[Risk assessment of occupational health effect of coal dust in coal wharf]

To assess the occupational health risk of coal dust in coal wharf, identify the high risk post.

The research took workers who were exposed to coal dust in two 50- 150 thousands tons coal wharfs around bohai as subjects. The field investigation to get the infoamtion of production technology, distribution of coal dust, free silica content of coal dust, dust prevention measures and facilities, personal protection equipment, occupational health management, etc were used. The coal dust concentration of workplaces and the main positions were detected by filter membrane weighing method. The health risk of the coal dust to the main posts were assessed with the InternationalCouncil on Mining and Metals risk assessment method and occupational hazard risk index method.

In the coal wharf, the concentration of coal dust at transferring tower, car dumper, ship loader, and coal storage yard were higher than other workplace, range of concentration: total dust 8. 8-85. 1 mg/m~3, respirable dust 2. 3- 32. 3 mg/m~3。The assessing result of ICMM method was that, 78. 6% of the posts were at "intolerable"level of occupational risk. The risk values of the driver of car dumper( 1500, 5000), the hatch commander( 1500), and the cleaners of coal storage yard( 900) were higher than transfer tower patrol workers( 600), drivers of material piling and taking machine( 450). The assessing result of occupational hazard risk index method was that, the risk degree of total dustand respirable dusttothe driver of car dumper was "severe"and "moderate"( the risk index was 40. 03 and 16. 95, respectively), and the risk degree of the total dust to the cleaners of coal unloading department and coal storage yard were "light"( the risk index was 6. 02 and 8. 70, respectively), with other posts' "no harm ".

The occupational hazard of coal wharf is focused on the processes of loading and unloading( "severe"and"moderate"), transferring( "light") and reentrainment( "light").