Aerosol sources in subway environments.

Millions of people use rail subway public transport around the world, despite the relatively high particulate matter (PM) concentrations in these underground environments, requiring the identification and quantification of the aerosol source contributions to improve the air quality. An extensive aerosol monitoring campaign was carried out in eleven subway stations in the Barcelona metro system, belonging to seven subway lines. PM2.5 samples were collected during the metro operating hours and chemically analysed to determine major and trace elements, inorganic ions, and total carbon. The chemical compositions of subway components such as brake pads, rail tracks and pantographs were also determined. The mean PM2.5 concentrations varied widely among stations, ranging from 26 µg m-3 to 86 µg m-3. Subway PM2.5 was mainly constituted by Fe2O3 (30-66%), followed by carbonaceous matter (18-37%) for the old stations, while for new stations equipped with Platform Screen Doors (PSD) these percentages go down to 21-44% and 15-30%, respectively. Both the absolute concentrations and the relative abundance of key species differed for each subway station, although with common patterns within a given subway line. This is a result of the different emission chemical profiles in different subway lines (using diverse types of brakes and/or pantographs). The co-emission of different sources poses a problem for their separation by receptor models. Nevertheless, receptor modelling (Positive Matrix Factorization) was applied resulting in ten sources, five of them subway-specific: RailWheel, RailWheel+Brake, Brake_A, Brake_B, Pb. The sum of their contributions accounted for 43-91% of bulk PM2.5 for the old stations and 21-52% for the stations with PSD. The decrease of the activity during the weekends resulted in a decrease (up to 56%) in the subway-specific sources contribution to the -already lower- bulk PM2.5 concentrations compared to weekdays. The health-related elements are mainly apportioned (> 60%) by subway sources.

Bioaerosols in the Barcelona subway system.

Subway systems worldwide transport more than 100 million people daily; therefore, air quality on station platforms and inside trains is an important urban air pollution issue. We examined the microbiological composition and abundance in space and time of bioaerosols collected in the Barcelona subway system during a cold period. Quantitative PCR was used to quantify total bacteria, Aspergillus fumigatus, influenza A and B, and rhinoviruses. Multitag 454 pyrosequencing of the 16S rRNA gene was used to assess bacterial community composition and biodiversity. The results showed low bioaerosol concentrations regarding the targeted microorganisms, although the bacterial bioburden was rather high (104 bacteria/m3 ). Airborne bacterial communities presented a high degree of overlap among the different subway environments sampled (inside trains, platforms, and lobbies) and were dominated by a few widespread taxa, with Methylobacterium being the most abundant genus. Human-related microbiota in sequence dataset and ascribed to potentially pathogenic bacteria were found in low proportion (maximum values below 2% of sequence readings) and evenly detected. Hence, no important biological exposure marker was detected in any of the sampled environments. Overall, we found that commuters are not the main source of bioaerosols in the Barcelona subway system.

The LUCIA beamline at SOLEIL.

Commissioned in May 2004 on the SLS machine, the LUCIA beamline was moved to the synchrotron SOLEIL during the summer of 2008. To take advantage of this new setting several changes to its design were introduced. Here, a review of the various improvements of the mechanics and, mostly, of the optics is given. Described in detail are the results of a new multilayer grating monochromator implemented on the Kohzu vessel already holding the two-crystal set-up. It consists of a grating grooved onto a multilayer (replacing the first crystal) associated to a multilayer (as a second crystal). It allows a shift of the low-energy limit of the beamline to around 500 eV with an energy resolution and a photon flux comparable with those of the previous couples of crystals (KTP and beryl).

Open air mineral treatment operations and ambient air quality: assessment and source apportionment.

We present a methodology for evaluating and quantifying the impact of inhalable mineral dust resuspension close to a potentially important industrial point source, in this case an open air plant producing sand, flux and kaolin in the Capuchinos district of Alcañiz (Teruel, NE Spain). PM(10) levels at Capuchinos were initially high (42 µg m(-3) as the annual average with 91 exceedances of the EU daily limit value during 2007) but subsequently decreased (26 µg m(-3) with 16 exceedances in 2010) due to a reduced demand for minerals from the ceramic industry and construction sector during the first stages of the economic crisis. Back trajectory and local wind pattern analyses revealed only limited contribution from exotic PM sources such as African dust intrusions whereas there was clearly a strong link with the mineral stockpiles of the local industry. This link was reinforced by chemical and mineral speciation and source apportionment analysis which showed a dominance of mineral matter (sum of CO(3)(2-), SiO(2), Al(2)O(3), Ca, Fe, K, Mg, P, and Ti: mostly aluminosilicates) which in 2007 contributed 76% of the PM(10) mass (44 µg m(-3) on average). The contribution from Secondary Inorganic Aerosols (SIA, sum of SO(4)(2-), NO(3)(-) and NH(4)(+)) reached 8.4 µg m(-3), accounting for 14% of the PM(10) mass, similar to the amount of calcareous road dust estimated to be present (8 µg m(-3); 13%). Organic matter and elemental carbon contributed 5.3 µg m(-3) (9%) whereas marine aerosol (Na + Cl) levels were minor with an average concentration of 0.4 µg m(-3) (1% of the PM(10) mass). Finally, chemical and mineralogical analysis of stockpile samples and comparison with filter samples confirmed the local industry to be the major source of ambient PM(10) in the area.

Within-city contrasts in PM composition and sources and their relationship with nitrogen oxides.

The present work is part of the INMA (INfancia y Medio Ambiente -'Environment and Childhood') project, which aims at assessing the adverse effects of exposure to air pollution during pregnancy and early in life. The present study was performed in the city of Sabadell (Northeast Spain) at three sampling sites covering different traffic characteristics, during two times of the year. It assesses time and spatial variations of PM(2.5) concentrations, chemical components and source contributions, as well as gaseous pollutants. Furthermore, a cross-correlation analysis of PM components and source contributions with gaseous pollutants used as a proxy for exposure assessment is carried out. Our data show the influence of traffic emissions in the Sabadell area. The main PM sources identified by Positive Matrix Factorisation (PMF) were similar between the two seasons: mineral source (traffic-induced resuspension, demolition/construction and natural background), secondary sulphate (higher in summer), secondary nitrate (only during winter), industrial, and road traffic, which was the main contributor to PM(2.5) at two of the sites. The correlation of concentrations of nitrogen oxides was especially strong with those of elemental carbon (EC). The relatively weaker correlations with organic carbon (OC) in summer are attributed to the variable formation of secondary OC. Strong correlations between concentration of nitrogen oxides and PM(2.5) road traffic contributions obtained from source apportionment analysis were seen at all sites. Therefore, under the studied urban environment, nitrogen oxides can be used as a proxy for the exposure to road traffic contribution to PM(2.5); the use of NO(x) concentrations being preferred, with NO and NO(2) as second and third options, respectively.

Airborne microplastic particle concentrations and characterization in indoor urban microenvironments.

Airborne microplastics (MPs) have recently drawn the attention of the scientific community due to their possible human inhalation risk. Indoor environments are of relevance as people spend about 90% of their time indoors. This study evaluated MPs concentrations in three indoor environments: houses, public transport and working places, which are representative of urban life. Sampling involved the collection of airborne particulate matter on nylon 20 µm pore size filters. Samples were first visually inspected, and particles were characterized (colour, length or area). Polymer identification was performed through µFTIR analysis. Working conditions were controlled to guarantee quality assurance and avoid background contamination. Limits of detection, recovery tests and repeatability were performed with home-made polyethylene (PE), polypropylene (PP), and polystyrene (PS) standards. The highest average MP concentrations were found in buses (17.3 ± 2.4 MPs/m3) followed by 5.8 ± 1.9 MPs/m3 in subways, 4.8 ± 1.6 MPs/m3 in houses, and 4.2 ± 1.6 MPs/m3 in the workplaces. Polyamide, PA (51%), polyester PES (48%) and PP (1%) were the polymers identified and most common in personal care products and synthetic textiles. Most of these polymers were below 100 µm in size for both fibres (64 ± 8%) and fragments (78 ± 11%). The frequency of MP particles in our study decreased with increasing size, which points to their potential as an inhalation hazard.

Exposure of e-waste dismantlers from a formal recycling facility in Spain to inhalable organophosphate and halogenated flame retardants.

Concentration levels of 16 organophosphate esters (OPEs) and 18 halogenated flame retardants (HFRs) were measured in airborne fine particulate matter (PM2.5) from an e-waste dismantling facility in Catalonia (Spain) to assess their occurrence, profiles and potential health risks. Three different areas from the facility were studied, including an area for cathodic ray-tube (CRT) TV dismantling, a grinding area, and the outdoor background. OPEs and HFRs were detected in all samples, with concentrations between 10.4 and 110 ng/m3 for OPEs and from 0.72 to 2213 ng/m3 for HFRs. The compounds with highest concentrations in both working areas were triphenyl phosphate (TPHP) and tris(2-chloroisopropyl) phosphate (TCIPP) for OPEs and decabromodiphenyl ether (BDE-209) for HFRs. Higher concentration levels were found in the CRT area compared to the grinding one, probably due to the lower ventilation and different types of e-waste being processed. OPEs were also detected in the solid e-waste from the facility, highlighting the need to evaluate pollutant levels in e-waste before proceeding to its re-use. Estimated daily intakes via inhalation during workday were calculated, as well as carcinogenic and non-carcinogenic health risks, these being 25 and 50 times lower than threshold risk values in the worst cases, respectively. However, this calculated risk only considers the workday exposure via inhalation, while other routes of exposure (e.g., ingestion, dermal) could bring these values closer to threshold values.

Noelin-1 is a secreted glycoprotein involved in generation of the neural crest.

The vertebrate neural crest arises at the border of the neural plate during early stages of nervous system development; however, little is known about the molecular mechanisms underlying neural crest formation. Here we identify a secreted protein, Noelin-1, which has the ability to prolong neural crest production. Noelin-1 messenger RNA is expressed in a graded pattern in the closing neural tube. It subsequently becomes restricted to the dorsal neural folds and migrating neural crest. Over expression of Noelin-1 using recombinant retroviruses causes an excess of neural crest emigration and extends the time that the neural tube is competent to generate as well as regenerate neural crest cells. These results support an important role for Noelin-1 in regulating the production of neural crest cells by the neural tube.

COVID-19 face masks: A new source of human and environmental exposure to organophosphate esters.

For the first time, organophosphate ester (OPE) content was studied in different types of surgical, self-filtering (KN95, FFP2, and FFP3) and reusable face masks used for COVID-19 prevention. OPEs were detected in all mask samples, although in highly variable amounts which ranged from 0.02 to a maximum of 27.7 µg/mask, with the highest mean concentrations obtained for KN95 masks (11.6 µg/mask) and the lowest for surgical masks (0.24 µg/mask). Twelve out of 16 tested analytes were detected, with TEP, TPHP, TNBP, TEHP and TClPP being the most common OPEs as well as present at the highest concentrations. The non-carcinogenic and carcinogenic risks of OPE inhalation were calculated as being always several orders of magnitude lower than threshold levels, indicating that the use of face masks is safe with regard to OPE contamination. However, given the wide range of OPEs observed in different masks, it can be concluded that some masks (e.g. reusable) are less OPE-contaminated than others (e.g. KN95). With regard to environmental pollution, the disposal of billions of face masks is adding to the already substantial levels of microplastics and associated toxic additives worldwide, an impact that is lessened by use of reusable masks, which also have the lowest economic cost per user. However, in situations of relatively high risk of viral inhalation, such as poorly ventilated indoor public spaces, we recommend the use of FFP2 masks.

Overview on the occurrence of microplastics in air and implications from the use of face masks during the COVID-19 pandemic.

Environmental pollution from microplastics (MPs) in air is a matter of growing concern because of human health implications. Airborne MPs can be directly and continuously inhaled in air environments. Especially high MPs contributions can be found in indoor air due to the erosion and breakage of consumer, domestic and construction products, although there is little information available on their sources and concentrations and the risks they might pose. This is in part due to the fact that sampling and analysis of airborne MPs is a complex and multistep procedure where techniques used are not yet standardized. In this study, we provide an overview on the presence of MPs in indoor air, potential health impacts, the available methods for their sampling and detection and implications from the use of face masks during the COVID-19 pandemic.

Organophosphate esters in airborne particles from subway stations.

For the first time, the concentrations of 19 organophosphate esters (OPEs) were measured in airborne fine particulate matter (PM2.5) from subway stations in Barcelona (Spain) to investigate their occurrence, contamination profiles and associated health risks. OPEs were detected in all PM2.5 samples with levels ranging between 1.59 and 202 ng/m3 (mean value of 39.9 ng/m3). Seventeen out of 19 tested analytes were detected, with TDClPP, TClPP and TCEP being those presenting the highest concentrations. OPE concentrations are not driven by the same factors that determine the ambient PM2.5 concentrations of other constituents in the subway. Newer stations presented higher OPE levels, probably due to the materials used in the design of the platforms, with greater use of modern plastic materials versus older stations with tiles and stones. Estimated daily intakes via airborne particles inhalation during the time expended in subway stations were calculated, as well as the carcinogenic and non-carcinogenic health risks (CR and non-CR), all being much lower than the threshold risk values. Thus, subway inhalation exposure when standing on the platform to OPE's per se is not considered to be dangerous for commuters.

Evaluation of the Semi-Continuous OCEC analyzer performance with the EUSAAR2 protocol.

This work evaluates the applicability of the reference protocol EUSAAR2 in the Semi-Continuous OCEC analyzer under two environments, an urban background site influenced by traffic emissions and a regional background site. The comparison of the 24-h averaged OC and EC measurements of the Semi-Continuous analyzer with the OC and EC concentrations determined offline in PM2.5 24 h filters yielded very good agreement for both denuded and undenuded samples. In the urban background site, the regression for EC yielded a slope of 0.93 and 1.04 (b = 0.07 and 0.05, R2 = 0.83 and 0.84), for denuded and undenuded samples respectively. The slopes of OC regressions were 0.99 (b = -0.18, R2 = 0.81) for the low volume and 0.93 (b = 0.12, R2 = 0.84) for the high volume samples. In the regional background site, the slopes of the EC regression with the denuded and undenuded samples was 0.91 and 1.02 correspondingly (b = 0 and - 0.03, R2 = 0.77 and 0.89). The regression of OC had slopes close to 1; 1.03 for the high volume and 0.95 for the low volume sampler (b = 0.08 and 0.26, R2 = 0.78 and 0.78). BC measurements obtained by an aethalometer and MAAP were in very good agreement with EC at both sampling sites. BC levels were consistently higher than EC (slope of the regression aethalometer BC vs EC slope a = 1.2, intercept b = 0.19, R2 = 0.79, for the urban background site and a = 1.9, b = -0.04, R2 = 0.94, for the regional site, slope MAAP BC vs EC a = 1.2, b = 0.06, R2 = 0.94, for the urban background site and 1.7, b = -0.03, R2 = 0.96, for the regional site). This confirms the need of using the site-specific mass absorption cross section (MAC) instead of the ones provided by manufacturers for the conversion of absorption units into BC mass concentration. BC data correlated very well with the optical EC obtained from the semi-continuous OCEC analyzer (a = 1.3, b = 0.16, R2 = 0.80 for the urban background site and a = 1.7, b = 0.009, R2 = 0.94 for the regional site, respectively). The comparison of OC concentrations by the Semi-Continuous Sunset analyzer with organic aerosol online measurements by ACSM showed strong correlations. The ratio OA/OC was 1.9 and 2.3 for the urban background and regional sites. The accumulation of refractory material on the filter, because of prolonged periods of sampling, caused a shift of the split point to the inert mode and changes on PC formation and evolution. Extreme dust outbreaks lead to the overestimation of OC due to the evolution of carbonate in the He mode. Generally, the Sunset Semi-Continuous OCEC analyzer with EUSAAR2 provided robust and consistent measurements with offline thermal-optical analysis.

Effect of ventilation strategies and air purifiers on the children's exposure to airborne particles and gaseous pollutants in school gyms.

Indoor school gyms are environments characterized by high concentrations of different airborne particulate and gaseous pollutants. In particular, like other naturally-ventilated school environments, in addition to indoor pollutants children can be exposed to sub-micron particles and gaseous pollutants emitted by outdoor sources and penetrating the building envelope; moreover, high concentrations of super-micron particles can be reached due to the resuspension phenomena related to the physical activity performed therein. The present paper aims to evaluate the effect of different ventilation methods (natural ventilation, manual airing) and the use of air purifiers in reducing the indoor concentrations of different airborne particles and gaseous pollutants in school gyms. To this end, an experimental campaign was performed in two naturally-ventilated school gyms in Barcelona (Spain) of different volumes and different distance to major urban roads. Indoor and outdoor measurements of particle number, black carbon and PM1-10 concentrations were performed as well as indoor measurements of CO2 and NO2 concentrations. The study revealed that the use of air purifiers with windows kept closed (natural ventilation) can lead to a significant reduction in terms of indoor-to-outdoor concentration ratios. In the smaller gym (air changes per hour of the purifiers, ACH, equal to 9.2 h-1) the I/O ratios were reduced by 93% and 95% in terms of particle number and PM1-10, respectively; whereas in the larger school gym (ACH = 1.7 h-1) the corresponding reductions were 70% and 84%. For manual airing scenarios, the effect of the air purifiers on outdoor-generated sub-micron particles is reduced; in particular, for low ACH values (i.e. ACH = 1.7 h-1), the reduction is quite negligible (6%).

Profiling transient daytime peaks in urban air pollutants: city centre traffic hotspot versus urban background concentrations.

Averaged annual and daily limit values imposed for the protection of human health from urban air pollutants fail to address the potential influence of variations in personal exposure during the day, even though asthma attacks, myocardial ischaemia, and other effects have been linked to highly transient rises in atmospheric contamination. There is, therefore, a general need for the wider availability of information on hourly variations in urban pollutant levels, as well as on spatial differences between urban background and localised contamination hotspots. We compare data from urban background and traffic hotspot monitoring stations over a 12-month period to demonstrate the hourly flux of air pollutants, notably NO(x), SO(2) and PM(10), and illustrate the effects of controlling influences, such as traffic movements and exotic dust intrusions. Our methodology focuses on daytime transient peaks, which occur when much of the urban population is awake and active, and when striking increases in pollutant concentrations are especially common at traffic hotspots. Greater emphasis on the daily reality of transient peaks in urban atmospheric pollutants offers a higher degree of spatial and temporal data resolution for use in epidemiological studies.

Neurodevelopmental outcome predictors of term newborns with neonatal seizures. / Predictores pronósticos de desarrollo neurológico en recién nacidos a término con crisis neonatales.

INTRODUCTION: The concrete burden of neonatal seizures in neurodevelopmental outcome of term newborns is still unknown in literature. The aim of this study was to describe prognostic predictors in neonatal seizures. SUBJECTS AND METHODS: Observational prospective study of term neonates with clinical seizures from a tertiary center (2009-2018). Adverse outcome was determined as death, global developmental delay, cerebral palsy or epilepsy. Perinatal characteristics, etiology, electrographic features, neuroimaging and antiepileptic treatment were analyzed in a logistic regression model. RESULTS: A total of 102 newborns were included (52 infants with normal outcome). Twelve fatalities were registered. In the survival group, 38 children had an adverse outcome (28 global developmental delay, 27 cerebral palsy, 21 epilepsy). From the prognostic variables identified in univariate analysis, perinatal complications, seizure onset in the first day of life, moderate to severe abnormal background activity, abnormal amplitude-integrated EEG pattern, and treatment response remained independently associated with adverse outcome after a logistic regression model. CONCLUSIONS: There is conflicting data about surrogate markers in neonatal seizures. Aside from confirming the predictive value of previously described variables, we observed that amplitude-integrated EEG monitoring is a forthcoming prognostic tool. Future approaches may include a wider use of amplitude-integrated EEG monitoring, being crucial for timely seizure identification and prompt treatment.

TITLE: Predictores pronósticos de desarrollo neurológico en recién nacidos a término con crisis neonatales.Introducción. El peso específico de las crisis neonatales en el pronóstico neurológico de recién nacidos a término no se conoce bien, por lo que el objetivo del estudio era describir predictores pronósticos en crisis neonatales. Sujetos y métodos. Estudio observacional prospectivo de recién nacidos a término con crisis clínicas en un centro terciario (2009-2018). Pronóstico adverso se definió como muerte, retraso global del desarrollo, parálisis cerebral o epilepsia. Se analizaron las características perinatales, la etiología, los hallazgos electroencefalográficos, la neuroimagen y los tratamientos antiepilépticos siguiendo un modelo de regresión logística. Resultados. Se incluyó a un total de 102 recién nacidos (52 de los cuales tenían desarrollo normal). Se registraron 12 fallecimientos. En el grupo de supervivientes, 38 niños tuvieron un pronóstico desfavorable (28 con retraso global del desarrollo, 27 con parálisis cerebral, 21 con epilepsia). De las variables pronósticas identificadas en el análisis univariante, las complicaciones perinatales, el inicio de las crisis en el primer día de vida, la actividad basal anormal moderada a grave, un patrón anormal en el electroencefalograma de amplitud integrada y la respuesta al tratamiento continuaron mostrándose como independientemente asociadas a pronóstico adverso después de aplicar un modelo de regresión logística. Conclusiones. Existen datos contradictorios sobre marcadores subrogados en crisis neonatales. Aparte de confirmar el valor predictivo de variables previamente descritas, se halló que la monitorización con electroencefalograma de amplitud integrada constituye una prometedora herramienta diagnóstica. En el futuro, se debería extender su utilización en el abordaje de estos pacientes, lo que sería de vital importancia para un diagnóstico y un tratamiento precoces.

Effectiveness of commercial face masks to reduce personal PM exposure.

Cycling and walking are promoted as means of transportation which can contribute to the reduction of traffic pollution in urban areas. However, cyclists and pedestrians may be exposed to high concentrations of air pollutants due to their proximity to vehicle emissions. Commercial face mask respirators are widely used, in both developing and developed countries, as an individual protective measure against particle pollution. However scientific data on the efficacy of face mask respirators in reducing airborne particle exposure is limited. In this study, a custom experimental set-up was developed in order to measure the effectiveness of nine different respirators under real environmental conditions in terms of particle mass concentration below 2.5 µm (PM2.5), particle number concentration (PNC), Lung Deposited Surface Area (LDSA) and Black Carbon concentration (BC). Face mask performances were assessed in a typical traffic affected urban background environment in the city of Barcelona under three different simulated breathing rates to investigate the influence of flow rate. Results showed a median face mask effectiveness for PM2.5 equal to 48% in a range of 14-96%, 19% in a range of 6%-61% for BC concentration, 19% in a range of 4%-63% for PNC and 22% in a range of 5%-65% for LDSA. For each pollutant under investigation, the best performance was found always with the same mask (N7) although it is not the most expensive (in a range of price of 1 to 44, its cost was 20 euros), which has a filter on the entire surface except for the 2 exhalation valves where air cannot enter but just exit and shows a good fit on the dummy head.

African dust and air quality over Spain: Is it only dust that matters?

The 2001-2016 contribution of African dust outbreaks to ambient regional background PM10 and PM2.5 levels over Spain, as well as changes induced in the PMx composition over NE Spain in 2009-2016, were investigated. A clear decrease in PMx dust contributions from the Canary Islands to N Iberia was found. A parallel increase in the PM2.5/PM10 ratio (30% in the Canary Islands to 57% in NW Iberia) was evidenced, probably due to size segregation and the larger relative contribution of the local PMx with increasing distance from Africa. PM1-10 and PM2.5-10 measured in Barcelona during African dust outbreaks (ADOs) were 43-46% higher compared to non-ADO days. The continental background contribution prevailed in terms of both PM1-10 and PM2.5-10 during ADO days (62 and 69%, respectively, and 31 and 27% for non-ADO days). The relative contributions of Al2O3/Fe2O3/CaO to PMx fraction showed that Al2O3 is a suitable tracer for African dust in our context; while CaO at the urban site is clearly affected by local resuspension, construction and road dust, and Fe2O3 by dust from vehicle brake discs. The results also provide evidence that PM increases during ADOs are caused not only by the mineral dust load, but by an increased accumulation of locally emitted or co-transported anthropogenic pollutants as compared with non-ADO days. Possible causes for this accumulation are discussed. We recommend that further epidemiological studies should explore independently the potential effects of mineral dust and the anthropogenic PM during ADOs, because, at least over SW Europe, not only mineral dust affects the air quality during African dust episodes.

Vertical and horizontal fall-off of black carbon and NO2 within urban blocks.

While exposure to traffic pollutants significantly decreases with distance from the curb, very dense urban architectures hamper such dispersion. Moreover, the building height reduces significantly the dispersion of pollutants. We have investigated the horizontal variability of Black Carbon (BC) and the vertical variability of NO2 and BC within the urban blocks. Increasing the distance from road BC concentrations decreased following an exponential curve reaching halving distances at 25 m (median), although with a wide variability among sites. Street canyons showed sharper fall-offs than open roads or roads next to a park. Urban background concentrations were achieved at 67 m distance on average, with higher distances found for more trafficked roads. Vertical fall-off of BC was less pronounced than the horizontal one since pollutants homogenize quickly vertically after rush traffic hours. Even shallower vertical fall-offs were found for NO2. For both pollutants, background concentrations were never reached within the building height. A street canyon effect was also found exacerbating concentrations at the lowest floors of the leeward side of the road. These inputs can be useful for assessing population exposure, air quality policies, urban planning and for models validation.

LAMA2 gene analysis in a cohort of 26 congenital muscular dystrophy patients.

Congenital muscular dystrophy type 1A (MDC1A) is caused by mutations in the LAMA2 gene encoding laminin-alpha2. We describe the molecular study of 26 patients with clinical presentation, magnetic resonance imaging and/or laminin-alpha2 expression in muscle, compatible with MDC1A. The combination of full genomic sequencing and complementary DNA analysis led to the particularly high mutation detection rate of 96% (50/52 disease alleles). Besides 22 undocumented polymorphisms, 18 different mutations were identified in the course of this work, 14 of which were novel. In particular, we describe the first fully characterized gross deletion in the LAMA2 gene, encompassing exon 56 (c.7750-1713_7899-2153del), detected in 31% of the patients. The only two missense mutations detected were found in heterozygosity with nonsense or truncating mutations in the two patients with the milder clinical presentation and a partial reduction in muscle laminin-alpha2. Our results corroborate the previous few genotype/phenotype correlations in MDC1A and illustrate the importance of screening for gross rearrangements in the LAMA2 gene, which may be underestimated in the literature.