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Air pollution is a suspected developmental neurotoxicant. Many schools are located in close proximity to busy roads, and traffic air pollution peaks when children are at school. We aimed to assess whether exposure of children in primary school to traffic-related air pollutants is associated with impaired cognitive development. We conducted a prospective study of children (n = 2,715, aged 7 to 10 y) from 39 schools in Barcelona (Catalonia, Spain) exposed to high and low traffic-related air pollution, paired by school socioeconomic index; children were tested four times (i.e., to assess the 12-mo developmental trajectories) via computerized tests (n = 10,112). Chronic traffic air pollution (elemental carbon [EC], nitrogen dioxide [NO2], and ultrafine particle number [UFP; 10-700 nm]) was measured twice during 1-wk campaigns both in the courtyard (outdoor) and inside the classroom (indoor) simultaneously in each school pair. Cognitive development was assessed with the n-back and the attentional network tests, in particular, working memory (two-back detectability), superior working memory (three-back detectability), and inattentiveness (hit reaction time standard error). Linear mixed effects models were adjusted for age, sex, maternal education, socioeconomic status, and air pollution exposure at home. Children from highly polluted schools had a smaller growth in cognitive development than children from the paired lowly polluted schools, both in crude and adjusted models (e.g., 7.4% [95% CI 5.6%-8.8%] versus 11.5% [95% CI 8.9%-12.5%] improvement in working memory, p = 0.0024). Cogently, children attending schools with higher levels of EC, NO2, and UFP both indoors and outdoors experienced substantially smaller growth in all the cognitive measurements; for example, a change from the first to the fourth quartile in indoor EC reduced the gain in working memory by 13.0% (95% CI 4.2%-23.1%). Residual confounding for social class could not be discarded completely; however, the associations remained in stratified analyses (e.g., for type of school or high-/low-polluted area) and after additional adjustments (e.g., for commuting, educational quality, or smoking at home), contradicting a potential residual confounding explanation. Children attending schools with higher traffic-related air pollution had a smaller improvement in cognitive development.
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... Exposure to traffic related air pollution may lead to brain damage through neuroinflammation and oxidative stress pathways, or through neurotoxicity (Block et al., 2012). Areas of prefrontal cortex that support self-regulation may be particularly impacted by these neurobiological mechanisms (Calderón-Garcidueñas et al., 2008;Peterson et al., 2015), and air pollution has been shown to have direct effects on self-regulatory skills in childhood (Perera et al., 2012;Chiu et al., 2013;Sunyer et al., 2015;Harris et al., 2016). Living in high traffic density areas has been associated with teacher rated executive function skills in mid childhood (Harris et al., 2016). ...
... Living in high traffic density areas has been associated with teacher rated executive function skills in mid childhood (Harris et al., 2016). Exposure to traffic related air pollution has been associated with poorer inhibitory control (Chiu et al., 2013), slower growth in attention and working memory over a 12 month period (Sunyer et al., 2015), and higher attention problems (Perera et al., 2012). ...
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We present a conceptual model of the ways in which built and social environments shape the development of self-regulation in early childhood. Importantly, in centering children of color growing up in historically disinvested neighborhoods, we first describe how systemic structures of racism and social stratification have shaped neighborhood built and social environment features. We then present evidence linking these neighborhood features to children’s development of self-regulation. Furthermore, we take a multilevel approach to examining three potential pathways linking neighborhood contexts to self-regulation: school environment and resources, home environment and resources, and child health behaviors. Finally, we consider how racial-ethnic-cultural strengths and multilevel interventions have the potential to buffer children’s development of self-regulation in disinvested neighborhood contexts. Advancing multilevel approaches to understand the development of self-regulation among children of color living in historically disinvested neighborhoods is an important step in efforts to promote equity in health and education.
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An active soil filter system was newly designed and evaluated to obtain a higher removal efficiency of fine particulate matter (PM) for indoor air purification in schools. Unlike passive air purification systems that remove PM using only plant leaves, air purification can be maximized by filtering polluted indoor air directly between the soil particles supporting the plant. The novel system is composed of a composite soil layer and a suction blower that forces outside air into the soil layer. It was found that the air purification performance was improved as the inflow air velocity upstream of the soil is decreased and the soil stacking height increased. The lower the soil moisture, the better the air purification performance. Considering both the classroom environment and the system’s energy consumption, it is recommended that the soil stacking height is 150 mm, the soil inflow air velocity is 2 cm/s, and the relative humidity is 35%. Under these conditions, the air purification efficiency for PM2.5 is 41.5%. The indoor air purification system using the soil filter system, along with the currently used plant leaves medium, is expected to improve the indoor air quality in public facilities, such as school classrooms.
... Exposure of primary school children to traffic generated air pollutants can affect their cognitive development and may result in impaired learning skills. For example, Sunyer et al. (2015) reported that children from highly polluted schools had a smaller growth in cognitive development compared with the children of schools with lower level of air pollutants. UNICEF (2019) have found that children experienced 15 % of their daily black carbon (BC) exposure while travelling to school, and 44 % during their time in school. ...
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... The 1-back load is the simplest one and, in this study, we chose to discard its results due to a ceiling effect, i.e., a perfect score was achieved by most of the children. The 2-back load can be an indicator of general mental abilities, while the highest load, the 3-back, can be an indicator of superior mental functions [33]. N-back task is used to determine detectability (d ) for each load, which was calculated as follows: d = z(hit rate) − z(false alarm rate). ...
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Citation: Compañ-Gabucio, L.M.; Torres-Collado, L.; Garcia-de la Hera, M.; Fernández-Somoano, A.; Tardón, A.; Julvez, J.; Sunyer, J.; Rebagliato, M.; Murcia, M.; Ibarluzea, J.; et al. Association between the Use of Folic Acid Supplements during Pregnancy and Children's Cognitive Function at 7-9 Years of Age in the INMA Cohort Study. Int.
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