Browsing by Author "Spengler, J. D."
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Item particle Pollution in Accra Neighbourhoods: Spatial, Temporal, and Socioeconomic Patterns(Environmental Science and Technology, 2010) Dionisio, K. L.; Arku, R. E.; Hughes, A. F.; Vallarino, J.; Carmichael, H.; Friedman, A. B.; Agyei-Mensah, S.; Spengler, J. D.; Ezzati, M.This study examined the spatial, socioeconomic status (SES), and temporal patterns of ambient air pollution in Accra, Ghana. Over 22 months, integrated and continuous rooftop particulate matter (PM) monitors were placed at a total of 11 residential or roadside monitoring sites in four neighborhoods of varying SES and biomass fuel use. PM concentrations were highest in late December and January, due to dust blown from the Sahara. Excluding this period, annual PM2.5 ranged from 39 to 53 μg/m3 at roadside sites and 30 to 70 μg/m3 at residential sites; mean annual PM10 ranged from 80 to 108 μg/m3 at roadside sites and 57 to 106 μg/m3 at residential sites. The low-income and densely populated neighborhood of Jamestown/Ushertown had the single highest residential PM concentration. There was less difference across traffic sites. Daily PM increased at all sites at daybreak, followed by a mid-day peak at some sites, and a more spread-out evening peak at all sites. Average carbon monoxide concentrations at different sites and seasons ranged from 7 to 55 ppm, and were generally lower at residential sites than at traffic sites. The results show that PM in these four neighborhoods is substantially higher than the WHO Air Quality Guidelines and in some cases even higher than the WHO Interim Target 1, with the highest pollution in the poorest neighborhood.Item Within Neighborhood Patterns and Sources of particle Pollution: Mobile Monitoring and GIS Analysis in Four Accra Communities(Environmental Health Perspectives, 2010) Dionisio, K. L.; Rooney, M. S.; Arku, R. E.; Friedman, A. B.; Paciorek, C.; Hughes, A. F.; Vallarino, J.; Carmichael, H.; Agyei-Mensah, S.; Spengler, J. D.; Ezzati, M.Sources of air pollution in developing country cities include transportation and industrial pollution, biomass and coal fuel use, and resuspended dust from unpaved roads. Our goal was to understand within-neighborhood spatial variability of particulate mat¬ter (PM) in communities of varying socioeconomic status (SES) in Accra, Ghana, and to quantify the effects of nearby sources on local PM concentration.We conducted 1 week of morning and afternoon mobile and stationary air pollution measurements in four study neighborhoods. PM with aerodynamic diameters ≤ 2.5 μm (PM2.5) and ≤ 10 μm (PM10) was measured continuously, with matched global positioning system coordinates; detailed data on local sources were collected at periodic stops. The effects of nearby sources on local PM were estimated using linear mixed-effects models. In our measurement campaign, the geometric means of PM2.5 and PM10 along the mobile monitoring path were 21 and 49 μg/m3, respectively, in the neighborhood with highest SES and 39 and 96 μg/m3, respectively, in the neighborhood with lowest SES and highest population den¬sity. PM2.5 and PM10 were as high as 200 and 400 μg/m3, respectively, in some segments of the path. After adjusting for other factors, the factors that had the largest effects on local PM pollution were nearby wood and charcoal stoves, congested and heavy traffic, loose dirt road surface, and trash burning. Biomass fuels, transportation, and unpaved roads may be important determinants of local PM variation in Accra neighborhoods. If confirmed by additional or supporting data, the results demonstrate the need for effective and equitable interventions and policies that reduce the impacts of traffic and biomass pollution.