Abstract
Ultrafine particles (diameter <100 nm) are of great topical interest because of concerns over possible enhanced toxicity relative to larger particles of the same composition. While combustion processes, and especially road traffic exhaust are a known major source of ultrafine particle emissions, relatively little is known of the magnitude of emissions from non-traffic sources. One such source is the incineration of municipal waste, and this article reviews studies carried out on the emissions from modern municipal waste incinerators. The effects of engineering controls upon particle emissions are considered, as well as the very limited information on the effects of changing waste composition. The results of measurements of incinerator flue gas, and of atmospheric sampling at ground level in the vicinity of incinerators, show that typical ultrafine particle concentrations in flue gas are broadly similar to those in urban air and that consequently, after the dispersion process dilutes incinerator exhaust with ambient air, ultrafine particle concentrations are typically indistinguishable from those that would occur in the absence of the incinerator. In some cases the ultrafine particle concentration in the flue gas may be below that in the local ambient air. This appears to be a consequence of the removal of semi-volatile vapours in the secondary combustion zone and abatement plant, and the high efficiency of fabric filters for ultrafine particle collection. (C) 2016 Elsevier Ltd. All rights reserved.