Monitoring of polycyclic aromatic hyrdrocarbon (PAH) emissions from real world uses of domestic coal braziers

Residential coal combustion for cooking and heating purposes has been identified as a major source of fine particle mass emissions, and particulate polycyclic aromatic hydrocarbons (PAHs). PAHs have potential human health implications and this has motivated studies and analyses of these compounds. This paper investigates PAH emissions from household coal fires prepared using the Basa njengo Magogo (top-lit updraft) and the traditional (bottom-lit updraft) fire lighting methods. The two different fire lighting methods were compared in imbawulas/braziers with three different ventilation rates (i.e. high, medium, and low). A novel, miniature denuder developed and tested at the University of Pretoria was used to monitor PAH emissions from the fires. The denuder consists of two silicone rubber traps in series separated by a quartz fibre filter. The denuders were positioned 1 m away from the fire and were connected to pumps that sampled 5 litres of air over a 10 min sampling interval. Monitoring of PAH compounds was limited only to the ignition phase. Changes in combustion conditions appeared to have a marked effect on the PAH emissions. Samples collected when employing the traditional fire lighting method contained higher concentrations of polycyclic aromatic hydrocarbons. The Basa njengo Magogo method in a well-ventilated imbawula proved to be more efficient with lower concentrations of PAHs detected. The PAHs which were detected were primarily naphthalene, fluorene and phenanthrene.