One of the most important health risks encountered by construction workers is exposure to respirable crystalline silica dust. Crystalline silica, mainly in the form of quartz, is the main component of most rocks, sands and clays. In the construction industry it can be found in stone, concrete, aggregates, mortars and other materials.
Respirable particles (smaller than 10 microns in diameter) of crystalline silica, which are produced during many common activities such as cutting, blasting or drilling granite, sandstone, slate, brick or concrete, penetrate deep down into the lungs where they can cause serious damage. Regular, repeated exposure to respirable crystalline silica can lead to silicosis, a debilitating lung disease, chronic obstructive pulmonary disorders (COPD) and lung cancer. It usually takes many years of exposure to silica dust before these symptoms start.
A couple of weeks ago I was giving a talk to a meeting of safety consultants on the BOHS breathefreely initative and decided to include some discussion on silica exposures in the industry. Unfortunatly no major study has been carried out in the UK. However, there are several detailed papers on exposures in the industry in some comparable countries in the Annals of Occupational Hygiene and other journals, so I was able to include some figures in my talk.
The research has shown that many of the common activities undertaken in the construction industy lead to exposures well in excess of the UK Workplace Exposure Linit of 0.1 mg/m3 for respirable silica – and this isn’t a “safe limit” with an estimated 2.5% of workers exposed to this concentration for only 15 years developing silicosis. Yet for most of the common operations where workers are at risk from exposure to silica, there are control measures available that are usually relatively straight forward to implement.
Recognition, Evaluation, Control 