As a contractor that is involved in both demolition and construction, we deal with silica on a routine basis. Silica is one of the most common minerals on earth and it is found in many of the building products used on our job sites. It is found in sand and many types of rock and also in man-made products such as concrete, shingles, and some types of paint. When these materials are crushed, cut, or demolished, silica is released in a fine dust and if it is airborne, it becomes a health hazard to our employees. When the silica particles are inhaled, they become trapped in the lung and can’t be cleared out. The particles cause scarring in the lung and block the oxygen / carbon dioxide exchange that normally occurs. The resulting disease is called silicosis.
Silicosis is one of the oldest occupational diseases and it kills hundreds of people each year. It can take up to 20 years to develop depending on the exposure levels, but it can also develop in a matter of weeks if a person is exposed to high enough concentrations. Silicosis is a disease that cannot be cured, but it is 100% preventable.
The first method of prevention is always to try to eliminate or minimize the exposure through engineering controls, for example:
When chipping concrete, use water to minimize the amount of dust that becomes airborne.
If possible, use local exhaust ventilation to reduce the airborne dust where it originates.
When sweeping up sand or mortar products, keep them wet.
Some portable tools have dust collection accessories or can be connected to a water supply to minimize the exposure to silica.
When air monitoring shows that the engineering controls are not adequate, respiratory protection is the next step. Employees must be medically cleared, fit tested, and trained on how to use a respirator and on the health effects of exposure to silica. Employees should also remember to wash their hands before eating, drinking, or smoking, and should change their clothes after work to reduce the amount of dust that is brought home to their families.
As always, it is most important to recognize the hazard and plan remedies in advance. Make sure to include employee safety when planning work activities.