Abstract
In an effort to quantify diesel particulate exposures in the mining industry, various organizations have developed diesel particulate sampling instruments. These instruments work on a variety of different principles. These principles include the use of size-selective sampling utilizing inertial impaction, the measurement of respirable combustible dust (RCD), and the measurement of elemental carbon. The RCD methods provide measurements of whole diesel particulate. The size-selective and elemental carbon methods provide a measurement of a fraction of the diesel particulate matter. The size-selective and RCD methods are limited by gravimetric analysis. The elemental carbon method is limited by filter loading. A series of tests were conducted to compare the measurements obtained with the various diesel particulate sampling instruments and analytical methods. The tests were conducted at two underground mining facilities, a zinc mine and a potash mine. Similar tests are scheduled to be conducted in coal and other dieselized metal mines. A portable test chamber containing 30 sample ports was utilized for these tests. The sample chamber inlet was equipped with two cyclones that matched the American Conference of Governmental Industrial Hygienists respirable dust criteria at air flows up to 30 L/min. The three different sampling devices were attached to the chamber in groups of ten for each test. The sample pumps utilized for the size-selective and the RCD sampling devices were calibrated and operated at 1.7 L/min. The flow rate of the sample pumps utilized with the elemental carbon filters was varied from 1.0 to 1.7 L/min depending on the test location to reduce overloading of the filter. This article provides a description of the test procedures and a preliminary summary of the results. For each type of measurement, the average for each sample type is compared and a coefficient of variation is calculated.