About airborne exposure
The airborne exposure assessment of workplace hazards in both the open pit and underground mines have showed that the principal air pollutants in the breathing zone of miners are aerosols with low content of silicon dioxide, nitrogen oxides, carbon monoxide, trinitrotoluene frequently exceeding the occupational exposure limits.
One of the health risks from working in mining industry is that of exposure to fine dust containing crystalline silica (otherwise known as quartz). Quartz is found in almost all kinds of rock, sands, clays, shale and gravel. Workers exposed to fine dust containing quartz are at risk of developing a chronic and possibly severely disabling lung disease known as "silicosis". It usually takes a number of years of regular daily exposure before there is a risk of developing silicosis. Silicosis is a disease that has only been seen in workers from industries where there is a significant exposure to silica dust.
In addition to silicosis, there is now evidence that heavy and prolonged workplace exposure to dust containing crystalline silica can lead to an increased risk of lung cancer. The evidence suggests that an increased risk of lung cancer is likely to occur only in those workers who have developed silicosis.
It should also be noted that excessive long term exposures to almost any dust, are likely to lead to respiratory (breathing) problems.
Particularly important is that a significant part of aerosols are presented by particles at aerodynamic diameter below 100 nm which are mostly originated from fuel combustion processes in diesel engines widely used in mining machines. The increase in morbidity and mortality of population exposed to airborne nano-size particles has been proved to associate with cardiovascular diseases rather than with pulmonary disorders. Little is known why the cardiovascular system is apparently vulnerable to the ultrafine particle exposure.
Picture from Kirovsk open pit mine in late spring
There is a wide gap in information on the health risks to specify which levels of control are required in the presence of ultrafine particles in air and cold and thus to provide guidance on choice of proper control measures.
For further information: www.minehealth.eu