“…Chen et al (Chen et al, 2005) studied the impact of geological maturity to the emission factors (EFs) of PAHs from coal combustion and found that the combustion of bituminous coal with vitrinite reflectance (R O , a measure of the geological maturity of coal) around 0.9% produced the highest EFs of particulate matter, elemental carbon, organic carbon, and PAHs. Shen et al (Shen et al, 2013a) studied the influence of volatile matter (VM) content on the emissions of PAHs and found that medium volatile bituminous coal emitted relatively large quantities of PAHs in comparison with low and high volatile bituminous coals. Meanwhile, the studies of Simoneit (Simoneit, 2002) and Shen et al (Shen et al, 2013a) suggested that the fast burning of low moisture biomass fuel forms an oxygen deficient atmosphere yielding high pollutant emissions, whereas the burning of high moisture fuel requires extra energy to vaporize water reducing combustion temperature and efficiency, and hence increased emissions of incomplete combustion products, such as PAHs and their derivatives.…”