Aggregates Manager Digital Magazine
Issue link: http://read.dmtmag.com/i/562664
37 AGGREGATES MANAGER September 2015 TECHNOLOGY the method used for a compliance-type dust sample. A 3-foot length of con- ductive tubing was used to connect the 10-mm cyclone to the main body of the pDR-1500 monitor. The instrument was configured to integrate samples over a 2-second period for this testing. The last item necessary for the Helmet-CAM system was a method to house the video camera, as well as the noise and dust instruments, in a way that would allow the miner to perform his or her work in an un-impeded fashion and with minimal interference. For this testing, the best approach was to provide a lightweight backpack with a number of pockets to house the camera's logger unit and the noise and dust monitor (this approach emerged as the method preferred by miners in all of NIOSH's previous testing). An ad- vantage of using the backpack is that it has two shoulder harnesses, as well as two other straps — one at chest level and the second at the waist — which allows the backpack to be securely adjusted and tightened to the wearer's needs. The other benefit with the two shoulder harnesses is that the micro- phone for the dosimeter was attached to one shoulder harness, and the 10- mm Dorr-Oliver respirable dust classi- fier was attached to the other (Figure 2). Duct tape was then used to secure all the cables in order to provide a sig- nificant level of safety to the worker to minimize the possibility of them being caught or tangled on anything while performing their work. The video camera lens was attached to the worker's hardhat using a holder for a small flashlight clip. The video unit was turned on, and the lens was adjusted to ensure that it was recording in a hori- zontally aligned manner. The aligned camera lens was also duct-taped in place to ensure that it did not move over time and lose its alignment as workers performed their job tasks. At this point, the video camera, dosimeter, and dust monitors were all started simultaneously. It was critical that all three units were started at the same time, because there is no current adjustment in the EVADE software to offset the start time. The miners were asked to return to work and to wear the Helmet-CAM system for a pre-determined time frame (Figure 3). The miners were instructed to perform their routine duties and tasks without any changes or devia- tions in relation to their wearing of the device. For all testing, the video sound function was deactivated because it was not needed. After approximately two hours, the miners returned to the mine's con- ference room, and the video camera footage was downloaded to a laptop computer. Because numerous workers were to be evaluated at the same site, it was important to differentiate the numerous videos, dosimeter data, and dust data files taken at this operation. All files were provided a name as- signed by Vulcan that could be used to distinguish between the different min- ers. When using the EVADE software, this same naming system was used to ensure that the correct video files, dust data files, and dosimeter data files were linked together in the analysis software program. Next steps With the Helmet-CAM technology being successfully used in the United States and internationally to identify and con- trol respirable silica dust exposures, the intent is to now expand this technology so that it can assess any type of physi- cal, chemical, or biological agent where an instantaneous monitoring device is used — such as monitoring of diesel particulate matter, chemical, and noise exposure levels. In a recent cooperative study be- tween Vulcan Materials Co. and NIOSH, the Helmet-CAM technology was shown to successfully be able to simultane- ously monitor and provide assessment for both noise and respirable dust ex- posures to miners. Further, the EVADE software that complements the Helmet- CAM technology is currently being ex- panded (version 2.0) to allow multiple video files and contaminant data to be viewed simultaneously. The software for assessing worker's respirable dust exposure to respirable dust (EVADE version 1.0) for the Helmet- CAM technology is currently available at the NIOSH Mining website at www. cdc.gov/niosh/mining/Works/cover- sheet1867.html. Within the next few months EVADE version 2.O will also be available at this website. AM Andrew Cecala, lead mining engineer, and Amanda Azman, research audiologist, are both researchers with the NIOSH Office of Mine Safety and Health Research in Pittsburgh, Pa. Kelly Bailey is the corporate director of safety, health, and environ- mental services for Vulcan Materials Co. Disclaimer Mention of any company or product does not constitute endorsement by the Na- tional Institute for Occupational Safety and Health. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the National Institute for Occupational Safety and Health.