Abstract:The complexes RuCl 2 (PCy 3 ) 2 (=CHPh), 1, and RuCl 2 (PCy 3 )(H 2 IMes)(=CHPh), 2, proved to be active catalysts for the self-metathesis of oleate-type fatty compounds containing the ester, hydroxyl, epoxy and carboxylic acid functional groups. At elevated reaction temperatures 2 showed a higher activity, stability and lower selectivity for primary metathesis products compared to 1. A profound influence of organic functional groups on catalyst activity and selectivity was found and from relative activities and selectivities 2 has proved to be more resistant to deactivation by polar functional groups and more inclined to promote double bond isomerisation than 1. The observed catalyst deactivation by oxygen-containing functional groups could be attributed to a phosphine displacement side reaction.

This study aimed to characterise aerosols sampled in the vicinity of a major industrialised area, i.e. the Vaal Triangle. It included thedetermination of oxidative potential as a predictive indicator of particle toxicity. Aerosol samples were collated through the cascadefiltering during an eight-month period (12 h over three days in one week). Three size fractions were analysed for organic carbon(OC), black carbon (BC) and oxidative potential (OP), while ionic content was presented as monthly and seasonal concentrations. Thecontinuous measurement of black carbon by an optical attenuation instrument was collated concurrently with cascade filtering. Thecarbonaceous content was low compared to the ionic one. Within the carbonaceous concentrations, the organic carbon was higherthan concentrations of black carbon in both seasons in the ultra-fine fraction; the opposite was the case for the fine fraction, whilethe coarse fraction concentrations of organic carbon in the dry season had higher concentrations than black carbon in the wet seasonand organic carbon in the wet season. The OP tended to increase as the size was decreasing for wet season aerosols, whereas, forthe dry season, the highest OP was exerted by the fine fraction. The ultrafine fraction was the one showing the most contrasting OPbetween the two seasons. Continuous monitoring indicated that the higher BC concentrations were recorded in the dry/winter partof the year, with the daily pattern of concentrations being typically bimodal, having both the morning and evening peaks in bothseasons. Within the ionic content, the dominance of sulphate, nitrate and ammonium was evident. Multiple linear correlations wereperformed between all determined compounds. Strong correlations of carboxylic acids with other organic compounds were revealed.These acids point to emissions of VOC, both anthropogenic and biogenic. Since they were equally present in both seasons, a mixtureof sources was responsible, both present in the wider area and throughout the year.

Abstract. Naturally and anthropogenically emitted aerosols, which are determined by their physical and chemical properties, have an impact on both air quality and the radiative properties of the earth. An important source of atmospheric particulate matter (PM) in South Africa is household combustion for space heating and cooking, which predominantly occurs in low-income urban settlements. The aim of this study was to conduct a detailed size-resolved assessment of chemical characteristics of aerosols associated with household combustion through the collection of particulates in low-income urban settlements in South Africa in order to quantify the extent of the impacts of atmospheric pollution within these settlements. Outdoor (ambient) and indoor aerosols in different size fractions were collected during summer and winter in four low-income urban settlements located in the north-eastern interior on the South African Highveld. The mass concentration and chemical composition was determined for three size fractions, namely, PM1, PM2.5 and PM2.5-10. The highest concentrations of particulates were measured indoors with the highest mass concentration determined in the indoor PM2.5-10 (coarse) size fraction. However, the highest mass concentrations were determined in PM1 in all outdoor aerosol samples collected during winter and summer, as well as in indoor samples collected during summer. Significantly higher concentrations were determined for SO4−2 in outdoor and indoor particulates compared to other ionic species, with NH4+ and NO3− being the second most abundant. SO4−2 and NH4+ almost exclusively occurred in the PM1 size fraction, while NO3− was the major constituent in the larger size fractions. The highest SO4−2 levels were recorded for the winter and summer outdoor campaigns conducted at Zamdela, while NO3− and NH4+ concentrations were higher during the winter outdoor campaign. The combined concentrations of trace elements were higher for indoor particulates compared to outdoor aerosols, while the total trace element concentrations in PM1 were substantially higher than levels thereof in the two larger size fractions of particulates collected during all sampling campaigns. No distinct seasonal trend was observed for the concentrations of trace elements. Na, Ca and Cr had the highest concentrations in particulates collected during outdoor and indoor sampling campaigns. Ni concentrations in outdoor and indoor aerosols exceeded the annual average European standard PM1 collected during all sampling campaigns in low-income urban settlements had the highest organic- and elemental carbon (OC and EC) concentrations. The highest OC and EC levels were determined in PM1 collected during the winter indoor campaign. OC and EC concentrations were highest during winter, which can be attributed to changes in meteorological patterns and increased household combustion during winter. Low OC / EC ratios determined for particulates collected in low-income urban settlements are indicative of OC and EC being mainly associated with local sources of these species. OC concentrations determined in this study were an order of magnitude lower than OC concentrations determined for ambient aerosols collected in the north-eastern interior of South Africa, while similar EC levels were measured. According to estimated dust concentrations, it was indicated that dust is the major constituent in all size ranges of particulates collected in this study, while trace elements were the second most abundant. However, trace elements made the highest contribution to indoor PM1 and PM1-2.5 mass. Mass concentrations and chemical concentrations determined for aerosols collected in low-income settlements reflects the regional impacts of anthropogenic sources in the north-eastern interior of South Africa, as well as the influence of local sources.

Abstract. Naturally and anthropogenically emitted aerosols, which are determined by their physical and chemical properties, have an impact on both air quality and the radiative properties of the earth. An important source of atmospheric particulate matter (PM) in South Africa is household combustion for space heating and cooking, which predominantly occurs in low-income urban settlements. The aim of this study was to conduct a detailed size-resolved assessment of chemical characteristics of aerosols associated with household combustion through the collection of particulates in low-income urban settlements in South Africa to quantify the extent of the impacts of atmospheric pollution. Outdoor (ambient) and indoor aerosols in different size fractions were collected during summer and winter in four low-income urban settlements located in the north-eastern interior on the South African Highveld, i.e. Kwadela, Kwazamokuhle, Zamdela, and Jouberton. Mass concentration and chemical composition was determined for three size fractions, namely, PM1, PM2.5, and PM2.5−10. The highest concentrations of particulates were measured indoors with the highest mass concentration determined in the indoor PM2.5−10 (coarse) size fraction. However, the highest mass concentrations were determined in PM1 in all outdoor aerosol samples collected during winter and summer, and in indoor samples collected during summer. Significantly higher concentrations were determined for SO4-2 in outdoor and indoor particulates compared to other ionic species, with NH4+ and NO3- being the second most abundant. SO4-2 and NH4+ almost exclusively occurred in the PM1 size fraction, while NO3- was the major constituent in the larger size fractions. The highest SO4-2 levels were recorded for the winter and summer outdoor campaigns conducted at Zamdela, while NO3- and NH4+ concentrations were higher during the winter outdoor campaign. The combined concentrations of trace elements were higher for indoor particulates compared to outdoor aerosols, while the total trace element concentrations in PM1 were substantially higher than levels thereof in the two larger size fractions of particulates collected during all sampling campaigns. No distinct seasonal trend was observed for the concentrations of trace elements. Na, Ca, and Cr had the highest concentrations in particulates collected during outdoor and indoor sampling campaigns. Ni concentrations in outdoor and indoor aerosols exceeded the annual average European standard. PM1 collected during all sampling campaigns in low-income urban settlements had the highest organic carbon (OC) and elemental carbon (EC) concentrations. The highest OC and EC levels were determined in PM1 collected during the winter indoor campaign. OC and EC concentrations were highest during winter, which can be attributed to changes in meteorological patterns and increased household combustion during winter. Low OC/EC ratios determined for particulates collected in low-income urban settlements are indicative of OC and EC being mainly associated with local sources of these species. OC concentrations determined in this study were an order of magnitude lower than OC concentrations determined for ambient aerosols collected in the north-eastern interior of South Africa, while similar EC levels were measured. According to estimated dust concentrations, it was indicated that dust is the major constituent in all size ranges of particulates collected in this study, while trace elements were the second most abundant. However, trace elements made the highest contribution to indoor PM1 and PM1−2.5 mass. Mass concentrations and chemical concentrations determined for aerosols collected in low-income settlements reflect the regional impacts of anthropogenic sources in the north-eastern interior of South Africa and the influence of local sources.