Impact of fine particulate matter and toxic gases on the health of school children in Dhaka, Bangladesh

Background . Air pollution exposure has a detrimental effect on children who spend more than 17% of their weekdays inside a school building. The purpose of this study is to look into the effects of particulate matter (PM) and toxic gases on health of the school children. Between April and November 2018, samples were collected in real time from ten different schools (both indoor and outdoor) over four hours on two consecutive days at each school. During the first two hours, when students were present in the classroom, measurements were conducted inside the classroom. After that the measurements were conducted outside the classroom but within the school premises - when students were playing on the playground or eating breakfast outside of classroom. Method . To evaluate the impact of air pollution, 250 students (on average 20 students from each school) aged from 9 to 12 were selected from ten schools. Automatic monitors (AEROCET 531S, USA) were employed to measure PM _1.0 , PM _2.5, and PM _10 concentrations. NO _2 , TVOC, and CO _2 concentrations were measured using an AEROQUAL (500S, New Zealand), and the respiratory rate is measured by BSMI Peak Flow Meter (Made: BSMI, Origin: China). Monitors were placed at about 2.0 meters above the floor at breathing height and no student wore the sensors. The ANOVA test was conducted to see the statistical significance between air quality parameters and peak flow meter readings. Results . The mean ± standard deviation of PM _1.0 , PM _2.5, and PM _10 concentrations were 19.1 ± 3.6, 34.2 ± 10.1, and 131.3 ± 58.6 μ gm ^−3 , respectively. PM _2.5 and PM _10 concentrations exceeded WHO standards (15 and 45 μ gm ^−3 of 24 h) by 2.3 and 2.9 times. The highest concentrations of toxic gases were found on school campuses where vehicle densities (measured manually) were high. The mean Hazard Quotient (HQ) for PM _10 (2.5 ± 2.2 indoor; 3.6 ± 2.6 outdoor) and PM _2.5 (1.8 ± 0.8 indoor; 1.9 ± 1.0 outdoor) among all participating students was >1 indicating an unacceptable risk for human health. Lung function associated with the PEF value has a negative correlation with PM _1.0 and PM _2.5 concentrations in most cases. Conclusions . The findings of this study are useful in gaining a general understanding of the school environment in Dhaka. It aimed to understand how children were personally exposed in school and to develop effective control strategies to mitigate negative effects

Large global variations in measured airborne metal concentrations driven by anthropogenic sources

Please read abstract in the article.All data are freely available as a public good at http://www.spartan-network.org.Bloomberg Philanthropies through the Health Effects Institute, by the ClimateWorks Foundation, the Natural Sciences and Engineering Research Council (NSERC) of Canada, the Indo-US Science and Technology Forum (IUSSTF), the Environmental Health Fund (Israel), the Israel Science Foundation, Ministry of Research, Technology & Higher Education, under World Class University (WCU) managed by Bandung Institute of Technology (ITB), the Singapore National Research Foundation (NRF) through the Singapore-MIT Alliance for Research and Technology (SMART), Center for Environmental Sensing and Modeling, NASA Applied Science Program and the Jet Propulsion Laboratory.www.nature.com/scientificreportsam2021Geography, Geoinformatics and Meteorolog

Large global variations in measured airborne metal concentrations driven by anthropogenic sources

International audienceGlobally consistent measurements of airborne metal concentrations in fine particulate matter (PM2.5) are important for understanding potential health impacts, prioritizing air pollution mitigation strategies, and enabling global chemical transport model development. PM2.5 filter samples (N ~ 800 from 19 locations) collected from a globally distributed surface particulate matter sampling network (SPARTAN) between January 2013 and April 2019 were analyzed for particulate mass and trace metals content. Metal concentrations exhibited pronounced spatial variation, primarily driven by anthropogenic activities. PM2.5 levels of lead, arsenic, chromium, and zinc were significantly enriched at some locations by factors of 100-3000 compared to crustal concentrations. Levels of metals in PM2.5 and PM10 exceeded health guidelines at multiple sites. For example, Dhaka and Kanpur sites exceeded the US National Ambient Air 3-month Quality Standard for lead (150 ng m-3). Kanpur, Hanoi, Beijing and Dhaka sites had annual mean arsenic concentrations that approached or exceeded the World Health Organization's risk level for arsenic (6.6 ng m-3). The high concentrations of several potentially harmful metals in densely populated cites worldwide motivates expanded measurements and analyses