Black lung is back: why more is needed to fight dust

US mining has enjoyed years of continued improvements with regard to safe operations, with falling fatalities highlighting an industry that is more aware than ever of the risks faced by its employees. Figures from the Mine Safety and Health Administration (MSHA) show that fatalities at US mining operations have fallen slightly in recent years, from 28 in 2017 to 27 in 2019, and significantly since the turn of the millennium, with the 85 deaths reported in 2000 close to triple the 2019 figure.

Yet while the industry does its best to clamp down on the hazardous practices it can control, such as implementing a culture of safety above all else and investing in adequate safety equipment, there is an inherent risk faced by miners in this sector: that of dust inhalation. Mining, by design, kicks up vast quantities of dust, and the enclosed subterranean spaces where many miners work are difficult to adequately ventilate, resulting in a significant threat to miners’ respiratory health.

Most worryingly, this trend is not improving, with reports from the US National Institute for Occupational Safety and Health (NIOSH), a part of the country’s Center for Disease Control and Prevention (CDC), noting that the prevalence of conditions such as coalworkers’ pneumoconiosis, known colloquially as ‘black lung’, is, in fact, increasing amongst US miners, raising questions about the industry’s response to the threat.

Significant risks and uneven progress

The production of dust poses significant risks for mineworkers, with both long-term health conditions arising from dust inhalation, and short-term risks of ignition and explosion, threatening miners.

“Miners exposed to quartz in respirable dust can develop lung diseases such as chronic obstructive pulmonary disease and various forms of pneumoconiosis, such as silicosis, coal workers’ pneumoconiosis, progressive massive fibrosis, and rapidly progressive pneumoconiosis,” said an MSHA spokesperson. “These lung diseases are irreversible, life limiting, and may lead to death.”

The MSHA has been proactive in tackling this threat, by working to reduce the amount of dust produced at US mines. “MSHA’s Respirable Dust Rule, fully implemented in 2016, has had the effect of controlling quartz in large measure,” said an MSHA spokesperson. “The average quartz concentration for designated occupations in underground coal mines, those miners with the highest exposure to respirable dust, has declined dramatically.

“In 2019, MSHA reported an average concentration of 24.6mg/m³, the lowest in the history of sampling and well below OSHA’s standard of 50mg/m³.”

Despite these reductions in dust concentration, even small quantities of dust can pose a significant threat to human health. These dangers are highlighted in a CDC report, ‘Coal Mine Dust Exposures and Associated Health Outcomes’, which analysed trends in dust inhalation data and related illnesses since 1995. The report noted that a mean dust concentration in a mineshaft of 8mg/m³ would yield a probability of 0.2 that a healthy miner would contract pneumoconiosis; doubling this concentration to 16mg/m³ would see this probability almost quadruple to 0.7.

In a similar vein, the report highlighted studies completed on British mineworkers in the 1980s that showed that a mean dust concentration of just 6mg/m³ could see the prevalence of progressive massive fibrosis among mineworkers reach 7%.

These threats have led to a noticeable increase in coalworkers’ pneumoconiosis, with a report from the University of Illinois at Chicago finding that there were 49 cases of the condition reported in 2016, compared to 31 across the entirety of the 1990s . The report also noted that the threats remained regardless of the mineral being mined, with coal, silica and quartz dust all contributing to the downturn in safety performance.

Industry initiatives

The MSHA is acutely aware of these threats and has led the US mining industry with a strong commitment to safety initiatives and the release of information. In 2018, the group published a request for information on the impacts of the 2016 Dust Rule on dust levels at US mines, to help guide future policy decisions regarding dust inhalation protocol, and in 2019 published a similar request for information, looking for input from industry bodies and labour organisations on how quartz dust in particular can be better managed across US mines.

The association has also announced plans to work more closely with NIOSH to further its advances in occupational safety, with a spokesperson noting that the initiative is “designed to identify ways to better protect coal miners from dust, with emphasis on quartz exposure and potential new technologies.

“MSHA is assisting NIOSH’s efforts to develop a monitor for capturing end-of-shift quartz exposure data, with the ultimate goal of developing a device capable of measuring real-time quartz exposures on the spot. MSHA also is currently developing a health effects and risk assessment of quartz for the metal and non-metal mining industry.”

In this manner, the MSHA aims to provide both practical policy and a source of leadership for a sector that has made considerable strides with regard to its safety record, but one that continues to face new challenges. With the spread of Covid-19 and the importance of self-isolation seemingly incompatible with mine work, which typically sees many miners sharing cramped workspaces, the MSHA hopes to establish itself as a proactive body on the front foot when it comes to spearheading new safety initiatives.

“MSHA will continue to work hand-in-hand with stakeholders and other government agencies to pursue and enforce standards that lead to a safer, more healthful work environment for the miners we serve.”