What's the Risk?

A worker’s chance of becoming ill from exposure to silica dust depends on the tasks performed, the amount of dust they are exposed to, and the frequency of the exposures. Each exposure to silica adds to the total load of silica in the lungs – in other words, each exposure adds to the lung damage.   

Health professionals express the total silica dose one person accumulates over time as “mg/m3 years,” usually calculated as an average exposure each year in mg/m3 multiplied by the number of years with that exposure, or by an estimated average for each year. As the total dose increases, so does the likelihood – or the risk – for developing silicosis, lung cancer, or chronic obstructive pulmonary disease (COPD).

Some workers become ill after many years of low exposure levels, while other workers who perform less frequent but high exposure tasks can become ill with a lower cumulative exposure. Why? Because a high exposure to silica dust overwhelms the lungs’ defenses, allowing most of the dust to settle deep into the lungs where it does the most damage.  It is important to remember that repeated exposures to silica add up to a total dose that can cause serious lung disease.

To learn more about the risk…

More in this section…