Research

My research interests use an interdisciplinary approach toward studying indoor and outdoor air pollution in urban populations and their potential health impacts.  My major fields of study include development and health economics with a minor in atmospheric science.  

Research I'm currently involved in includes the following:
Brief descriptions of my research can be found below (also found in my C.V.):

“Evaluating at health impacts of reducing pollution emissions from buses in New York City”—Abstract:  Since the early 1990’s, New York City Transit has made major efforts to reduce pollution emissions from their bus fleet. Between 1995 and 2005, emissions of particulate matter from buses have decreased by 97%; buses built more recently emit much less relative to buses built earlier and are currently being phased out. Using data collected from NYC on daily routes of each bus along with bus age, I will compute street level measures of bus emissions. Using the exact street address of individuals discharged from the emergency department, I can measure the association between street level bus emissions and respiratory related illnesses and calculate a health benefit-cost ratio of New York City’s policies to reduce pollution emissions from buses.

"Air quality, socioeconomic status, and policy:  A case study in Nairobi" (with Patrick Kinney and Jacqueline Klopp)--Abstract:  Few studies exist that examine air quality in rapidly urbanizing areas in Sub-Saharan Africa and even fewer look at the spatial and socio-economic dimensions of air quality. In this study, we measure exposure levels of PM2.5 for individuals working in low-income, vulnerable occupations in Nairobi, Kenya, including street vendors, matatu drivers, mechanics and women who live and work in informal settlements.  At the same time, we are trying to understand potential sources of air pollution in low-income areas and how local residents view air pollution as an issue.  The second part of the project involves discussions with focus groups in Mathare, an informal settlement in Nairobi, on people’s awareness of air pollution and its potential health impacts. This part of the project will help us assess how scientific information, like results from the first part of this project, could be used as a potential policy tool in Nairobi.

“The effects of convective clouds on transport of pollutants using a numerically simulated flow field” (with Chin-Hoh Moeng and Jeff Weil) —Abstract: In the planetary boundary layer (PBL) (loosely defined as the layer < 1 km above the surface), pollutants travel smaller distances and have shorter residence times relative to those in the upper troposphere. As a result, understanding the processes by which pollutants can be transported to the upper troposphere is critical. One way this can occur is by deep convective cloud systems. In this study, we observe how deep convection influences the distribution of an insoluble or less soluble chemical species, like carbon monoxide (CO), O3, and NOx, within the troposphere. This is done by using a Lagrangian approach that traces particles along a simulated time-evolving, three-dimensional wind field associated with a deep convection system.

“Remote sensing techniques to measure urban air pollution in Sub-Saharan Africa” (with Daven Henze, Darby Jack, and Patrick Kinney) —Abstract: Population is expected to increase rapidly in the urban areas of Sub-Saharan Africa (SSA). As such, there is increasing concern over urban planning and coping with a growing urban population, including mitigating health and climate impacts of environmental problems. Of particular concern is air pollution. One possible alternative to measuring urban air pollution in SSA without in-situ observations is remote sensing. In this project, we use satellite data to identify sources of pollution over urban areas in SSA.