silicosis <a href="https://www.parliament.nsw.gov.au/committees/DBAssets/InquiryEventTranscript/Transcript/9950/Transcript%20-%2028%20June%202017%20-%20UNCORRECTED.pdf">have called for</a> mandatory reporting of occupational lung disease to a centralised registry, as occurs in Europe and America.</p>
<p>Australia is seeing the re-emergence of diseases like silicosis and coal worker’s lung (also known as black lung) that were previously believed to have disappeared. So, workers, employers, doctors, public health officials, and legislators need to work together to prevent more cases of these deadly, but preventable, lung diseases.</p><img src="https://counter.theconversation.com/content/80465/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Susan Miles is a Staff Specialist at Calvary Mater Newcastle, and a Member of the Occupational and Environmental Lung Disease Special Interest Group of the Thoracic Society of Australia and New Zealand.</span></em></p>We’re seeing the resurgence of an old lung disease in people who make and install the type of engineered stone product you might find in your kitchen or bathroom.Susan Miles, Respiratory, sleep and general physician and conjoint lecturer in medicine, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/578172016-07-15T07:02:51Z2016-07-15T07:02:51ZWhy the health scheme for coal workers is inadequate to detect black lung<figure><img src="https://images.theconversation.com/files/130510/original/image-20160714-12386-1asgtze.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Radiologists will struggle to find black lung in x-rays if they haven't been told to look for it.</span> <span class="attribution"><span class="source">from www.shutterstock.com.au</span></span></figcaption></figure><p><a href="https://theconversation.com/black-lungs-back-how-we-became-complacent-with-coal-miners-pneumoconiosis-57718">Recent cases of black lung</a> in Queensland coal miners after many years of no known cases have raised important questions about control of dust exposure in coal mines, as well as the adequacy of medical screening to detect such cases at an early stage. </p>
<p>A <a href="https://www.dnrm.qld.gov.au/__data/assets/pdf_file/0009/383940/monash-qcwp-final-report-2016.pdf">review for the Queensland government</a> on the health assessment of miners has identified serious deficiencies at virtually all levels of the scheme.</p>
<p>Black lung is the commonly used name for <a href="http://www.ncbi.nlm.nih.gov/pubmed/23590267">coal workers’ pneumoconiosis</a>, which is a lung condition where inhaled coal dust <a href="https://theconversation.com/explainer-what-is-black-lung-and-why-do-miners-get-it-51649">causes scarring of lung tissue</a>. Black lung can cause severe symptoms including shortness of breath, heart problems and death, and so it is important to detect it early and reduce further exposure to coal dust. </p>
<h2>So what’s wrong with the Queensland coal miners’ health scheme?</h2>
<p>Our review found several major deficiencies. These include:</p>
<ul>
<li><p>a lack of appropriate training for doctors working within the scheme and a standardised process of deciding who should have chest x-rays</p></li>
<li><p>poor-quality tests to measure the functioning of the lungs</p></li>
<li><p>radiologists not being informed what they’re looking for in chest x-rays</p></li>
<li><p>inadequate data collection</p></li>
<li><p>a lack of clinical guidelines for when follow-up tests and specialist referral are necessary. </p></li>
</ul>
<p>The scheme also has limited ability for doctors to access previous medical findings. This makes it difficult to assess longitudinal changes.</p>
<p>Some criticism has been made of chest x-rays performed under the scheme, but this requires some further context. No-one doubts that radiological expertise is of a high standard in Australia, but the problem with chest x-rays being performed under the scheme is that the radiologists have not been notified that it is for screening of lung disease in coal mine workers. </p>
<p>The radiologists have not been specifically trained for the purposes of the scheme, nor have they used the specific ILO reporting form designed to identify early changes consistent with black lung.</p>
<h2>Why did this happen?</h2>
<p>A key original purpose of the health assessments was to identify early stages of black lung in any affected coal miners so that measures could be put in place to reduce coal dust exposure. In more recent years, this purpose has been lost. The prime focus of the health assessments has instead become a pre-employment medical assessment.</p>
<p>This loss of purpose has then influenced the operation of the scheme, as the doctors who do these medicals haven’t focused on identifying early signs of black lung, but on whether the mine worker can do the job. This is a completely different perspective. This shift of focus away from lung screening has had a negative influence on the operation of the various components of the scheme.</p>
<p>The mining boom in Queensland compounded the problems with the health assessment scheme. The rapid expansion of the coal industry meant a huge influx of mine workers in a short time. As a result, the demand for health assessments for coal mine workers increased greatly, and the capacity of the health assessment scheme and the doctors performing these medicals became very stretched.</p>
<p>Complacency also played a factor. There was a widespread belief that lung disease in coal miners was a thing of the past, based on the apparent lack of any black lung cases being identified by the scheme. But nothing could be further from the truth, as this disease is still a <a href="http://www.ncbi.nlm.nih.gov/pubmed/25052085">major problem in the US</a> and many other countries. Therefore it requires constant vigilance.</p>
<p>Another important consideration is that workplace exposure limits for coal dust in Queensland are <a href="https://theconversation.com/black-lungs-back-how-we-became-complacent-with-coal-miners-pneumoconiosis-57718">set higher than the more stringent levels</a> in many other countries, and even in other states of Australia. </p>
<p>A <a href="http://oem.bmj.com/content/67/12/801.extract">major problem in the effective control</a> of workplace diseases is exposure limits not in keeping with the latest evidence. This has been exemplified by the situation in Queensland coal mines.</p>
<p>Primary prevention of coal dust diseases, through the effective monitoring and control of coal dust, should be the main focus of prevention efforts in this industry. </p>
<p>Medical screening is a secondary prevention measure, which should be thought of as an adjunct to dust control, not a replacement for it. This is particularly important to remember for diseases with long latency periods from first exposure to disease onset, <a href="https://theconversation.com/explainer-what-is-black-lung-and-why-do-miners-get-it-51649">such as black lung</a>. The importance of focusing on dust control in coal mines was also an important conclusion of a recent <a href="http://www.aph.gov.au/Parliamentary_Business/Committees/Senate/Health/Health/Fifth_Interim_Report">Senate inquiry into coal dust</a>.</p>
<h2>Wider implications</h2>
<p>The findings of our review have important implications over and above the coal industry in Queensland and the coal mine workers’ health scheme. It is well known there is a <a href="http://www.ncbi.nlm.nih.gov/pubmed/?term=Purdue%20MP%5BAuthor%5D&cauthor=true&cauthor_uid=25487971">serious underestimate</a> of <a href="http://www.ncbi.nlm.nih.gov/pubmed/?term=Hutchings%20SJ%5BAuthor%5D&cauthor=true&cauthor_uid=25487971">cancer and other chronic diseases</a> resulting from workplace exposures. </p>
<p>For an advanced country, we know remarkably little about the extent and risk factors for occupational diseases. The deficiencies of the Queensland coal mine workers’ health scheme, and the lack of reliability of the findings coming from it, have again highlighted this problem.</p>
<p>Australia <a href="http://search.informit.com.au/documentSummary;dn=200801991;res=IELAPA">needs more robust surveillance</a> and other information systems to better document occupational disease, to assist in guiding prevention programs and to monitor the effectiveness of such programs. The workers of Australia deserve nothing less.</p><img src="https://counter.theconversation.com/content/57817/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Malcolm Sim led the review funded by the Queensland Department of Natural Resources and Mines. </span></em></p>Recent cases of black lung in Queensland coal miners after many years of no known cases have raised important questions about control of dust exposure in coal mines.Malcolm Sim, Professor, Epidemiology & Preventative Medicine, Monash UniversityLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/577182016-04-20T20:10:19Z2016-04-20T20:10:19ZBlack lung’s back? How we became complacent with coal miners’ pneumoconiosis<figure><img src="https://images.theconversation.com/files/119385/original/image-20160420-25631-x3niy5.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Black lung used to be commonplace among coal miners, and is now on the rise again. </span> <span class="attribution"><span class="source">from www.shutterstock.com.au</span></span></figcaption></figure><p>The name black lung says it all. When miners inhale excessive amounts of coal dust, the fine air filtration system of the lungs sieves out the dust, which then remains permanently in the lung. These deposits can even be seen with the naked eye if the lungs are removed from the body, hence the name. </p>
<p>The sinister part is the slow progressing breathing disorder that develops over many years due to excessive lung inflammation and scarring that is triggered by coal mine dust. This disease, coal workers’ pneumoconiosis or black lung, is preventable and was widely considered a thing of the past in Australian miners.</p>
<p>But just before Christmas 2015, people were shocked to hear about newly confirmed cases of black lung in Queensland miners. Governments responded swiftly to investigate the problem, with inquiries established by the Queensland government and the federal senate. </p>
<p>The Department of Natural Resources and Mines has <a href="https://www.dnrm.qld.gov.au/__data/assets/pdf_file/0008/352286/qcwp-interim-findings.pdf">released some interim findings</a> outlining poor documentation of confirmed cases, a lack of preventive measures taken where confirmed cases were found and too few screening tests being performed.</p>
<p>There is no cure for black lung. The review has recommended a greater focus on prevention and early detection, and ongoing surveillance.</p>
<h2>Preventing black lung</h2>
<p>Prevention involves managing exposure by monitoring dust levels and actively taking steps to reduce coal dust exposure in miners. Mining practices have progressively improved over the years, but overseas experience tells us not applying standards can result in cases of black lung. </p>
<p>There are no uniform standards for acceptable levels of dust exposure throughout Australia. Authorities permit Queensland miners to be exposed to coal dust levels higher than those in the United States, where the exposure limit is set at two micrograms per cubic metre.</p>
<p>Prevention also involves regular screening of exposed workers and having the results looked at by experts. The screening procedure requires imaging the lung with X-rays and assessing for possible lung impairment with breathing tests and focused clinical assessment. Each of these steps has to be quality controlled in order to successfully detect the subtle changes of black lung as early as possible.</p>
<p>The very early changes of black lung are an increase in dots and lines on the X-ray. The problem is the blood vessels and airways in the normal lung also show up as dots and lines, and so it takes expert training to tell when things become abnormal.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/119388/original/image-20160420-25595-zv5y1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/119388/original/image-20160420-25595-zv5y1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/119388/original/image-20160420-25595-zv5y1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/119388/original/image-20160420-25595-zv5y1i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/119388/original/image-20160420-25595-zv5y1i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/119388/original/image-20160420-25595-zv5y1i.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/119388/original/image-20160420-25595-zv5y1i.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/119388/original/image-20160420-25595-zv5y1i.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Black lung is difficult for doctors without specialist training to detect.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<p>Fortunately, there are ongoing improvements in imaging technology, and there are now suggestions that a low-dose CT scan may make early detection easier and more reliable. Measuring impairment of lung capacity is very accurate when done in a quality controlled lung function laboratory, and this is the standard needed when trying to detect the changes of black lung as early as possible.</p>
<p>Of course, these assessments are useless if they’re not acted on. This means it is not only important to assess the results of individual workers, but to take a helicopter view of larger numbers of workers. </p>
<p>Given the significance of the issue and the potential implications, the peak professional body, the <a href="http://www.abc.net.au/am/content/2016/s4434387.htm">Thoracic Society of Australia and New Zealand</a> believes this is best done at a national level, and independent of mining companies. There is also value in making the results of monitoring and screening accessible, so that the process is transparent.</p>
<h2>Why has black lung returned?</h2>
<p>Efforts in the 20th century to eradicate the disease including setting occupational exposure limits, introducing personal protective equipment, and improvements in dust management and health monitoring dramatically reduced the numbers of miners with black lung. </p>
<p>But in 2013, there were <a href="http://www.thelancet.com/journals/lancet/article/PIIS0140-6736(14)61682-2/abstract">25,000 deaths globally</a> recorded from black lung. State-run mines in China now <a href="http://www.atsjournals.org/doi/abs/10.1164/rccm.201511-2154ED?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed#.VxBBRkbIY4I">report</a> black lung in between 4% and 17% of workers, and in Colombia, an growing coal producer, 36% of miners were <a href="http://www.atsjournals.org/doi/abs/10.1164/rccm.201511-2154ED?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed#.VxBBRkbIY4I">recently found</a> to have black lung.</p>
<p>Black lung has been classified by <a href="http://www.safeworkaustralia.gov.au/sites/SWA/about/Publications/Documents/931/deemed-diseases.pdf">Safe Work Australia</a> as a deemed disease. This means the disease is caused by specific work-related activities, in this case prolonged exposure to coal dust. We don’t know exactly what has happened to cause black lung to reappear, but statements in the <a href="https://www.dnrm.qld.gov.au/__data/assets/pdf_file/0008/311498/qld-mines-inspectorate-annual-performance-report-2014-15.pdf">Queensland mines inspectorate report</a> of 2014-15 indicating significant dust exposure above recommended limits are highly concerning.</p>
<p>There are now even recorded increases of black lung in the <a href="http://www.atsjournals.org/doi/abs/10.1164/rccm.201511-2154ED?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed#.VxBBRkbIY4I">United States</a>. It appears that just as the coal economy is a multinational activity, so are its risks. Black lung is just one of many diseases that can develop in miners. Conditions such as silicosis, occupational COPD (colloquially called emphysema), bronchitis and occupational lung cancer all require evaluation.</p><img src="https://counter.theconversation.com/content/57718/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>Peter Gibson is affiliated with the Thoracic Society of Australia and new Zealand. </span></em></p>A review into black lung has found proper preventive measures haven’t taken place where confirmed cases have been found.Peter Gibson, Conjoint Professor, School of Medicine and Public Health, University of NewcastleLicensed as Creative Commons – attribution, no derivatives.tag:theconversation.com,2011:article/516492015-12-02T23:10:04Z2015-12-02T23:10:04ZExplainer: what is black lung and why do miners get it?<figure><img src="https://images.theconversation.com/files/104008/original/image-20151202-14458-q60qna.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=496&fit=clip" /><figcaption><span class="caption">Black lung is preventable – and hasn't been seen in Australia in more than 20 years.</span> <span class="attribution"><a class="source" href="https://www.flickr.com/photos/un_photo/7119599641/">United Nations Photo/Flickr</a>, <a class="license" href="http://creativecommons.org/licenses/by-sa/4.0/">CC BY-SA</a></span></figcaption></figure><p>Coal miners in Queensland have been <a href="http://www.abc.net.au/news/2015-12-01/'black-lung'-makes-comeback-in-queensland-coal-mines/6990842">diagnosed</a> with “black lung”, a disease that was thought to have been eradicated in Australia <a href="http://www.coalservices.com.au/MessageForceWebsite/Sites/320/Files/20120822_Press_Release_Black_Lung.pdf">more than 20 years ago</a>. Mining companies are <a href="http://www.smh.com.au/business/workplace-relations/black-lung-disease-returns-to-queensland-mines-20151201-glcqzo.html">copping heat</a> for allowing health standards to deteriorate enough to see the disease return. So what is black lung? And why is it back?</p>
<p>Black lung is a chronic, irreversible occupational lung disease caused by the inhalation and deposition of coal dust in the lungs. It is part of a spectrum of respiratory diseases caused by coal dust and is known more formally as coal workers’ pneumoconiosis.</p>
<p>With prolonged exposure, the inhaled fine dust particles overwhelm the lung’s defence mechanisms. The particles accumulate in the parts of the lung where oxygen from the air is taken up by the blood and carbon dioxide waste is released from the blood into the air (known as the “gas exchange region”). </p>
<p>This causes inflammation and scarring of the lung tissue. In the early stages of the disease these accumulations of coal dust and the affected lung tissue will show up as small (less than 1cm) rounded opacities (opaque masses) on x-rays. </p>
<p>Patients with coal workers’ pneumoconiosis may experience symptoms of shortness of breath and a chronic cough. With further exposure and time the disease may progress to a more severe form known as progressive massive fibrosis. </p>
<p>This occurs when the accumulations of coal dust and abnormal lung tissue lump together in larger lesions that show up as large (more than 1cm) opacities on x-ray. As these lesions lump together there is generally significant destruction of lung tissue, with debilitating severe symptoms including:</p>
<p>• shortness of breath</p>
<p>• chronic cough</p>
<p>• coughing up black mucus</p>
<p>• high blood pressure</p>
<p>• heart problems</p>
<p>• increased susceptibility to autoimmune conditions such as rheumatoid arthritis and scleroderma (excessive hardening of the skin).</p>
<p>Progressive massive fibrosis leads to premature death, with the outlook worsening with increasing severity of the disease.</p>
<h2>What causes black lung?</h2>
<p>The only cause of black lung is excessive inhalation of “respirable” coal dust – that is, particles that are small enough to reach the spaces in the lung where gas exchange takes place – and deposition of dust in the lungs, which causes scarring of lung tissue. </p>
<p>The occurrence and severity of the disease depends on the intensity and duration of exposure, and also to some extent on the type of coal being mined. Smoking does not increase the risk of developing this disease, but it may have an additional harmful effect on the lungs. </p>
<p>Unfortunately, once the disease process has begun it may not resolve with removal from exposure to coal dust and can progress from simple coal workers’ pneumoconiosis to progressive massive fibrosis with time.</p>
<h2>How is it treated?</h2>
<p>There is no specific treatment for either simple coal worker’s pneumoconiosis or progressive massive fibrosis that can slow or reverse the progressive scarring of the lung tissue. </p>
<p>Medical care of patients is palliative and is directed at limiting complications, such as airflow obstruction and associated lung disorders, and protecting against infectious complications. </p>
<h2>How do you prevent it?</h2>
<p>As black lung cannot be cured, the only way to control it is through preventing exposure to coal dust. The strict application of engineering controls such as dust suppression combined with ventilation systems in all mining operations is necessary to limit exposure to respirable coal dust to levels below recognised occupational exposure standards. </p>
<p>The American Conference of Governmental Industrial Hygienists has recommended <a href="https://www2.worksafebc.com/PDFs/regulation/ExposureLimits.pdf">threshold limit values</a> of 0.4 mg/m³ for anthracite (a type of coal with the highest carbon content) and 0.9 mg/m³ for bituminous coal (soft coal containing bitumen) or lignite (brown coal).</p>
<p>Due to the extremely small size of the coal dust particles that cause this disease, overexposure will not be immediately obvious to mine workers. So it is also important to regularly monitor the actual level of worker exposures, using personal respirable dust monitoring equipment, so interventions can be made if excessive dust levels are detected. </p>
<p>Medical surveillance programs are also vital, aimed primarily at early detection so interventions can be made to prevent disease progression by limiting further exposure.</p>
<figure class="align-center zoomable">
<a href="https://images.theconversation.com/files/104017/original/image-20151202-14444-760y49.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=1000&fit=clip"><img alt="" src="https://images.theconversation.com/files/104017/original/image-20151202-14444-760y49.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&fit=clip" srcset="https://images.theconversation.com/files/104017/original/image-20151202-14444-760y49.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=600&h=400&fit=crop&dpr=1 600w, https://images.theconversation.com/files/104017/original/image-20151202-14444-760y49.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=600&h=400&fit=crop&dpr=2 1200w, https://images.theconversation.com/files/104017/original/image-20151202-14444-760y49.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=600&h=400&fit=crop&dpr=3 1800w, https://images.theconversation.com/files/104017/original/image-20151202-14444-760y49.jpg?ixlib=rb-1.1.0&q=45&auto=format&w=754&h=503&fit=crop&dpr=1 754w, https://images.theconversation.com/files/104017/original/image-20151202-14444-760y49.jpg?ixlib=rb-1.1.0&q=30&auto=format&w=754&h=503&fit=crop&dpr=2 1508w, https://images.theconversation.com/files/104017/original/image-20151202-14444-760y49.jpg?ixlib=rb-1.1.0&q=15&auto=format&w=754&h=503&fit=crop&dpr=3 2262w" sizes="(min-width: 1466px) 754px, (max-width: 599px) 100vw, (min-width: 600px) 600px, 237px"></a>
<figcaption>
<span class="caption">Dust suppression and proper ventilation of coal mines can prevent the disease.</span>
<span class="attribution"><span class="source">from www.shutterstock.com</span></span>
</figcaption>
</figure>
<h2>Why has it come back?</h2>
<p>With the introduction of stringent dust control measures in mining in the developed world in the 1970s, this disease was virtually eradicated. The National Institute for Occupational Safety and Health has <a href="http://big.assets.huffingtonpost.com/NIOSHletter.pdf">monitored trends in black lung</a> for over 40 years in the United States. Only 0.08% of all mine workers and 0.33% of underground coal miners with at least 25 years of mining were diagnosed with progressive massive fibrosis in 2000.</p>
<p>However, prevalence has dramatically <a href="http://big.assets.huffingtonpost.com/NIOSHletter.pdf">increased over the past ten years</a> to 3.23% (five-year moving average) of working miners in the central Appalachian states of Kentucky, Virginia and West Virginia. Such an increase can only be the result of overexposure to coal dust. This is probably due to a relaxation of dust control regimes in many countries in recent years.</p>
<p>The Queensland Resource Council <a href="http://www.abc.net.au/news/2015-12-01/'black-lung'-makes-comeback-in-queensland-coal-mines/6990842">has admitted</a> it had become complacent with regulations because no new cases had been reported in Australia for decades. A <a href="http://www.abc.net.au/news/2015-12-01/'black-lung'-makes-comeback-in-queensland-coal-mines/6990842">review</a> will now be undertaken to assess practices that allowed this to occur.</p><img src="https://counter.theconversation.com/content/51649/count.gif" alt="The Conversation" width="1" height="1" />
<p class="fine-print"><em><span>David McLean receives funding from the New Zealand Health Research Council</span></em></p>Coal miners in Queensland have been diagnosed with “black lung”, a disease that was thought to have been eradicated in Australia over 20 years ago. So what is black lung, and why is it back?David McLean, Senior Research Officer, Centre for Public Health Research, Massey UniversityLicensed as Creative Commons – attribution, no derivatives.