Evaluation of instruments for dust monitoring in United Kingdom coal mines

Abstract The United Kingdom Respirable Dust Regulations for underground coal mines are currently under review; new regulations that are under development will introduce new dust measurement methods and monitoring strategies. Research was undertaken to evaluate instruments for the monitoring of dust and quartz in United Kingdom coal mines and to determine current levels of personal dust exposure in the industry. The aim of the research was to identify instruments capable of being deployed more flexibly in a range of mine workings. The CIP10 respirable dust sampler, developed by CHERCHAR, was identified as a suitable instrument for both personal and fixed-point measurements of respirable dust and quartz. In fixed-point measurements the CIP10 results were highly correlated with colocated results obtained with the MRE 113a horizontal elutriator—the instrument stipulated in the current United Kingdom regulations. As the CIP10 is small, light and has a long battery life, it can be used for full-shift personal dust monitoring in both large and small mines. Personal respirable dust exposures measured during an underground survey that formed part of the research were lognormally distributed with a median value of 1.8 mg/m3 and a geometric standard deviation of approximately two. There was limited evidence of higher mean exposures for certain mine-workers. In general, personal exposure measurements did not differ greatly from fixed-point measurements. The introduction of personal monitoring in United Kingdom coal mines will, however, enable the most highly exposed individual mine-workers to be identified and dust control measures to be directed in a cost-effective manner. Personal monitoring was found to be particularly useful in the assessment of localized dust concentrations in smaller mines and in the development areas of larger mines, where representative fixed-point sampling can be problematic.