Improving air filter efficiency as a strategy to reduce children’s exposure to traffic related air pollutants in energy-efficient classrooms

This study was organised to quantify the effect of upgrading the filter efficiency in balance ventilation systems on indoor exposure to traffic-related air pollution, in 4 primary school classrooms. The standard air filters (EU F7) were compared with more efficient EU F9, and with F7+active carbon filters. Particulate matter (PM), ultrafine particles (UFP), black carbon (BC), PM2.5, organic/elemental carbon in PM2.5 (EC/OC), and NO2 were quantified, air tightness and air supply rates were assessed and pupils’ indoor comfort was surveyed. Analysis of indoor air as function of outdoor air and filter type indicated a significant but small reduction of indoor levels when upgrading the filter, except for PM10, TSP and UFP. The indoor comfort survey indicated a small but significant and positive effect as well

The future of passive techniques in air change rate measurement

Ventilation is critical in interpreting indoor air quality (IAQ), but only few IAQ assessments report ventilation rates; even when they do, the measurement method is often not fully de-scribed. Most ventilation assessments use a tracer gas test (TGT) approach to measure total air change rate, which consists in marking the indoor air with an easily identifiable gas (tracer) and then inferring the air exchange rate by monitoring the tracer’s injection rate and concen-tration (Persily, 2016). For this monitoring, two sampling options can be used: active sam-plers, costly and complex, or passive samplers (which work by absorption/adsorption without electricity use), overall more advantageous: cheaper, smaller, lighter, simpler and silent. Af-fordable passive samplers are commercialized by a range of companies and are already widely used in IAQ studies to analyse the presence of several gaseous pollutants (Stranger et al., 2008). However, currently employed TGTs in IAQ assessments are either active or not con-ceived to be executed together with common IAQ analysis, providing ventilation rates in a different time-scale than the pollutant concentrations. Thus, this paper proposes a new ap-proach for the TGT method, using as tracer a substance that can be co-captured and co-analysed using commercial passive samplers commonly used in IAQ studies

Proposing a new tracer gas for future field applications of passive tracer gas tests for air change rate measurement

This paper describes the ongoing development of a new adaptation of the traditional tracer gas test (TGT) used for total air change rates (ACH) measurement. This adapted TGT, based on constant tracer injection, is intended for use in large-scale IAQ assessments and employs an alternative tracer gas that is more adequate than the currently employed SF6 and perfluorocarbons, and that can be co-captured and coanalysed with commonly assessed VOCs by commercial passive IAQ-sampling. Via literature study and lab experiments, decane-D22 was found to be a suitable tracer substance. A passive source of decane- D22 was developed and optimized in lab, providing stable and repeatable emission rates under standard temperature, while unaffected by varying RH and ACH. The effect of the liquid solvent level over the source emission rate was only barely noticeable, but a range of adequate solvent level is suggested nevertheless. The selected tracer was also shown not to adhere/absorb significantly to surfaces. Additionally, a consistent exponential curve was derived for determining the source emission rate from the room temperature. Field applications of this new TGT adaptation are ongoing and will be published elsewhere shortly.publishedVersio

conseil supérieur de la santé - Aspects environnementaux et durables de la pandémie de Covid-19.

La pandémie actuelle de COVID-19 (maladie à coronavirus 2019) est une expérience unique pour les générations actuelles. Au cours des premiers mois de l'épidémie mondiale, la plupart des scientifiques se sont intéressés aux aspects médicaux, en particulier à l'épidémiologie et à la virologie. Peu à peu, l'impact réciproque de la qualité de l'environnement sur la transmission du virus et des effets du confinement pour contrôler la transmission ont été documentés. Il apparaît clairement que la maladie et la manière dont les pays limitent sa transmission ont également des aspects environnementaux et des répercussions sur la santé et la durabilité. Le développement durable comprend des aspects liés à l'économie, à la société et à l'environnement. Le confinement, qui a été mis en place dans de nombreux pays pour limiter les contacts sociaux et, par conséquent, la propagation de la maladie, a eu un impact majeur sur l'économie, du niveau local au niveau mondial : dans de nombreux secteurs, des gens ont perdu leur emploi, les entreprises ont été confrontées à des problèmes de rentabilité décroissante et les pays ne savent pas encore comment faire face aux cratères financiers dans leur budget qu'ont creusé les mesures d'atténuation en cours. En fait, une étude systématique des 3 R (Raisons-Réponses-Recommandations) a rapporté des effets principalement négatifs sur 13 des 17 objectifs de développement durable (ODD) de l’Organisation des Nations unies (ONU). La distanciation physique, considérée comme le moyen le plus efficace pour une population de contrôler la propagation du virus SARS-CoV-2 (coronavirus 2 du syndrome respiratoire aigu sévère), provoque des problèmes psychosociaux chez les personnes âgées, les jeunes et d'autres groupes de la société. Il est associé à une augmentation des problèmes de sécurité et perturbe profondément le tourisme et les migrations. Sur le plan environnemental, le nombre et la qualité des données sur les aspects affectés soit directement par le COVID-19, soit indirectement par les mesures visant à limiter l'incidence de l'infection, augmentent rapidement. Dans la littérature récente, on peut noter les éléments suivants.....Ces données appellent à inclure une approche interdisciplinaire et d'écologie humaine dans la COVID-19 et les stratégies de prévention et de gestion de la propagation de la pandémie.Avis n°961

A Snapshot of CNVs in the Pig Genome

Recent studies of mammalian genomes have uncovered the extent of copy number variation (CNV) that contributes to phenotypic diversity, including health and disease status. Here we report a first account of CNVs in the pig genome covering part of the chromosomes 4, 7, 14, and 17 already sequenced and assembled. A custom tiling oligonucleotide array was used with a median probe spacing of 409 bp for screening 12 unrelated Duroc boars that are founders of a large family material. After a strict CNV calling pipeline, 37 copy number variable regions (CNVRs) across all four chromosomes were identified, with five CNVRs overlapping segmental duplications, three overlapping pig unigenes and one overlapping a RefSeq pig mRNA. This CNV snapshot analysis is the first of its kind in the porcine genome and constitutes the basis for a better understanding of porcine phenotypes and genotypes with the prospect of identifying important economic traits

Genomic Relationships, Novel Loci, and Pleiotropic Mechanisms across Eight Psychiatric Disorders

Genetic influences on psychiatric disorders transcend diagnostic boundaries, suggesting substantial pleiotropy of contributing loci. However, the nature and mechanisms of these pleiotropic effects remain unclear. We performed analyses of 232,964 cases and 494,162 controls from genome-wide studies of anorexia nervosa, attention-deficit/hyper-activity disorder, autism spectrum disorder, bipolar disorder, major depression, obsessive-compulsive disorder, schizophrenia, and Tourette syndrome. Genetic correlation analyses revealed a meaningful structure within the eight disorders, identifying three groups of inter-related disorders. Meta-analysis across these eight disorders detected 109 loci associated with at least two psychiatric disorders, including 23 loci with pleiotropic effects on four or more disorders and 11 loci with antagonistic effects on multiple disorders. The pleiotropic loci are located within genes that show heightened expression in the brain throughout the lifespan, beginning prenatally in the second trimester, and play prominent roles in neurodevelopmental processes. These findings have important implications for psychiatric nosology, drug development, and risk prediction.Peer reviewe