Abstract. This study investigates the contribution of potential sources to the submicron (PM 1 ) organic aerosol (OA) simultaneously detected at an urban background (UB) and a road site (RS) in Barcelona during the 30 days of the intensive field campaign of SAPUSS (Solving Aerosol Problems by Using Synergistic Strategies, September-October 2010). A total of 103 filters at 12 h sampling time resolution were collected at both sites. Thirty-six neutral and polar organic compounds of known emission sources and photo-chemical transformation processes were analyzed by gas chromatography-mass spectrometry (GC-MS). The concentrations of the trace chemical compounds analyzed are herein presented and discussed.Additionally, OA source apportionment was performed by multivariate curve resolution-alternating least squares (MCR-ALS) and six OA components were identified at both sites: two were of primary anthropogenic OA origin and three of secondary OA origin, while a sixth one was not clearly defined. Primary organics from emissions of local anthropogenic activities (urban primary organic aerosol, or POA Urban), mainly traffic emissions but also cigarette smoke, contributed 43 % (1.5 µg OC m −3 ) and 18 % (0.4 µg OC m −3 ) to OA at RS and UB, respectively. A secondary primary source -biomass burning (BBOA) -was found in all the samples (average values 7 % RS; 12 % UB; 0.3 µg OC m −3 ), but this component was substantially contributing to OA only when the sampling sites were under influence of regional air mass circulation (REG.). Three secondary organic aerosol (SOA) components (describing overall 60 % of the variance) were observed in the urban ambient PM 1 . Products of isoprene oxidation (SOA ISO) -i.e.2-methylglyceric acid, C 5 alkene triols and 2-methyltetrols -showed the highest abundance at both sites when the city was under influence of inland air masses. The overall concentrations of SOA ISO were similar at both sites (0.4 and 0.3 µg m −3 , or 16 % and 7 %, at UB and RS, respectively). By contrast, a SOA biogenic component attributed to α-pinene oxidation (SOA BIO PIN) presented average concentrations of 0.5 µg m −3 at UB (24 % of OA) and 0.2 µg m −3 at RS (7 %), respectively, suggesting that this SOA component did not impact the two monitoring sites at the same level. A clear anti-correlation was observed between SOA ISO and SOA PIN during nucleation days, surprisingly suggesting that some of the growth of urban freshly nucleating particles may be driven by biogenic α-pinene oxidation products but inhibited by isoprene organic compounds. A third SOA component was formed by a mixture of aged anthropogenic and biogenic secondary organic compounds (SOA Aged) that accumulated under stagnant atmospheric conditions, contributing for 12 % to OA at RS (0.4 µg OC m −3 ) and for 18 % at UB (0.4 µg OC m −3 ).A sixth component, formed by C 7 -C 9 dicarboxylic acids and detected especially during daytime, was called "urban oxygenated organic aerosol" (OOA Urban) due to its high abundance at urban RS (23 %; 0.8 µg OCm −3 ) vs. ...

Exposure to PAHs, and in particular to BPA, is associated with subclinical changes on the caudate nucleus, even below the legislated annual target levels established in the European Union. The behavioral consequences of this induced brain change were not identified in this study, but given the caudate nucleus involvement in many crucial cognitive and behavior processes, this volume reduction is concerning for the children's neurodevelopment.

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DAURE (Determination of the Sources of Atmospheric Aerosols in Urban and Rural Environments in the Western Mediterranean) was a multidisciplinary international field campaign aimed at investigating the sources and meteorological controls of particulate matter in the Western Mediterranean Basin (WMB). Measurements were simultaneously performed at an urban-coastal (Barcelona, BCN) and a rural-elevated (Montseny, MSY) site pair in NE Spain during winter and summer. State-of-the-art methods such as 14 C analysis, proton-transfer reaction mass spectrometry, and high-resolution aerosol mass spectrometry were applied for the first time in the WMB as part of DAURE. WMB regional pollution episodes were associated with high concentrations of inorganic and organic species formed during the transport to inland areas and built up at regional scales. Winter pollutants accumulation depended on the degree of regional stagnation of an air mass under anticyclonic conditions and the planetary boundary layer height. In summer, regional recirculation and biogenic secondary organic aerosols (SOA) formation mainly determined the regional pollutant concentrations. The contribution from fossil sources to organic carbon (OC) and elemental carbon (EC) and hydrocarbon-like organic aerosol concentrations were higher at BCN compared with MSY due to traffic emissions. The relative contribution of nonfossil OC was higher at MSY especially in summer due to biogenic emissions. The fossil OC/EC ratio at MSY was twice the corresponding ratio at BCN indicating that a substantial fraction of fossil OC was due to fossil SOA. In winter, BCN cooking emissions were identified as an important source of modern carbon in primary organic aerosol.

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Background:Traffic-related air pollution is emerging as a risk factor for Alzheimer's disease (AD) and impaired brain development. Individual differences in vulnerability to air pollution may involve the ε4 allele of Apolipoprotein E (APOE) gene, the primary genetic risk factor for AD.Objective:We analyzed whether the association between traffic air pollution and neurodevelopmental outcomes is modified by APOE ε4 status in children.Methods:Data on parent-reported behavior problems (total difficulties scores, Strengths and Difficulties Questionnaire), teacher-reported attention-deficit hyperactivity disorder (ADHD) symptom scores, cognitive performance trajectories (computerized tests of inattentiveness and working memory repeated 2–4 times during January 2012–March 2013), and APOE genotypes were obtained for 1,667 children age 7–11 y attending 39 schools in or near Barcelona. Basal ganglia volume (putamen, caudate, and globus pallidum) was measured in 163 of the children by MRI (October 2012–April 2014.) Average annual outdoor polycyclic aromatic hydrocarbons (PAHs), elemental carbon (EC), and nitrogen dioxide (NO2) concentrations were estimated based on measurements at each school (two 1-wk campaigns conducted 6 months apart in 2012).Results:APOE ε4 allele carriers had significantly higher behavior problem scores than noncarriers, and adverse associations with PAHs and NO2 were stronger or limited to ε4 carriers for behavior problem scores (P-interaction 0.03 and 0.04), caudate volume (P-interaction 0.04 and 0.03), and inattentiveness trajectories (P-interaction 0.15 and 0.08, respectively). Patterns of associations with the same outcomes were similar for EC.Conclusion:PAHs, EC, and NO2 were associated with higher behavior problem scores, smaller reductions in inattentiveness over time, and smaller caudate volume in APOE ε4 allele carriers in our study population, and corresponding associations were weak or absent among ε4 noncarriers. These findings support a potential role of APOE in biological mechanisms that may contribute to associations between air pollution and neurobehavioral outcomes in children. https://doi.org/10.1289/EHP2246

Soil-air partitioning is one of the key processes controlling the regional and global cycling and storage of polycyclic aromatic hydrocarbons (PAHs). However, the specific processes dominating the partitioning of PAHs between these two environmental compartments still need to be elucidated. Stable and distinct atmospheric conditions paralleling different soil properties are found at Tenerife island (28 degrees 18'N, 16 degrees 29'W), which is located in permanent inversion layer conditions, and they provide interesting model cases for the study of air-soil partitioning. Analysis of phenanthrene, pyrene, fluoranthene, and chrysene showed concentrations 4- to 10-fold higher below than above the inversion layer. Similarly, soil total organic carbon (TOC) and black carbon (BC) were 11 and 3 times higher, respectively, below the inversion layer than above. The octanol-air partition coefficient (K(OA)) derived model provides a good description of PAH soil-air partitioning coefficients (K(P)) below the inversion layer but underpredicts them in the area dominated by deposition of long-range transported aerosols without inputs of organic matter from local vegetation. Inclusion of soot carbon in the soil-air partitioning model results in good agreement between predicted and measured K(P) in this area but in overpredicted K(P) values for the soils under the vegetation cover, which shows that the influence of soil soot carbon on PAH air-soil partitioning depends on its abundance relative to soil organic carbon. Absorption into organic matter is the dominant process in soils containing high organic carbon concentrations, whereas adsorption onto soot carbon becomes relevant in soils with low organic carbon and high soot content.