The composition and sources of PM2.5 organic aerosol in two urban areas of Chile

Fine particle (PM_2.5) samples were collected, using a charcoal diffusion denuder, in two urban areas of Chile, Santiago and Temuco, during the winter and spring season of 1998. Molecular markers of the organic aerosol were determined using GC/MS. Diagnostic ratios and molecular tracers were used to investigate the origin of carbonaceous aerosols. As main sources, road and non-road engine emissions in Santiago, and wood burning in Temuco were identified. Cluster analysis was used to compare the chemical characteristics of carbonaceous aerosols between the two urban environments. Distinct differences between Santiago and Temuco samples were observed. High concentrations of isoprenoid (30–69 ng m⁻³) and unresolved complex mixture (UCM) of hydrocarbons (839–1369 ng m⁻³) were found in Santiago. High concentrations of polynuclear aromatic hydrocarbons (751±304 ng m⁻³) and their oxygenated derivatives (4±2 ng m⁻³), and of n-alk-1-enes (16±13 ng m⁻³) were observed in Temuco.     

Reproductive performance in East Greenland polar bears (Ursus maritimus) may be affected by organohalogen contaminants as shown by physiologically-based pharmacokinetic (PBPK) modelling

Polar bears (Ursus maritimus) feed mainly on ringed seal (Phoca hispida) and consume large quantities of blubber and consequently have one of the highest tissue concentrations of organohalogen contaminants (OHCs) worldwide. In East Greenland, studies of OHC time trends and organ system health effects, including reproductive, were conducted during 1990–2006. However, it has been difficult to determine the nature of the effects induced by OHC exposures on wild caught polar bears using body burden data and associated changes in reproductive organs and systems. We therefore conducted a risk quotient (RQ) evaluation to more quantitatively evaluate the effect risk on reproduction (embryotoxicity and teratogenicity) based on the critical body residue (CBR) concept and using a physiologically-based pharmacokinetic (PBPK) model. We applied modelling approaches to PCBs, p,p′-DDE, dieldrin, oxychlordane, HCHs, HCB, PBDEs and PFOS in East Greenland polar bears based on known OHC pharmacokinetics and dynamics in laboratory rats (Rattus rattus). The results showed that subcutaneous adipose tissue concentrations of dieldrin (range: 79–1271 ng g⁻¹ lw) and PCBs (range: 4128–53 923 ng g⁻¹ lw) reported in bears in the year 1990 were in the range to elicit possible adverse health effects on reproduction in polar bears in East Greenland (all RQs ⩾ 1). Similar results were found for PCBs (range: 1928–17 376 ng g⁻¹ lw) and PFOS (range: 104–2840 ng g⁻¹ ww) in the year 2000 and for dieldrin (range: 43–640 ng g⁻¹ lw), PCBs (range: 3491–13 243 ng g⁻¹ lw) and PFOS (range: 1332–6160 ng g⁻¹ ww) in the year 2006. The concentrations of oxychlordane, DDTs, HCB and HCHs in polar bears resulted in RQs < 1 and thus appear less likely to be linked to reproductive effects. Furthermore, sumRQs above 1 suggested risk for OHC additive effects. Thus, previous suggestions of possible adverse health effects in polar bears correlated to OHC exposure are supported by the present study. This study also indicates that PBPK models may be a supportive tool in the evaluation of possible OHC-mediated health effects for Arctic wildlife.     

High concentrations of persistent organic pollutants including PCBs,DDT, PBDEs and PFOS in little brown bats with white-nose syndrome in New York,USA

White-nose syndrome (WNS) is a condition associated with white fungal growth on ears, wings, and nose of hibernating bats; this condition has recently resulted in high bat mortality in the northeastern United States. Nevertheless, the pathogenesis of morbidity and mortality are still unknown. Elevated exposure to toxic contaminants could be a contributing factor via the consequent immunosuppression and endocrine disruption. In this study, diseased little brown bats (Myotis lucifugus) were collected from several hibernacula in eastern New York State in 2008. Fat tissues of bats were analyzed for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), polybrominated biphenyls (PBBs), and organochlorine pesticides (OCPs; DDT, chlordanes, HCB, and HCH), and liver was analyzed for perfluorinated compounds (PFCs). A reference population of little brown bats, not affected by WNS, was also collected from a cave in Kentucky for the analysis of trace organic contaminants. Concentration of PCBs in fat tissues of bats from New York ranged from 1900 ng g^?1 to 35 000 ng g^?1, lipid wt, with the highest concentrations found in bats collected from caves in Albany County. High concentrations of PCBs were also found in bats from Kentucky (17 100–18 400 ng g^?1, lipid wt). Total PBDE concentrations in fat tissues ranged from 520 ng g^?1 to 10 900 ng g^?1, lipid wt, in bats from New York and from 4300 ng g^?1 to 13 000 ng g^?1, lipid wt, in bats from Kentucky. High concentrations of DDT (26 900 ng g^?1, lipid wt), chlordanes (6350 ng g^?1, lipid wt), and HCB (260 ng g^?1, lipid wt) were found in bats from New York. Concentrations of hexabromobiphenyl congener 153 (PBB 153) in bats from New York ranged from 8.6 ng g^?1 to 12 4000 ng g^?1, lipid wt. Concentrations of PFCs were on the order of a few tens to a few hundreds of nanograms per gram liver, on a wet weight basis. Overall, high concentrations of PCBs, PBDEs, DDT, and chlordanes were found in fat tissues of diseased bats from New York, although the concentrations in bats from non-diseased, reference population, from Kentucky were also high.     

Recreational atmospheric pollution episodes: Inhalable metalliferous particles from firework displays

The use of fireworks creates an unusual and distinctive anthropogenic atmospheric pollution event. We report on aerosol samples collected during Las Fallas in Valencia, a 6-day celebration famous for its firework displays, and add comparative data on firework- and bonfire-contaminated atmospheric aerosol samples collected from elsewhere in Spain (Barcelona, L’Alcora, and Borriana) and during the Guy Fawkes celebrations in London. Specific high-profile official firework events during Las Fallas included the afternoon Mascletà and the nightly aerial displays (especially in the climactic final 2 days of the fiesta) and were accompanied by pollution spikes in suspended particles, NO, SO₂, and the creation and dispersal of an aerosol cloud enriched in a range of metallic elements. Notable metal aerosol concentration increases recorded during Las Fallas were potassium (from 500 to 5900 ng m⁻³), aluminium (as Al₂O₃ from around 600 to 2200 ng m⁻³), titanium (from 200 to 700 ng m⁻³), magnesium (from 100 to 500 ng m⁻³), lead (from 17 to 379 ng m⁻³), barium (from 39 to 322 ng m⁻³), strontium (from 3 to 112 ng m⁻³), copper (from 12 to 71 ng m⁻³), and antimony (from 1 to 52 ng m⁻³). Firework-contaminated aerosols of similarly metalliferous composition were also identified at the other monitoring sites, although different sites show variations attributable to other sources such as bonfires and local industry. Unusual levels of the trace elements Ba, Sr and (to a lesser extent) Cu, always in proportions with Ba dominant, along with strongly enhanced K, Pb, and Sb, are identified as being particularly characteristic of firework aerosols. Although firework-related recreational pollution episodes are transient in nature, they are highly concentrated, contribute significantly to total annual metal emissions, and are on average fine enough to be easily inhaled and a health risk to susceptible individuals.     

Concentrations of organochlorine pesticides (OCPs) residues in foodstuffs collected from traditional markets in Indonesia

A total 23 of organochlorine pesticides (OCPs) residues were determined in five groups of foodstuffs, i.e.: vegetables (carrot, potato, cucumber, corn, and onion), rice, pulses (green bean and soybean), nuts (peanut), and fish (milkfish), which collected from traditional markets in three big cities of Indonesia; Jakarta, Bogor, and Yogyakarta. OCPs were only detected in fatty foodstuffs, such as soybean, peanut, and milkfish. The concentration of HCB (expressed as ng g^?1 on a whole basis), ΣDrins, ΣDDTs, ΣHeptachlors, and ΣHCHs were in the range of <0.3–0.74 ng g^?1, <0.03–0.42 ng g^?1, <0.02–0.41 ng g^?1, <0.03–0.14 ng g^?1, and <0.03–0.06 ng g^?1, respectively, which were far below the maximum residue limits (MRLs) as established by FAO/WHO. These very low concentrations of OCPs residues in foodstuffs indicated that OCPs were used only in past time and no recent input into the environment. Furthermore, the estimated daily intake (EDI) of HCB, ΣDDTs, ΣDrins, ΣHeptachlors, and ΣHCHs in five group foodstuffs, which were 60% of total daily diet of Indonesian, were 0.09 ng kg^?1 bw d^?1, 0.04 ng kg^?1 bw d^?1, 0.01 ng kg^?1 bw d^?1, 0.003 ng kg^?1 bw d^?1, and 0.002 ng kg^?1 bw d^?1, respectively. These results were far below the acceptable daily intake (ADI) as established by FAO/WHO, which indicated that consumption of foodstuffs from Indonesia were at little risk to human health in term of OCPs at present.     

Dietary assessment of human exposure to PBDEs in South Korea

This study was conducted to measure the concentration of PBDEs in various food stuffs from Korea and to estimate levels of PBDE intake from food for the Korean population according to geographical location and age. 20 types of food samples were collected from four heavily populated cities (Seoul, Gwangju, Daejeon, Pusan) and one rural city (Gangneung) and were analyzed for 19 polybrominated diphenyl ether congeners (BDE 15, 17, 28, 33, 47, 49, 66, 71, 85, 99, 100, 119, 126, 138, 153, 154, 183, and 209).No significant differences in total PBDE levels in foods were found among four large cities (Gwangju; 10.91 ng g^?1 wet weight (ww), Seoul; 7.66 ng g^?1 ww, Daejeon; 6.91 ng g^?1 ww, Pusan; 6.87 ng g^?1 ww) and one rural city (Gangneung; 8.72 ng g^?1 ww). Daily dietary intake of PBDEs does not appear to be related to the extent of urbanization.Total dietary intake of PBDE for the average general population was 72.30 ng d^?1 (not detected (ND) = 0) which was similar to other countries. In all food groups, the largest contribution to PBDE intake was from fish and shellfish (48.96 ng d^?1). Total PBDE consumed per kilogram of body weight was estimated to range from 2.70 ng kg^?1 d^?1 for infants 1 through 2 years of age to 0.85 ng kg^?1 d for 65 years and older and was highest in young children and decreased with increasing age.     

Influence of water quality parameters on occurrence of polybrominated diphenyl ether in sediment and sediment to biota accumulation

Polybrominated diphenyl ether (PBDE) concentrations in sediment and fish from 12 principal rivers in Taiwan were investigated to determine their association with water quality parameters as well as the biota-sediment accumulation factor (BSAF) in fish with different living patterns. The highest PBDE concentration in sediment was found in the Bajhang River (261 ng g^?1 dry weight (d.w.)) and the lowest in the Beinan River and the Da-an River (0.17 ng g^?1 d.w.). The PBDE concentrations in fish samples ranged from 1.28 ng g^?1 d.w. (Oreochromis niloticus niloticus) in the Yanshuei River to 33.7 ng g^?1 d.w. (Varico rhinos barbatulus) in the Da-an River. We conclude that PBDEs contamination in sediment was significantly affected by NH₃–N, pH, and DO. The BSAF results showed a parabolic trend from low- to high-brominated BDEs. Fish easily accumulated the congeners BDE-47, -100, -119, -126, and -154 from sediment. The BSAF decreased in the following order: PeBDE > HxBDE > TeBDE > other BDEs. Principle component analysis showed that demersal fish have different PBDE sources than do pelagic fish. We conclude that living and feeding habits are critical factors affecting PBDE accumulation in fish.     

Detection,occurrence and fate of 22 psychiatric pharmaceuticals in psychiatric hospital and municipal wastewater treatment plants in Beijing,China

The liquid chromatography–electrospray ionization-tandem mass spectrometer (LC–MS/MS) method coupled with an automated solid-phase extraction procedure has been developed to identify 22 psychiatric pharmaceuticals, including seven anxiolytic-sedative-hypnotics, six antidepressants, and nine anti-schizophrenia drugs, in wastewater samples from two psychiatric hospital wastewater treatment plants (P-WWTPs) and three municipal wastewater treatment plants (M-WWTPs) in Beijing, China. Analyte recoveries from spiking experiments in the WWTP influent and effluent at three concentrations ranged from 70% to 110%, excluding sulpiride, ziprasidone, and olanzapine. Method detection limits for five, eight, and nine analytes in the WWTP influent and effluent were 20–80, 1–16, and <1 ng L^?1, respectively. High psychiatric pharmaceutical concentrations (e.g., ～942 ng L^?1oxazepam, 5552–12,782 ng L^?1 clozapine, 2762–9832 ng L^?1sulpiride, and 2030–4967 ng L^?1quetiapine) were frequently observed in P-WWTP influent compared to M-WWTPs. Although P-WWTPs typically had higher removal rates, significantly higher concentrations of the target compounds were observed in the P-WWTP secondary effluent than in the M-WWTP influent (e.g., ～752 ng L^?1oxazepam, ～8183 ng L^?1 clozapine, ～10,833 ng L^?1sulpiride, and ～1168 ng L^?1quetiapine). Thus, the discharge control of psychiatric pharmaceuticals from psychiatric hospitals requires improvement.     

Triclosan in individual human milk samples from Australia

Triclosan is a chlorinated phenol ether that has been in widespread use as a broad-spectrum antibacterial agent for four decades. When compared to the limited international data available on human body burden of triclosan, results from a pooled blood study suggested that triclosan concentrations in Australia were a factor two higher than observed in Sweden. This study determined triclosan levels in individual human milk samples (n = 151) collected between 2002 and 2005 from primiparous Australian mothers. It provided the first report of population triclosan levels and individual variation in Australia and gave a measure of infant exposure via breast feeding. The distribution of triclosan concentration was positively skewed, with 7.2% of the samples below the LOQ, 66% with a concentration of less than or equal to 1.0 ng g⁻¹ fresh weight and the remaining samples above 1 ng g⁻¹ reaching a maximum concentration of 19 ng g⁻¹ fresh weight. The mean and median triclosan concentrations were 1.3 ± 2.7 ng g⁻¹ f.w. and 0.26 ng g⁻¹ f.w., respectively. The results of this study showed high variability in triclosan concentrations between individuals and no correlations with maternal age (p = 0.094), maternal weight (p = 0.971) or infant age at the time of sample collection (p = 0.621). A large number of samples contained low or non-quantifiable concentrations of triclosan and so, in Australia, ubiquitous background exposure due to environmental sources is low. This means that body burden can be influenced by an individual’s use of triclosan containing product. Given that triclosan containing product use is continuing, it is important that monitoring in both humans and the environment is continued and that triclosan containing products are adequately labeled so that an individual can choose to avoid exposure.     

Tributyltin causes abnormal development in embryos of medaka, Oryzias latipes

We examined the effects of tributyltin (TBT) on embryonic development, hatching success and sexual differentiation in Japanese medaka (Oryzias latipes). Embryos (within 8h after fertilization) were exposed to TBT in ovo via nanoinjection at concentrations of 0 (control), 0.16, 0.80, 3.96, 19.2 and 82.1 ng/egg. Embryonic survival, development and hatching were observed. Hatched fry were reared until 60 days when they sexually matured, and sexual differentiation was also examined by accordance of genetic and phenotypic sex, based on existence of DMY (a male determining gene in medaka) and secondary sex characteristics. As results, TBT caused a concentration-dependent mortality and impaired the embryonic development. However, no masculinization was detected at 60 dph medaka adults. Lowest observed effective concentration for inducing abnormal embryonic development was estimated to 0.16 ng/egg (ca. 160 ng/g egg).     

Comprehensive assessment of pine needles as bioindicators of PAHs using multivariate analysis. The importance of temporal trends

The importance of the annual and seasonal trends associated to the polycyclic aromatic hydrocarbons (PAHs) biomonitoring by pine needles are studied with a comprehensive use of univariate and multivariate analysis tools. For this purpose, four pine needle sampling campaigns (winter, spring, summer and autumn 2007) were carried out in 29 sites from Portugal. Needles from Pinus pinaster Ait. and Pinus pinea L. trees were collected from all year-classes available in each tree, corresponding to the different shoots of needles coming out every spring and the results of both species were treated separately. Annual trends of polycyclic aromatic hydrocarbons (PAHs) contamination indicate a general increase from the least to the most exposed year-classes, for all seasons. The mean values for the sum of 16 PAHs ranged from 71 ± 33 ng g⁻¹ (dry weight – dw) for new year (2007) needles in the summer to 514 ± 317 ng g⁻¹ (dw) for 2-year needles (2005) in the spring for P. pinea, and between 90 ± 50 ng g⁻¹ (dw) for new year (2007) needles in the summer and 1212 ± 436 ng g⁻¹ (dw) for 3-year needles (2004) in summer for P. pinaster. The seasonal evolution shows the highest concentrations in the winter, then declining to the lowest levels in the summer and rising again from summer to autumn. Principal component analysis confirmed differences between seasons and needle year-classes, more visible for P. pinea samples. The cooler seasons have more affinity towards the lighter more abundant PAHs, as do the older needles. Differences between both pine species are also evident.     

Polychlorinated biphenyl spatial patterns in San Francisco Bay forage fish

Industrialized waterways frequently contain nearshore hotspots of legacy polychlorinated biphenyl (PCB) contamination, with uncertain contribution to aquatic food web contamination. We evaluated the utility of estuarine forage fish as biosentinel indicators of local PCB contamination across multiple nearshore sites in San Francisco Bay. Topsmelt (Atherinops affinis) or Mississippi silverside (Menidia audens) contamination was compared between 12 targeted sites near historically polluted locations and 17 probabilistically chosen sites representative of ambient conditions. The average sum of 209 PCB congeners in fish from targeted stations (441 ± 432 ng g^?1 wet weight, mean ± SD) was significantly higher than probabilistic stations (138 ± 94 ng g^?1). Concentrations in both species were comparable to those of high lipid sport fish in the Bay, strongly correlated with spatial patterns in sediment contamination, and above selected literature thresholds for potential hazard to fish and wildlife. The highest concentrations were from targeted Central Bay locations, including Hunter’s Point Naval Shipyard (1347 ng g^?1; topsmelt) and Stege Marsh (1337 ng g^?1; silverside). Targeted sites exhibited increased abundance of lower chlorinated congeners, suggesting local source contributions, including Aroclor 1248. These findings indicate that current spatial patterns in PCB bioaccumulation correlate with historical sediment contamination due to industrial activity. They also demonstrate the utility of naturally occurring forage fish as biosentinels of localized PCB exposure.     

Pesticides analysed in rainwater in Alsace region (Eastern France): Comparison between urban and rural sites

Current-used pesticides commonly applied in Alsace region (Eastern France) on diverse crops (maize, vineyard, vegetables, etc.) were analysed, together with Lindane, in rainwater between January 2002 and June 2003 simultaneously on two sites situated in a typical rural (Erstein, France) and urban area (Strasbourg, France).Rainwater samples were collected on a weekly basis by using two automatic wet only collectors associated with an open collector for the measurement of rainwater height.Pesticides were analysed by GC-MSMS and extracted from rainwater by SPME. Two runs were performed. The first one was performed by using a PDMS (100 μm) fibre for pesticides where direct injection into GC is possible (alachlor, atrazine, azinphos-ethyl, azinphos-methyl, captan, chlorfenvinphos, dichlorvos, diflufenican, α- and β-endosulfan, iprodione, lindane, metolachlor, mevinphos, parathion-methyl, phosalone, phosmet, tebuconazole, triadimefon and trifluralin). The second run was performed by using PDMS/DVB fibre and this run concerns pesticides where a preliminary derivatisation step with pentafluorobenzylbromide (PFBBr) is required for very low volatiles (bromoxynil,2,4-MCPA, MCPP and 2,4-D) or thermo labiles (chlorotoluron, diuron and isoproturon) pesticides.Results showed that the more concentrated pesticides detected were those used as herbicides in large quantities in Alsace region for maize crops (alachlor, metolachlor and atrazine). Maximum concentrations for these herbicides have been measured during intensive applications periods on maize crops following by rapid decrease immediately after use.For Alachlor, most important peaks have been observed between 21 and 28 April 2003 (3327 ng L⁻¹ at Erstein and 5590 ng L⁻¹ at Strasbourg). This is also the case for Metolachlor where most important peak was observed during the same week.Concentrations of pesticides measured out of application periods were very low for many pesticides and some others where never detected during this period. This is the case for diflufenican which was detected only during application. Two important peaks of concentrations were observed; a first one (101 ng L⁻¹) in Erstein in November 2002 (4–11 November) and a second one (762 ng L⁻¹) also in Erstein (28 April–15 May).The same behaviour can be seen for chlorfenvinphos and phosalone which have been detected, respectively, 2 and 4 times in Erstein and Strasbourg at high concentrations (28 April 2003–15 May 2003, 187 ng L⁻¹ of phosalone and 157 ng L⁻¹ of chlorfenvinphos in Erstein).MCPP, 2,4 MCPA and 2,4-D have been detected at high concentrations in rainwater but for the other pesticides very episodically and mainly during their use in agriculture. Maximal concentrations of MCPP and 2,4 MCPA have been measured in Erstein between 28 April and 15 May (904 and 746 ng L⁻¹, respectively).Comparison between rural and urban sites showed that concentrations in rural areas are generally higher except for pesticides commonly applied in urban areas like Diuron.No seasonal phenomenon was observed for Diuron. This herbicide has been detected in practically all of the rainwater samples in Strasbourg (40/41) with a maximum of 1025 ng L⁻¹ (16–23 September 2002) in 38 samples on 41 in Erstein with a maximum of 317 ng L⁻¹ (15–23 October 2002). The total concentration of Diuron measured between 4 March 2002 and 20 July 2003 is of 4721 ng L⁻¹ in Strasbourg and 5025 ng L⁻¹ in Erstein. This result shows that wet deposition of Diuron in urban and rural sites was equivalent and can be explained by the “urban use” of this molecule together with its potential persistence.     

Mercury emissions from automobiles using gasoline,diesel, and LPG

Mercury (Hg) emissions from gasoline, diesel, and liquefied petroleum gas (LPG) vehicles were measured and speciated (particulate, oxidized, and elemental mercury). First, three different fuel types were analyzed for their original Hg contents; 571.1±4.5 ng L⁻¹ for gasoline, 185.7±2.6 ng L⁻¹ for diesel, and 1230.3±23.5 ng L⁻¹ for LPG. All three vehicles were then tested at idling and driving modes. Hg in the exhaust gas was mostly in elemental form (Hg⁰), and no detectable levels of particulate (Hg^p) or oxidized (Hg²⁺) mercury were measured. At idling modes, Hg concentrations in the exhaust gas of gasoline, diesel, and LPG vehicles were 1.5–9.1, 1.6–3.5, and 10.2–18.6 ng m⁻³, respectively. At driving modes, Hg concentrations were 3.8–16.8 ng m⁻³ (gasoline), 2.8–8.5 ng m⁻³ (diesel), and 20.0–26.9 ng m⁻³ (LPG). For all three vehicles, Hg concentrations at driving modes were higher than at idling modes. Furthermore, Hg emissions from LPG vehicle was highest of all three vehicle types tested, both at idling and driving modes, as expected from the fact that it had the highest original fuel Hg content.     

Comparison of organic compositions in dust storm and normal aerosol samples collected at Gosan,Jeju Island,during spring 2005

To better understand the current physical and chemical properties of East Asian aerosols, an intensive observation of atmospheric particles was conducted at Gosan site, Jeju Island, South Korea during 2005 spring. Total suspended particle (TSP) samples were collected using pre-combusted quartz filters and a high-volume air sampler with the time intervals ranging from 3 h to 48 h. The kinds and amount of various organic compounds were measured in the samples using gas chromatography–mass spectrometry. Among the 99 target compounds detected, saccharides (average, 130 ± 14 ng m^?3), fatty acids (73 ± 7 ng m^?3), alcohols (41 ± 4 ng m^?3), n-alkanes (32 ± 3 ng m^?3), and phthalates (21 ± 2 ng m^?3) were found to be major compound classes with polyols/polyacids, lignin and resin products, PAHs, sterols and aromatic acids being minor. Compared to the previous results reported for 2001 late spring samples, no significant changes were found in the levels of their concentrations and compositions for 4 years, although the economy in East Asia, especially in China, has sharply expanded from 2001 to 2005. During the campaign at Gosan site, we encountered two distinct dust storm episodes with high TSP concentrations. The first dust event occurred on March 28, which was characterized by a predominance of secondary organic aerosols. The second event that occurred on the next day (March 29) was found to be characterized by primary organic aerosols associated with forest fires in Siberia/northeastern China. A significant variation in the molecular compositions, which was found within a day, suggests that the compositions of East Asian aerosols are heterogeneous due to multi-contributions from different source regions together with different pathways of long-range atmospheric transport of particles.     

Acetone and monoterpene emissions from the boreal forest in northern Europe

Acetone is a ubiquitous component of the atmosphere which, by its photolysis, can play an important role in photochemical reactions in the free troposphere. This paper investigates the biogenic source of acetone from Scots pine (Pinus sylvestris) and Norway spruce (Picea abies) in the Scandinavian boreal zone. Branch emission measurements of acetone, monoterpenes, and isoprene were made with an all-Teflon flow-through branch chamber from five specimens of Scots pine at three sites in Sweden and Finland, and from one specimen of Norway spruce at one site in Sweden. Acetone samples were taken with SepPak™ DNPH cartridges, monoterpenes with Tenax TA, and isoprene with 3 l electropolished canisters. Acetone was found to dominate the carbonyl emission of both Scots pine and Norway spruce, as large as the monoterpene emissions and for Norway spruce, as the isoprene emission. The average standard emission rate (30°C) and average β-coefficient for the temperature correlation for 5 specimens of Scots pine were 870 ng C gdw⁻¹ h⁻¹ (gdw=gram dry weight) and 0.12, respectively. For the monoterpenes the values were 900 ng C gdw⁻¹ h⁻¹ and 0.12, respectively. The standard emission rate (30°C) for acetone from Norway spruce was 265 ng C gdw⁻¹ h⁻¹, but the sparsity of data, along with the unusual weather conditions at the time of the measurements, precludes the establishment of a summertime best estimate emission factor.     

Engine dynamometer experiments: platinum emissions from differently aged three-way catalytic converters

Depending on the operating conditions and the age of the converter, mean platinum emissions ranged from 7 to 123 ng m^-3 corresponding to emission factors between 9 and 124 ng km^-1. There were no statistically significant differences between the four converter brands tested. The data from new (12–90 ng km^-1) and old catalytic converters (9–26 ng km^-1) installed on a medium-powered gasoline engine (1.8 l 66 kW) showed a tendency towards decreasing platinum emission with increasing use. The platinum emissions increased with rising simulated speed and exhaust temperature. The lowest mean emission from new converters (12 ng km^-1) was found at a constant speed of 80 km h^-1, the highest (90 ng km^-1) at 130 km h^-1. Using the US72 or the US72-EUDC test cycles the emission factors were higher (37 or 19 ng km^-1) than at 80 km h^-1 indicating that additional mechanical or thermal impacts enhance the platinum abrasion at cycle conditions. After installing catalytic converters tested with the 1.8 l engine on a smaller engine (1.4 l 44 kW), the platinum emissions measured at the US72 cycle and a high-speed condition (140 km h^-1) were only 9 and 22 ng km^-1, respectively. Platinum is almost exclusively emitted bound to aluminum oxide particles where (depending on the driving conditions) 43–74% of these emitted particles had aerodynamic diameters >10 μm. The alveolar fraction (<3 μm) was between 11 and 26% (1.8 l engine) and between 21 and 36% (1.4 l engine). If at all, soluble platinum is emitted in only very small quantities (⩽1%).     

Identification,abundance and seasonal variation of anthropogenic organic aerosols from a mega-city in China

PM_2.5 aerosols were collected in Nanjing, a typical mega-city in China, during summer and winter 2004 and were characterized for aromatic and cyclic compounds using a GC/MS technique to understand the air pollution problem. They include polycyclic aromatic hydrocarbons (PAHs), hopanes, phthalates and hydroxy-PAHs (OH-PAHs). PAHs, hopanes and OH-PAHs presented higher concentrations in winter (26–178, 3.0–18, and 0.013–0.421 ng m⁻³, respectively) than in summer (12–96, 1.6–11, and 0.029–0.171 ng m⁻³, respectively) due to an enhanced coal burning for house heating and atmospheric inversion layers developed in the cold season. In contrast, phthalates are more abundant in summer (109–368 ng m⁻³, average 230 ng m⁻³) than in winter (33–390 ng m⁻³, average 170 ng m⁻³) due to an enhanced evaporation from plastics during the hot season and the subsequent deposition on the pre-existing particles. Generally, all the identified compounds showed higher concentrations in nighttime than in daytime due to inversion layers and increased emissions from heavy-duty trucks at night. PAHs, hopanes and phthalates in Nanjing aerosols are 5–100 times more abundant than those in Los Angeles, USA, indicating a serious air pollution problem in the city. Concentrations of OH-PAHs are 1–3 orders of magnitude less than their parent PAHs and comparable to those reported from other international cities. Source identification using diagnostic ratios of the organic tracers suggests that PAHs in Nanjing urban area are mainly derived from coal burning, whereas hopanes are more attributable to traffic emissions.