Personal particulate matter exposures and locations of students in four neighborhoods in Accra, Ghana

Abstract

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/m(3) to more than 150 μg/m(3) (mean 56 μg/m(3)). Girls had higher exposure than boys (67 vs 44 μg/m(3); 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.

When, Where, and What? Characterizing Personal PM2.5 Exposure in Periurban India by Integrating GPS, Wearable Camera, and Ambient and Personal Monitoring Data

“…This difference was explained by participants' activities during the day, which resulted in higher levels of exposure compared to background PM 2.5 . Similar results have been found in lowmiddle income countries comparing personal and ambient PM 2.5 11,38 . Comparable levels of personal and ambient PM 2.5 at night were likely due to well ventilated buildings and the lack of indoor sources at night.…”

“…As a comparison, a study that measured 62 non-smoking pregnant women in Canada in 1-3 48h monitoring sessions42 developed a prediction model for personal exposure to fine particulate matter with a selfreported diary of activities and locations and ambient monitoring which explained a 29% of the exposure variability. In another study measuring 56 students from eight schools in Ghana, models predicting 24h personal exposure to PM 2.5 using fixed household indicators as well as ambient concentrations, meteorology, and GPS-derived distance from several sources during the day, achieved a conditional R 2 of 0.6211 . Finally, a study on 200 women cooking with biomass fuels in Sichuan, China, explained 52% of the variability of 48h PM 2.5 exposure in…”

Personal exposure to PM<sub>2.5</sub> emitted from typical anthropogenic sources in southern West Africa: chemical characteristics and associated health risks

“…It was 4.7 times the daily average PE PM 2.5 concentration in dry and wet seasons (331.7 ± 190.7 µg m −3 ). Student (10-17 years old) PM 2.5 exposures ranged from less than 10 µg m −3 to more than 150 µg m −3 (mean 56 µg m −3 ) in four neighborhoods in Accra, Ghana (Arku et al, 2015), much lower than that for students at the WB site (356.9 ± 71.9 µg m −3 ). It can be seen that the high PM 2.5 exposure of students in this study was likely related to waste burning emissions, while there was no obvious strong PM 2.5 emission source in the study of Arku et al (2015).…”

Exposures to and origins of carbonaceous PM2.5 in a cookstove intervention in Northern Ghana

“…That study reported average personal exposure to BC of 8.8 µg/m 3 and average cooking area BC of 14.5 µg/m 3 . Arku et al (2015) performed personal PM 2.5 sampling in Accra, the national capital located along the coast in Southern Ghana, as part of a 'spatial sources and exposure' study. That work found average PM 2.5 mass concentrations of 56 µg/m 3 , with differences in exposure based on gender and neighborhood affluence.…”

“…Summary statistics for the EC, OC, and organics are shown separately for personal and microenvironmental samples in The observed average PM 2.5 personal exposures in REACCTING appear lower than comparable previous works, although it must be emphasized that here the sum of EC and OC is reported, while the following works used total gravimetric PM 2.5 mass. In Ghana, personal PM 2.5 sampling was performed on high school students in Accra, Ghana, (Arku et al, 2015), where they found average 24-h concentrations of 56 µg/m 3…”