105 Characterisation of aerosol emissions and short-term exposure from line marking sprays in free state underground gold mines

Abstract Marking off the face and support lines using aerosol spray paint is an integral part in gold mines before any drilling takes place. While the task is brief, the activity takes places in stopes and development ends which are confined. Aerosol spray paints contain volatile organic compounds (VOCs) which generate inhalable and respirable particulate matter and solvent vapours. The emissions from this short-term exposure can contribute to both acute neurological and respiratory health effects. Despite the prevalence of this activity in underground mining, exposure characterisation is limited and monitoring is mainly on an 8-hour TWA instead of the Short-Term exposure. A mixed method sampling programme using passive sampling and gravimetric sampling was undertaken multiple working places including stoping and development ends. The sampling was focused on both stopers and developers as they are primarily responsible for marking off activities. The paper will conclude by compare exposures based on different parameters of working places such as face length, stoping width, ventilation and size of development end. Control strategies will be further evaluated which are aligned to hierarchy of controls. Preliminary results shows that aerosol spray paints used in marking off the face and support lines in underground gold mines present a unique exposure profile. Results show that exposures can exceed short-term occupational exposure limits despite the 8-hour TWA shows low readings.