Cancer and construction: Silica

What is it?

Silica is a natural substance found in varying amounts in most rocks, sand and clay. For example, sandstone contains more than 70% silica, whereas granite might contain 15-30%. Silica is also a major constituent of construction materials such as bricks, tiles, concrete and mortar.

You generate dust from these materials during many common construction tasks. These include cutting, drilling, grinding and polishing. Some of this dust is fine enough to get deep into your lungs. The fine dust is known as respirable crystalline silica (RCS) and is too fine to see with normal lighting. It is commonly called silica or silica dust.

What is the risk to construction workers?

Silica is the biggest risk to construction workers after asbestos. Heavy and prolonged exposure to RCS can cause lung cancer and other serious respiratory diseases. HSE commissioned estimates it was responsible for  the death of over 500 construction workers in 2005. In addition to the risks from lung cancer, silica is also linked to other serious lung diseases:

• Silicosis can cause severe breathing problems and increases the risk of lung infections. Silicosis usually follows exposure to RCS over many years, but extremely high exposures can cause acute silicosis more quickly.
• Chronic obstructive pulmonary disease is a group of lung diseases including bronchitis and emphysema. It results in severe breathlessness, prolonged coughing and chronic disability. It can be very disabling and is a leading cause of death. Around 4000 deaths are estimated annually due to COPD resulting from past workplace exposures in the past. Construction workers are a significant at risk group within this.