Haul Road Dust Control is a very important element to the efficient operation of a mining operation. Not just with regards to security but also to the workers health. Surface mining operations employ large off-road haul trucks extensively to transport material at mining properties. Historical investigation, using the United States Environmental Protection Agency’s (EPA) emissions factors for unpaved haul roads, has shown that haul trucks create the bulk of dust emissions from surface mining sites, accounting for in the region of 78%-97% of all dust emissions. This is still greater with low quality haul road dust control programs.
Observations of dust emissions from haul trucks confirm that if the dust emissions are unrestrained, they can be a safety risk by impairing the operator’s visibility. This increases the chance for haul truck accidents. Yet, the greatest long-term health hazard of dust created from hauling operations is due to inhalation of the respirable dust [median diameter <4 micrometers (?m)] along with thoracic dust, which is equivalent to the EPA’s characterization of PM10 [particulate matter with a median diameter <10 ?m]. Exposure to respirable dust has long been considered a health risk at surface mining operations, particularly if silica dust is there.
Present are two governmental acts that regulate the air quality for mining operations: the Federal Coal Mine Health and Safety Act of 1969 and the Clean Air Act of 1970. The Federal Coal Mine Health and Safety Act of 1969 established the limits designed for dust in the work place for healthiness and security purposes. The Clean Air Act of 1970 controls air emissions from facilities from an environmental perspective. Characterizing fugitive dust emissions from haul trucks may help mine operators comprehend the effects of exposure.
The Federal Coal Mine Health and Safety Act of 1969 established a threshold for coal respirable dust of 2 mg/m3 for coal pit staff. The U.S. Mine Safety and Health Administration (MSHA) enacts and enforces quarry employee safety and health values to diminish mine worker injuries along with occupational diseases. If silica is encountered in the course of the sampling procedure then the applicable respirable dust standard is reduced to the amount of 10 divided by the percentage of quartz appearing in the dust. Representing non-coal mine staff, the applicable standard is the respirable dust standard of 10 divided by the sum of the quartz percentage added to 2. Both of these dust standards are intended to limit employee respirable crystalline silica (quartz) exposure to 0.1 mg/m3 or fewer for the work shift. Falling in line with these dust standards is projected to decrease a worker’s chance of job-related lung disease over an average life expectancy. Moreover, MSHA’s nuisance dust maximum value (total dust) for non-coal miners is 10 mg/m3.