The Correlation Of The Determination Results Between Dust Area Sampling And Personal Sampling In Coal Mine

ObjectiveIn 1950s, occupational health standards for dust were the maximum allowable concentration (MAC) in China, and used area sampling method for the determination of total dust concentration, through which, get the environmental instantaneous concentration (EIC), which cannot reflect the total dust exposure time and quantity of the workers. In 2004 and 2007, Chinese government promulgated and implemented a new occupational exposure limits and sampling specifications. The original standard for MAC was replaced by the standard of permissible concentration-time weighted average (PC-TWA) and the excursion limits (EL). Sampling methods have also been changed from the previous short-term total dust concentration measurement into long-term personal sampling, which mainly measured the TWA concentration of respirable dust.In order to effectively use the previous dust monitoring data and to facilitate grass-roots units in an appropriate way to EIC into TWA, this survey observed the changes of EIC and TWA concentrations in coal mining dust workplaces, estimated the correlation between the two concentrations and use area sampling at a fixed location according to working tasks to estimate the rationality of TWA.MethodsThe workers in coal mining workplace were selected. After surveying the occupational sanitation, take area sampling and personal sampling to determine the dust levels in workplaces, getting EIC and TWA concentrations. And then use statistical software SPSS12.0, to analyze the EIC and TWA (correlation and linear regression analysis) to determine whether they are correlated. Meanwhile, according to the survey and EIC sampled by area sampling, estimate TWA, and analyze the relationship between estimated TWA and measured TWA (obtained by the personal sampling) by the statistical analysis (t test), judging that whether there is significant difference. By this, we can estimate the reasonableness of using area sampling method to compute TWA values, and provide the theoretical basis for EIC to be converted into TWA.Results1. Through correlation and linear regression analysis, there is a positive correlation between the EIC and TWA in coal mining dust workplaces, and the linear regression equation is as follows:Y=0.8592X+0.2624 (r=0.979, P=0.001)2. There was no significant difference between the estimated TWA values and the measured TWA values (student t tests, t=0.9830,P>0.05).ConclusionIn the Coal mining enterprises, there is linear positively relationship between the dust EIC and TWA. After detailed investigation and ensure that truly representative samples collected, we can estimate the TWA by area sampling method, and there is no difference between the TWA values.