Monitoring air quality in mining: Importance and best practices

Image above provided courtesy of Envirosuite. 

TL;DR — Mining operations can contribute to air pollution at every stage of the process, and have significant impacts on the health of both those working at the sites and those living in surrounding communities. Fortunately, a number of best practices exist that can help alleviate mining’s impacts on the environment, including using dust suppression techniques, increasing vehicle efficiency, addressing occupational health and safety concerns at mining sites, promoting sustainable mining practices, and establishing real-time air quality monitoring networks at the sites — all of which aid in the work for cleaner air.

Understanding the impact of mining on air quality

Mining operations contribute significantly to poor air quality across the globe.

Every stage of the mining process, including the ore extraction, generation of solid waste, and ore refining and processing, creates air pollution that has environmental and public health impacts.”

— Earthworks

Both above-ground and underground mining processes produce air pollution and can generate harmful aerosols, including particulate matter, arsenic, and diesel.

One primary source of mining air pollution comes from mineral extraction, including the processes of excavation, blasting, transportation of materials, and wind erosion. Vehicles and heavy equipment used during mining also produce exhaust emissions that contribute to these pollution levels.

With metal mining, very high temperatures are used as part of the smelting process. Though the technology has improved significantly over the past 50 years, smelting can still contribute to a variety of toxins, including:

• Lead
• Nitrogen and sulfur
• Mercury
• Sulfur dioxide
• Zinc, cadmium, and uranium

Sulfur dioxide can lead to acid rain, which can wreak havoc on environmental health.

Smelting also releases large amounts of greenhouse gases into the atmosphere, which has severe and long-lasting impacts.

Aluminum smelters, for example, release two tons of carbon dioxide and 1.4 kilos of perfluorocarbons (PFCs) for every ton of aluminum produced. PFCs have up to 9,200 times the heat-trapping potential of carbon and will linger in the atmosphere for tens of thousands of years.”

— Earthworks

The significance of air quality monitoring in mining

Not only is air quality monitoring often required to ensure that air pollution levels from mines abide by regulatory guidelines, but it is also extremely important to understand pollution exposure levels and protect workers, surrounding community members, and the environment. 

For more information on the benefits of air quality monitoring services for industrial and mining operations, read our blog here.

The best practices for air quality control in mining

Air quality is commonly monitored around mining operations to determine the level of air pollution present at the site — this helps set a baseline for any further air quality improvement initiatives which we have included here. Read our case study with First Quantum here to learn more about their important work to improve air quality in their mining operations.

One useful practice that can be employed is dust suppression, which helps in reducing pollution levels as well as improving visibility. 

A variety of technologies and practices exist to aid in dust suppression, including surface miners, mist sprayers, and wet drilling. These systems may be installed at loading, transfer, and unloading points within the mine to address dust generation at a variety of sites. 

Wind screens can also be used to limit the movement of dust in particular areas.

Regular vehicle maintenance is highly important in addressing mining air pollution.

With coal mining specifically, dust generation and propagation are controlled at the source by a variety of technologies, including fixed sprinklers at coal handling plants and along roads used for transportation. 

Mobile water sprinklers can also be used along haul roads and other major roads used for transport to reduce dust being stirred up.

Another best practice is to cover coal-transporting trucks with tarps to prevent coal from spilling out during transit.

The air quality in these large opening nonmetal mines can be significantly improved by using diesel particulate matter (DPM) controls along with sufficient ventilation quantities to remove contaminants. Practical methods of ventilating these underground stone mines can be accomplished by using mine layouts that course and separate ventilation air through the use of stoppings”

— U.S. Centers for Disease Control and Prevention

For more information about minimizing air pollution production at industrial sites, read our blog focusing on construction and air quality here.

Another vital part of controlling air pollution at mining sites is to establish real-time air quality monitoring. Many countries have established such networks at their mining sites, helping to inform construction managers of air pollution levels at the site and notify workers should air pollution spike. 

Occupational health and safety in air quality control

There has been a widespread recognition that mining air pollution poses a significant risk to the health of mining workers, and regulations have developed accordingly.

Workplace regulations in the United States are overseen by The Occupational Safety and Health Administration (OSHA) and similarly the European Agency for Safety and Health at Work (EU-OSHA) in Europe.

On a global level, the International Labour Standards on Occupational Safety and Health (ILO) work to protect workers from sickness, disease, and injury. 

The ILO has a number of labor standards involving health and safety in mines, including the “Guide to the prevention and suppression of dust in mining, tunneling and quarrying” code of practice, which can be viewed here.

Promoting sustainable mining practices

By working to implement more sustainable mining practices that reduce air pollution generation, we can enjoy the benefits of cleaner air.

Ventilation is one key component of achieving less polluted air from mining — both because it reduces air pollution concentrations, but also because having a more effective ventilation system is more energy efficient.

Approximately 50% of energy consumed by mining operations is used by ventilation systems. An automated mine ventilation system ensures a safe and cost-efficient way of controlling the supply of fresh air underground. Optimizing the ventilation system lowers workers' exposure to noxious gases and reduces their risk of injury. Monitoring gas concentrations is also vital for workers' safety.”

— Canadian Mining Journal

Green mining practices, such as methane capturing techniques can help to keep methane gas — a byproduct of coal mining — to a minimum. For example, fans can be used to pull methane out of the mine, oxidize it, and turn it into carbon dioxide and water vapor to be released into the atmosphere. While CO₂ still poses a threat to the climate, it is less potent than methane and does not pose the same risk of triggering explosions in the mine if left unchecked.

Using more energy-efficient vehicles in mining operations also helps to make mining more environmentally friendly. Clean diesel fuel or alternative energy sources can be used, in addition to hybrid power sources such as diesel-rechargeable and hydrogen fuel cell-rechargeable batteries, to power vehicles.

Managing air pollution in mining: Environmental regulations and compliance

Air pollution from mining is generally regulated by governmental agencies that also monitor the air quality with reference to other pollution sources — such as the US EPA and UNEP.

Most countries around the world have some sort of regulation in reference to mining as well as industrial activities.

For example, mining workers in Canada must either water the area as a dust suppression technique, shut down the site, or implement an emergency response plan when air pollution levels at a site exceed the country’s guidelines for a 15-minute period.

In the United States, the mining regulations work to both govern current regulations and improve old ones.

The framework for mining regulation [in the United States] is primarily based on federal laws dating back to the late 1960s. In many cases, these regulatory responsibilities have been delegated to state agencies, which have in turn developed their own sets of environmental laws, regulations, and standards. Regulatory standards established at state levels are commonly equal to or more stringent than federal standards.”

— American Geosciences Institute

Community impact and engagement

Air pollution from mining has very real impacts on the everyday lives of those at the site as well as those living in surrounding communities.

One role model in addressing these impacts of mining air pollution is Kansanshi Mine in Zambia, a subsidiary of First Quantum Minerals, which established a real-time air quality monitoring network around their mining operations to understand true air pollution levels and address community concerns.

A future of cleaner mining

While mining activities can have significant negative impacts on air quality, many practices and technologies can be employed to mitigate these harms. This work helps to protect employees at the site and those in surrounding communities that may suffer from exposure to air pollution produced by mining.

Interested in learning more? Check out our Air Quality Monitoring for Mining & Industrial Facilities page here to learn more about enhancing industrial air quality monitoring to better understand pollution levels at your mining site and protect industry workers and surrounding communities.