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It is a common practice in developing countries and in some regions of Europe that solid wastes generated in households (e.g. plastic beverage packaging and other plastic wastes, textile wastes, fibreboards, furniture, tyres, and coloured-paper waste) are burned in wood- or coal-fired stoves during the winter months. In Europe, the types and volume of municipal waste burned in households is virtually unknown because these activities are illegal and not recorded, with the exception of a few media reports or court cases. Even though particulate emissions from illegal waste burning pose a significant hazard to human health due to the combination of excessive emission factors (EFs) and uncontrolled chemical composition, there is scarce information on the specific EFs for PM10 and polycyclic aromatic hydrocarbons (PAHs) in the scientific literature. In this work, controlled combustion tests were performed with 12 different types of municipal solid waste, and particulate emissions were measured and collected for chemical analysis. Absolute EFs for PM10 and PAHs as well as the benzo(a)pyrene (BaP) toxicity equivalent of the latter are reported for the first time for the indoor combustion of 12 common types of municipal solid waste that are frequently burned in households worldwide. It was found that the PM10 emission factors from the combustion of wood-based waste samples were about twice that of firewood, whereas EFs in the range of 11–82 mg g−1 (a factor of 5–40 times higher than that of dry firewood under the same conditions) were obtained for different types of plastic waste. The latter were also found to emit exceptionally high quantities of PAHs, by a factor of 50–750 more than upon the combustion of dry firewood under the same conditions. Since the more toxic 4–6 ring PAHs were predominant in the particulate emission from plastic waste burning, BaP equivalent toxicity was up to 4100 times higher than that from wood combustion.

It is a common practice in the developing countries and in some regions of Europe that solid wastes generated in the households (e.g. plastic beverage packaging and other plastic wastes, textile wastes, fibreboards, furniture, tyres, and coloured paper waste) are burned in wood- or coal-fired stoves during the winter months. In Europe, the types and volume of municipal waste burned in households is virtually unknown because these activities are illegal and not recorded, with the exception of a few media reports or court cases. Even though particulate emissions from illegal waste burning pose an unprecedented hazard to human health due to the combination of excessive emission factors (EFs) and uncontrolled chemical composition, there is scarce information on the specific emission factors for PM10 and polycyclic aromatic hydrocarbons (PAHs) in the scientific literature. In this work, controlled combustion tests were performed with 12 different types of municipal solid waste and particulate emissions were measured and collected for chemical analysis. Absolute emission factors for PM10 and PAHs as well as the benzo(a)pyrene toxicity equivalent of the latter are reported for the first time for the indoor combustion of 12 common types of municipal solid waste that are frequently burned in households worldwide.

Source apportionment (SA) of carbonaceous aerosol was performed as part of the EMEP Intensive Measurement Periods (EIMPs), conducted in fall 2008 and winter/spring 2009. Levels of elemental carbon (EC), particulate organic carbon (OCp), particulate total carbon (TCp), levoglucosan and 14C in PM10, observed at nine European rural background sites, were used as input for the SA, whereas Latin Hypercube Sampling (LHS) was used to statistically treat the multitude of possible combinations resulting when ambient concentrations were combined with appropriate emission ratios. Five predefined sources/subcategories of carbonaceous aerosol were apportioned: Elemental and organic carbon from combustion of biomass (ECbb and OCbb) and from fossil fuel (ECff and OCff) sources, as well as remaining non-fossil organic carbon (OCrnf), typically dominated by natural sources. The carbonaceous aerosol concentration decreased from South to North, as did the concentration of the apportioned carbonaceous aerosol. OCrnf was more abundant in fall compared to winter/spring, reflecting the vegetative season, and made a larger contribution to TCp than anthropogenic sources (here: ECbb, OCbb, ECff and OCff) at four of the sites, whereas anthropogenic sources dominated at all but one sites in winter/spring. Levels of OCbb and ECbb were typically higher in winter/spring than in fall, due to larger residential wood burning emissions in the heating season, whereas there was no consistent seasonal pattern for fossil fuel emissions. Biomass burning (OCbb + ECbb) was the major anthropogenic source at the Central European sites in fall, whereas fossil fuel sources dominated at the southernmost and the two northernmost sites. In winter/spring, biomass burning was the major anthropogenic source at all but two sites. Addressing EC in particular, fossil fuel sources dominated at all sites in fall, whereas there was as shift towards biomass burning in winter/spring for the southernmost sites. Influence of residential wood burning emissions was substantial already in the first week of sampling in fall, constituting 30–50 % of TCp at most sites, showing that this source can be dominating even at a time of the year when the ambient temperature in Europe is still rather high. Model calculations were made, attempting to reproduce LHS-derived OCbb and ECbb, using two different residential wood burning emission inventories. Both simulations strongly under-predicted the LHS-derived values at most sites outside Scandinavia. Emissions based on a consistent bottom-up inventory for residential combustion (and including intermediate volatility compounds, IVOC) improved model results at most sites compared to the base-case emissions (based mainly on officially reported national emissions), but at the three southernmost sites the modelled OCbb and ECbb concentrations were still much lower than the LHS source apportioned results. The current study shows that natural sources is a major contributor to the carbonaceous aerosol in Europe even in fall and in winter/spring, and that residential wood burning emissions can be equally large or larger than that of fossil fuel sources, depending on season and region. Our results suggest that residential wood burning emissions are still poorly constrained for large parts of Europe. The need to improve emission inventories is obvious, with harmonization of emission factors between countries likely being the most important step to improve model calculations, not only for biomass burning emissions, but for European PM2.5 concentrations in general.

Beddows, D. C. S. ... et. al.-- 22 pages, 11 figures, 1 table, supplementary material related to this article is available online at http://www.atmos-chem-phys.net/14/4327/2014/acp-14-4327-2014-supplement.pdf, Clusteranalysis of particle number size distributions frombackground sites across Europeis presented. This generated a total of nine clusters of particle size distributions which could be further combined into two main groups, namely: a south-to-north category (four clusters) and a west-to-east category (five clusters). The first group was identified as most frequently being detected inside and around northern Germany and neighbouring countries, showing clear evidence of local afternoon nucleation and growth events that could be linked to movement of air masses from south to north arriving ultimately at the Arctic contributing to Arctic haze.The second group of particle size spectra proved to have narrower size distributions and collectively showed a dependence of modal diameter upon the longitude of the site (west to east) at which they were most frequently detected.These clusters indicated regional nucleation (at the coastal sites) growing to larger modes further inland. The apparent growth rate of the modal diameter was around 0.6-0.9 nm h-1. Four specific air mass back-trajectories were successively taken as case studies to examine in real time the evolution of aerosol size distributions across Europe. While aerosol growth processes can be observed as aerosol traverses Europe, the processes are often obscured by the addition of aerosol by emissions en route. This study revealed that some of the 24 stations exhibit more complex behaviour than others, especially when impacted by local sources or a variety of different air masses. Overall, the aerosol size distribution clustering analysis greatly simplifies the complex data set and allows a description of aerosol aging processes, which reflects the longer-term average development of particle number size distributions as air masses advect across Europe. © 2014 Author(s), The National Centre for Atmospheric Science is funded by the UK Natural Environment Research Council. This work was also supported by the European Union EUCAARI (Contract Ref. 036833) and EUSAAR (Contract Ref. 026140) research projects

A simple approach is suggested here to give reliable estimates on the Raoult term of the Köhler equation when calculating critical supersaturation (Sc) for real atmospheric samples. Water activity is calculated from osmolality and thus the original Köhler equation can be applied avoiding the difficulties with unknown molecular weights, solubilities, van't Hoff factors of aerosol constituents and also the interactions in the growing droplet. First, water activity calculated from osmolality data was compared to literature values both for electrolytes and a non-electrolyte. Then the applicability of the approach was demonstrated by generating Köhler curves from osmolality derived and literature activity data as well as by using the simplified Köhler equation. Sc values calculated with the osmolality approach fitted those obtained by using literature water activity data within a relative deviation of less than 0.3%, 0.8%, 1.1% and 3.4% for sucrose, CaCl2, NaCl and H2SO4, respectively, while the corresponding errors with the simplified Köhler equation were 11%, 8.5%, 4.5% and 19% in the dry nucleus size range of 20 nm to 100 nm. Finally, the osmolality method was used to show how considerably Sc is underestimated for organic acids if complete dissociation is assumed. The method described in this paper can be applied to real atmospheric samples (aerosol extracts, fog water or cloud water) thus improving the reliability of estimates on critical supersaturation and critical droplet diameter in atmospheric modelling.