4 research outputs found
Use of X-ray Absorption Spectroscopy To Speciate Manganese in Airborne Particulate Matter from Five Counties Across the United States
The purpose of this study is to characterize manganese oxidation
states and speciation in airborne particulate matter (PM) and describe
how these potentially important determinants of PM toxicity vary by
location. Ambient PM samples were collected from five counties across
the US using a high volume sequential cyclone system that collects
PM in dry bulk form segregated into ācoarseā and āfineā
size fractions. The fine fraction was analyzed for this study. Analyses
included total Mn using ICP-MS and characterization of oxidation states
and speciation using X-ray absorption spectroscopy (XAS). XAS spectra
of all samples and ten standard compounds of Mn were obtained at the
National Synchrotron Light Source. XAS data was analyzed using Linear
Combination Fitting (LCF). Results of the LCF analysis describe differences
in composition between samples. MnĀ(II) acetate and MnĀ(II) oxide are
present in all samples, while MnĀ(II) carbonate and MnĀ(IV) oxide are
absent. To the best of our knowledge, this is the first paper to characterize
Mn composition of ambient PM and examine differences between urban
sites in the US. Differences in oxidation state and composition indicate
regional variations in sources and atmospheric chemistry that may
help explain differences in health effects identified in epidemiological
studies
Ghana randomized air pollution and health study (GRAPHS): study protocol for a randomized controlled trial
Background: Household air pollution exposure is a major health risk, but validated interventions remain elusive. Methods/Design The Ghana Randomized Air Pollution and Health Study (GRAPHS) is a cluster-randomized trial that evaluates the efficacy of clean fuels (liquefied petroleum gas, or LPG) and efficient biomass cookstoves in the Brong-Ahafo region of central Ghana. We recruit pregnant women into LPG, efficient cookstove, and control arms and track birth weight and physician-assessed severe pneumonia incidence in the first year of life. A woman is eligible to participate if she is in the first or second trimester of pregnancy and carrying a live singleton fetus, if she is the primary cook, and if she does not smoke. We hypothesize that babies born to intervention mothers will weigh more and will have fewer cases of physician-assessed severe pneumonia in the first year of life. Additionally, an extensive personal air pollution exposure monitoring effort opens the way for exposure-response analyses, which we will present alongside intention-to-treat analyses. Major funding was provided by the National Institute of Environmental Health Sciences, The Thrasher Research Fund, and the Global Alliance for Clean Cookstoves. Discussion Household air pollution exposure is a major health risk that requires well-tested interventions. GRAPHS will provide important new evidence on the efficacy of both efficient biomass cookstoves and LPG, and will thus help inform health and energy policies in developing countries. Trial registration The trial was registered with clinicaltrials.gov on 13 April 2011 with the identifier NCT01335490