Using Factor Analysis to Attribute Health Impacts to Particulate Pollution Sources

Abstract

Laden et al. (2000) recently reported results of applying factor analysis to data taken in six cities from 1979 to 1988, identifying airborne particle sources potentially affecting daily mortality. These authors sought relationships between source groups and risk measures using source tracer elements, Se (coal combustion), Pb (light-duty motor vehicle sources), and Si (crustal--soil dispersion). Combined data analyses of this kind may overlook the complexity of source contributions, which have common tracer elements. In one of the cities, Boston, for example, the authors found coal combustion was an important source of mortality risk. For the city of Boston, the authors attribute coal combustion largely to distant upwind regional sources. The emphasis on coal combustion is confounded by the presence of major local sources of residual oil combustion, which contribute V, Se, and S (sulfur as sulfate) to the source apportionment. Evaluation of the source identification using single-element tracer analysis indicates that the detailed chemical composition or profile of major local sources needs to be taken into account in these investigations to minimize misclassification of airborne particle sources with potential adverse health effects.

Evaluating the application of multipollutant exposure metrics in air pollution health studies

“…First, a marker can be emitted by several sources within a sampling area and may not be specific to a sole source (Grahame and • Does not account for changes in PM composition Hidy, 2004). Second, marker species may be highly reactive in the atmosphere and have complex spatial variability so that the variability of more stable pollutants within the source mixture is not captured.…”

“…al. (2000) Intake Fraction  Examines the impact of perchloroethylene emissions from dry cleaners in the United States  For many compounds, like perchloroethylene, the uncertainty inherent in the estimation of cancer potency or source emissions would dominate these small errors Fann et al (2013) Source Apportionment  Uses photochemical model (CAMx) to quantify PM 2.5 and O 3 sources in the US during 2005 and the future  Draws association between sources and morbidity during the two time periods Grahame and Hidy (2004) Marker Species  Demonstrates that source identification using single pollutant marker species may be confounded due to the…”

Decavanadate effects in biological systems

“…Vanadium is a heavy metal with increased environmental circulation, resulting from various anthropogenic activities [29][30][31] and it is of great concern due to its toxicity and accumulative behavior at specific target organs, such as the liver and kidney, inducing oxidative damage, lipid peroxidation and changes in haematological, reproductive and respiratory systems [32][33][34][35][36]. Formation of reactive oxygen species (ROS) induced by vanadium in biological systems may involve Fenton-like reactions [34], vanadate bioreduction mediated by reduced glutathione (GSH), flavoenzymes or nicotinamide adenine dinucleotide, reduced form (NADH), and nicotinamide adenine dinucleotide phosphate, reduced form, (NADPH) oxidases [37][38][39] or interaction with mitochondria [14].…”

Secondary Sulfate Effects?

“…In a reanalysis, Schwartz (2003) found that their traffic variable remained significant, but their regional “coal” variable became insignificant. We (Grahame and Hidy 2004) noted that among the six cities described by Laden et al (2000), Boston had the lowest levels of the “coal tracer” (selenium); only Boston had a significant association with an apparent coal source. Similarly, only in Boston was an association with SO 4 significant.…”

“…Similarly, only in Boston was an association with SO 4 significant. Finding that local residual oil sources emitted over half the Se and SO 4 in Boston, these authors (Grahame and Hidy 2004) concluded from toxicology that these results represented effects of residual oil emissions.…”