Abstracts: ISEE 20th Annual Conference, Pasadena, California, October 12-16, 2008: Contributed Abstracts
Aldehydes are known as toxics because of their adverse effects on public health, and therefore it is important to understand concentrations and source characteristics of aldehydes in urban communities. In this paper, concentrations of formaldehyde, acetaldehyde, propionaldehyde and acrolein were measured in an urban community in New Jersey from November 2005 through December 2006.
Three sites in the city of Paterson, which were dominated by industrial, commercial and mobile sources, were chosen as monitoring locations. For industrial and mobile sites, sampling systems were placed on school building roofs. Measurements were simultaneously conducted in the background site located in Chester, NJ, which is located about 36 miles west/southwest of Paterson, NJ. The Passive Aldehydes and Ketones Sampler Method (PAKS) was used for the aldehyde measurement.
Formaldehyde and acetaldehyde were found to be the most abundant ambient aldehydes at all sites. Nonparametric Bonferroni adjusted Wilcoxon tests showed no significant differences in aldehyde levels between sites (P > 0.1). There was also no significant seasonal variation at each site (P > 0.1). These results suggest that vehicle emissions were to be the dominant sources in the study areas. This was confirmed by a significant correlation of formaldehyde, acetaldehyde, and propionaldehyde among different sites. The concentration ratios of formaldehyde/acetaldehyde and acetaldehyde/propionaldehyde were calculated for each season within each site and then compared to literature values to investigate potential emission sources of aldehydes. The ratios for formaldehyde and acetaldehyde were between 1.15–5.71 and the ratio for acetaldehyde/propionaldehyde were between 1.42–9.23, suggesting there might be different sources in different seasons and sites. However, as the ratios were within the range reported in other urban areas (1.2–8.38), it indicated that the aldehyde compounds measured in this study were derived mainly from anthropogenic sources. Further analysis will be conducted to identify the contributions from secondary emissions to aldehyde pollution in the study areas.