Raphael E. Arku
Harvard University
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Featured researches published by Raphael E. Arku.
Environmental Science & Technology | 2010
Kathie L. Dionisio; Raphael E. Arku; Allison F. Hughes; Jose Vallarino; Heather Carmichael; John D. Spengler; Samuel Agyei-Mensah; Majid Ezzati
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 PM(2.5) ranged from 39 to 53 microg/m(3) at roadside sites and 30 to 70 microg/m(3) at residential sites; mean annual PM(10) ranged from 80 to 108 microg/m(3) at roadside sites and 57 to 106 microg/m(3) 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.
Environmental Health Perspectives | 2010
Kathie L. Dionisio; Michael S. Rooney; Raphael E. Arku; Ari B. Friedman; Allison F. Hughes; Jose Vallarino; Samuel Agyei-Mensah; John D. Spengler; Majid Ezzati
Background Sources of air pollution in developing country cities include transportation and industrial pollution, biomass and coal fuel use, and resuspended dust from unpaved roads. Objectives Our goal was to understand within-neighborhood spatial variability of particulate matter (PM) in communities of varying socioeconomic status (SES) in Accra, Ghana, and to quantify the effects of nearby sources on local PM concentration. Methods 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. Results 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 density. 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. Conclusions 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.
Proceedings of the National Academy of Sciences of the United States of America | 2011
Zheng Zhou; Kathie L. Dionisio; Raphael E. Arku; Audrey Quaye; Allison F. Hughes; Jose Vallarino; John D. Spengler; Allan G. Hill; Samuel Agyei-Mensah; Majid Ezzati
Many urban households in developing countries use biomass fuels for cooking. The proportion of household biomass use varies among neighborhoods, and is generally higher in low socioeconomic status (SES) communities. Little is known of how household air pollution varies by SES and how it is affected by biomass fuels and traffic sources in developing country cities. In four neighborhoods in Accra, Ghana, we collected and analyzed geo-referenced data on household and community particulate matter (PM) pollution, SES, fuel use for domestic and small-commercial cooking, housing characteristics, and distance to major roads. Cooking area PM was lowest in the high-SES neighborhood, with geometric means of 25 (95% confidence interval, 21–29) and 28 (23–33) μg/m3 for fine and coarse PM (PM2.5 and PM2.5–10), respectively; it was highest in two low-SES slums, with geometric means reaching 71 (62–80) and 131 (114–150) μg/m3 for fine and coarse PM. After adjustment for other factors, living in a community where all households use biomass fuels would be associated with 1.5- to 2.7-times PM levels in models with and without adjustment for ambient PM. Community biomass use had a stronger association with household PM than households own fuel choice in crude and adjusted estimates. Lack of regular physical access to clean fuels is an obstacle to fuel switching in low-income neighborhoods and should be addressed through equitable energy infrastructure.
Science of The Total Environment | 2012
Michael S. Rooney; Raphael E. Arku; Kathie L. Dionisio; Christopher J. Paciorek; Ari B. Friedman; Heather Carmichael; Zheng Zhou; Allison F. Hughes; Jose Vallarino; Samuel Agyei-Mensah; John D. Spengler; Majid Ezzati
Sources of air pollution in developing country cities include transportation and industrial pollution, biomass fuel use, and re-suspended dust from unpaved roads. We examined the spatial patterns of particulate matter (PM) and its sources in four neighborhoods of varying socioeconomic status (SES) in Accra. PM data were from 1 week of morning and afternoon mobile and stationary air pollution measurements in each of the study neighborhoods. PM(2.5) and PM(10) were measured continuously, with matched GPS coordinates. Data on biomass fuel use were from the Ghana 2000 population and housing census and from a census of wood and charcoal stoves along the mobile monitoring paths. We analyzed the associations of PM with sources using a mixed-effects regression model accounting for temporal and spatial autocorrelation. After adjusting for other factors, the density of wood stoves, fish smoking, and trash burning along the mobile monitoring path as well as road capacity and surface were associated with higher PM(2.5). Road capacity and road surface variables were also associated with PM(10), but the association with biomass sources was weak or absent. While wood stoves and fish smoking were significant sources of air pollution, addressing them would require financial and physical access to alternative fuels for low-income households and communities.
Indoor Air | 2015
Raphael E. Arku; Gary Adamkiewicz; Jose Vallarino; John D. Spengler; Douglas E. Levy
The risk of tobacco smoking and second-hand smoke (SHS) exposure combined are the leading contributors to disease burden in high-income countries. Recent studies and policies are focusing on reducing exposure to SHS in multiunit housing (MUH), especially public housing. We examined seasonal patterns of SHS levels within indoor common areas located on Boston Housing Authority (BHA) properties. We measured weekly integrated and continuous fine particulate matter (PM2.5) and passive airborne nicotine in six buildings of varying building and occupant characteristics in summer 2012 and winter 2013. The average weekly indoor PM2.5 concentration across all six developments was 9.2 μg/m3, higher during winter monitoring period (10.3 μg/m3) compared with summer (8.0 μg/m3). Airborne nicotine concentrations ranged from no detection to about 5000 ng/m3 (mean 311 ng/m3). Nicotine levels were significantly higher in the winter compared with summer (620 vs. 85 ng/m3; 95% CI: 72-998). Smoking-related exposures within Boston public housing vary by season, building types, and resident smoking policy. Our results represent exposure disparities that may contribute to health disparities in low-income communities and highlight the potential importance of efforts to mitigate SHS exposures during winter when outdoor-indoor exchange rates are low and smokers may tend to stay indoors. Our findings support the use of smoke-free policy as an effective tool to eliminate SHS exposure and protect non-smokers, especially residents of MUH.
Environmental Science & Technology | 2014
Zheng Zhou; Kathie L. Dionisio; Thiago G. Veríssimo; Américo Sansigolo Kerr; Brent A. Coull; Stephen R. C. Howie; Raphael E. Arku; Petros Koutrakis; John D. Spengler; Kimberly Fornace; Allison F. Hughes; Jose Vallarino; Samuel Agyei-Mensah; Majid Ezzati
Household air pollution in sub-Saharan Africa and other developing regions is an important cause of disease burden. Little is known about the chemical composition and sources of household air pollution in sub-Saharan Africa, and how they differ between rural and urban homes. We analyzed the chemical composition and sources of fine particles (PM2.5) in household cooking areas of multiple neighborhoods in Accra, Ghana, and in peri-urban (Banjul) and rural (Basse) areas in The Gambia. In Accra, biomass burning accounted for 39-62% of total PM2.5 mass in the cooking area in different neighborhoods; the absolute contributions were 10-45 μg/m(3). Road dust and vehicle emissions comprised 12-33% of PM2.5 mass. Solid waste burning was also a significant contributor to household PM2.5 in a low-income neighborhood but not for those living in better-off areas. In Banjul and Basse, biomass burning was the single dominant source of cooking-area PM2.5, accounting for 74-87% of its total mass; the relative and absolute contributions of biomass smoke to PM2.5 mass were larger in households that used firewood than in those using charcoal, reaching as high as 463 μg/m(3) in Basse homes that used firewood for cooking. Our findings demonstrate the need for policies that enhance access to cleaner fuels in both rural and urban areas, and for controlling traffic emissions in cities in sub-Saharan Africa.
Environmental Research Letters | 2013
Zheng Zhou; Kathie L. Dionisio; Thiago G. Veríssimo; Américo Sansigolo Kerr; Brent A. Coull; Raphael E. Arku; Petros Koutrakis; John D. Spengler; Allison F. Hughes; Jose Vallarino; Samuel Agyei-Mensah; Majid Ezzati
The highest levels of air pollution in the world now occur in developing country cities, where air pollution sources differ from high-income countries. We analyzed particulate matter (PM) chemical composition and estimated the contributions of various sources to particle pollution in poor and affluent neighborhoods of Accra, Ghana. Elements from earth?s crust were most abundant during the seasonal Harmattan period between late December and late January when Saharan dust is carried to coastal West Africa. During Harmattan, crustal particles accounted for 55??g?m?3 (37%) of fine particle (PM2.5) mass and 128??g?m?3 (42%) of PM10 mass. Outside Harmattan, biomass combustion, which was associated with higher black carbon, potassium, and sulfur, accounted for between 10.6 and 21.3??g?m?3 of fine particle mass in different neighborhoods, with its contribution largest in the poorest neighborhood. Other sources were sea salt, vehicle emissions, tire and brake wear, road dust, and solid waste burning. Reducing air pollution in African cities requires policies related to energy, transportation and urban planning, and forestry and agriculture, with explicit attention to impacts of each strategy in poor communities. Such cross-sectoral integration requires emphasis on urban environment and urban poverty in the post-2015 Development Agenda.
Science of The Total Environment | 2016
Piers MacNaughton; Gary Adamkiewicz; Raphael E. Arku; Jose Vallarino; Douglas E. Levy
BACKGROUND Smoke-free housing policies have the potential to reduce secondhand smoke (SHS) exposures for residents of multi-unit housing. Since common areas represent a pathway of SHS movement between units, smoke-free policies would be expected to reduce SHS in these microenvironments. METHODS Week-long air nicotine and PM2.5 (particulate matter below 2.5μm in aerodynamic diameter) samples were collected in the common areas of 10 Boston Housing Authority (BHA) and 6 Cambridge Housing Authority (CHA) buildings from January 2012 to October 2013. We also measured one outdoor PM level at each study building. Samples from BHA included pre and post- smoke-free policy measurements. Each development was visited three times over the course of the study period. The effect of the smoking ban on indoor PM2.5 was examined using generalized mixed effect models to accommodate repeated measurement at each site. Changes in nicotine concentrations were modeled using quantile mixed regression to reduce the impact of outliers. RESULTS After controlling for season, site, and background PM2.5 concentrations, PM2.5 levels were 4.05μg/m(3) (p-value=0.09) lower in BHA after the smoke-free policy was implemented in the summer of 2012, compared with CHA developments, which had no smoking policy in place. Similarly, nicotine levels decreased by 57% (p-value=0.08) in Boston relative to Cambridge after the ban. CONCLUSIONS Our findings support the use of smoke-free policies as an effective tool to reduce SHS exposure and protect non-smokers, especially residents of multi-unit housing.
PLOS Medicine | 2016
Raphael E. Arku; James Bennett; Marcia C. Castro; Kofi Agyeman-Duah; Samilia E. Mintah; James H. Ware; Philomena Nyarko; John D. Spengler; Samuel Agyei-Mensah; Majid Ezzati
Background Under-five mortality is declining in Ghana and many other countries. Very few studies have measured under-five mortality—and its social and environmental risk factors—at fine spatial resolutions, which is relevant for policy purposes. Our aim was to estimate under-five mortality and its social and environmental risk factors at the district level in Ghana. Methods and Findings We used 10% random samples of Ghana’s 2000 and 2010 National Population and Housing Censuses. We applied indirect demographic methods and a Bayesian spatial model to the information on total number of children ever born and children surviving to estimate under-five mortality (probability of dying by 5 y of age, 5q0) for each of Ghana’s 110 districts. We also used the census data to estimate the distributions of households or persons in each district in terms of fuel used for cooking, sanitation facility, drinking water source, and parental education. Median district 5q0 declined from 99 deaths per 1,000 live births in 2000 to 70 in 2010. The decline ranged from <5% in some northern districts, where 5q0 had been higher in 2000, to >40% in southern districts, where it had been lower in 2000, exacerbating existing inequalities. Primary education increased in men and women, and more households had access to improved water and sanitation and cleaner cooking fuels. Higher use of liquefied petroleum gas for cooking was associated with lower 5q0 in multivariate analysis. Conclusions Under-five mortality has declined in all of Ghana’s districts, but the cross-district inequality in mortality has increased. There is a need for additional data, including on healthcare, and additional environmental and socioeconomic measurements, to understand the reasons for the variations in mortality levels and trends.
Journal of Exposure Science and Environmental Epidemiology | 2015
Raphael E. Arku; Kathie L. Dionisio; Allison F. Hughes; Jose Vallarino; John D. Spengler; Marcia C. Castro; Samuel Agyei-Mensah; Majid Ezzati
Air pollution exposure and places where the exposures occur may differ in cities in the developing world compared with high-income countries. Our aim was to measure personal fine particulate matter (PM2.5) exposure of students in neighborhoods of varying socioeconomic status in Accra, Ghana, and to quantify the main predictors of exposure. We measured 24-hour PM2.5 exposure of 56 students from eight schools in four neighborhoods. PM2.5 was measured both gravimetrically and continuously, with time-matched global positioning system coordinates. We collected data on determinants of exposure, such as distances of homes and schools from main roads and fuel used for cooking at their home or in the area of residence/school. The association of PM2.5 exposure with sources was estimated using linear mixed-effects models. Personal PM2.5 exposures ranged from less than 10 μg/m3 to more than 150 μg/m3 (mean 56 μg/m3). Girls had higher exposure than boys (67 vs 44 μg/m3; P-value=0.001). Exposure was inversely associated with distance of home or school to main roads, but the associations were not statistically significant in the multivariate model. Use of biomass fuels in the area where the school was located was also associated with higher exposure, as was household’s own biomass use. Paved schoolyard surface was associated with lower exposure. School locations in relation to major roads, materials of school ground surfaces, and biomass use in the area around schools may be important determinants of air pollution exposure.