title: Occupational exposure to roadway emissions and inside informal settlements in sub-Saharan Africa: A pilot study in Nairobi, Kenya.
abstract: Few studies examine urban air pollution in sub-Saharan Africa (SSA), yet urbanization rates there are among the highest in the world. In this study, we measured 8-hr average occupational exposure levels of fine particulate matter (PM2.5), black carbon (BC), ultra violet active-particulate matter (UV-PM), and trace elements for individuals who worked along roadways in Nairobi, specifically bus drivers, garage workers, street vendors, and women who worked inside informal settlements. We found BC and re-suspended dust were important contributors to PM2.5levels for all study populations, particularly among bus drivers, while PM2.5exposure levels for garage workers, street vendors, and informal settlement residents were not statistically different from each other. We also found a strong signal for biomass emissions and trash burning, which is common in Nairobi's low-income areas and open-air garages. These results suggest that the large portion of urban residents in SSA who walk along roadways would benefit from air quality regulations targeting roadway emissions from diesel vehicles, dust, and trash burning. This is the first study to measure occupational exposure to urban air pollution in SSA and results imply that roadway emissions are a serious public health concern.
authors.affiliation: Dept. of Planning, Public Policy, and Management, 1209 University of Oregon, Eugene, OR 97403-1209, USA, nngo@uoregon.edu.
authors.forename: Nicole S
authors.initials: NS
authors.lastname: Ngo
authors.affiliation: Institute of Nuclear Science and Technology, College of Architecture and Engineering, University of Nairobi, P.O. Box 30197, G.P.O., Nairobi, Kenya, mjgatari@yahoo.com.
authors.forename: Michael
authors.initials: M
authors.lastname: Gatari
authors.affiliation: Lamont-Doherty Earth Observatory, Columbia University, 61 Rt 9W, Palisades, NY 10964, USA, chilli@ldeo.columbia.edu (Chilrud) and yanbz@ldeo.columbia.edu (Yan).
authors.forename: Beizhan
authors.initials: B
authors.lastname: Yan
authors.affiliation: Lamont-Doherty Earth Observatory, Columbia University, 61 Rt 9W, Palisades, NY 10964, USA, chilli@ldeo.columbia.edu (Chilrud) and yanbz@ldeo.columbia.edu (Yan).
authors.forename: Steven N
authors.initials: SN
authors.lastname: Chillrud
authors.affiliation: Ecole Nationale Superieure d'Electricite et de Mecanique, kheira.bouhamam@ensem.inplnancy.fr.
authors.forename: Kheira
authors.initials: K
authors.lastname: Bouhamam
authors.affiliation: Department of Environmental Health Sciences, Mailman School of Public Health, Columbia University, 722 West 168th St., New York, NY 10032, USA, plk3@columbia.edu (Kinney).
authors.forename: Patrick L
authors.initials: PL
authors.lastname: Kinneym
keywords: Air pollution; PM2.5; black carbon; sub-Saharan Africa; urbanization; vehicle emissions