Correlation of respirable dust concentrations with total dust concentrations at workplaces

Objective To understand the correlation of respirable dust concentrations with total dust concentrations at workplaces and to provide the effective control measures against dust hazards. Methods The total dust and respirable dust at workplaces in 9 plants were measured according to national guideline. Results Totally 58 paired samples were collected. The standard-exceeding rates with national occupational exposure limits were 77.5% (total dust) and 68.9% (respirable dust) respectively and the difference had no significance (χ²=3.155,P>0.05). The ratio(total dust/respirable dust)varied among 1.15-21.58. The linear correlation between total dust and respirable dust in a sporting goods factory was found (24 samples) and the respirable dust can be estimated with formula Y=0.175 X + 0.654 (r=0.816,P<0.05). Conclusion The dust hazards in the enterprises should not be overlooked. The correlation of respirable dust concentrations with total dust concentration at workplaces was not constant in all plants and it should be carefully used to predict the respirable dust concentration based on the total dust concentration.