It is estimated that about 5 million workers in the European Union are exposed to crystalline silica dust. Mineral dusts pose the greatest risk of environmental lung diseases in mining, construction and some other industries.

Respirable crystalline silica (RCS) is classified by the IARC as a Group 1 carcinogen, which means that it is considered a definite cause of cancer in humans. RCS can cause severe respiratory diseases and even lung cancer with prolonged exposure and the risk occurs via inhalation of dust.

Where risks occur

Exposure to silica dust occurs mainly in surface and underground mining and in construction (civil and underground engineering). In the field of underground engineering, the areas of earthworks, rock construction and tunnelling are particularly worth mentioning. In addition, branches in which crystalline silica is used as a raw material include the cement industry, the chemical, ceramic and glass industry (glass melting sand), the foundry industry (foundry sand) and the rubber, plastics and paint industry (filler). Large-scale dust emissions that may contain respirable crystalline silica are also possible in agriculture or horticulture. In most cases, workers are employed in microenterprises with a maximum of nine employees.

Silica dust is mainly generated during the extraction and processing of raw materials containing silica-bearing minerals. In addition, silica dust is generated by (mainly mechanised, high-speed) processing operations such as cutting, sawing, drilling, grinding and crushing of rock, concrete, asphalt, mortar, bricks and ceramic products. Other activities include handling, mixing or shovelling dry materials containing crystalline silica, also processes such as compressed air blasting with sand or glass can lead to a release of silica dust.

Dust that has already settled can also become airborne again when stirred up by vehicles or wind, which can also expose by-standing people on the construction site.

More about the substance

Crystalline silica or silicon dioxide is the second most common mineral in the earth’s crust. It occurs in varying amounts in most rocks, and makes up the majority of the world’s sand deposits. It is also found in clay in smaller quantities. Products in which silicon dioxide is bound are not hazardous. However, during the extraction and processing, i.e. blasting, cutting, chipping, drilling, grinding etc. of products containing silica, small particles can be produced that can get into the lungs and endanger them (“respirable crystalline silica”).

How the symptoms can affect you

The main health effect resulting from the inhalation of crystalline silica dust is the development of silicosis. Silicosis is a permanent scarring of the lungs due to inhaled silica dust. Upon physical exertion, breathing difficulties that sometimes develop into shortness of breath at rest occurs. Some people also have a cough with or without expectoration. Early symptoms for silicosis can also be a tendency to develop respiratory infections. It is unclear how exactly respirable crystalline silica causes lung cancer – the most likely cause is the accumulation of dust in the lungs. Its toxicity makes it difficult for the body’s natural defence mechanisms to remove the dust, so it remains in the lung tissue and causes constant inflammation.

What you can do

The best solution is to prevent the formation of particulate matter through substitution, for example by using low-dust products (e.g. silo goods instead of bagged goods). If replacement is not possible, exposure to silica dust should be prevented or at least reduced. You can achieve dust prevention or reduction by using low-dust working methods and machines that work with extraction or wet processing. Regularly clean work areas and workrooms, avoid of dust deposits, and most important avoid to stir up dust again during cleaning (i.e. do not dry sweep or blow off, but use dust extractors or vacuum sweepers). Continuously monitor whether dust formation occurs and risk management measures need to be adapted.

In the case of dust-intensive activities, the work areas should be divided in separate areas in which the work can be carried out consecutively in order to prevent third parties from coming into contact with dust.

Personal protective equipment (respiratory protection) should only be used as a last resort when technical measures are not sufficient to protect the wearer from inhaling harmful dusts, vapours or gases. However, for some workplaces or work tasks, a respirator may be the only practical solution.