The Mobile Source Effect on Curbside 1,3-Butadiene, Benzene, and Particle-Bound Polycyclic Aromatic Hydrocarbons Assessed at a Tollbooth

Abstract

On-road mobile sources contribute substantially to ambient air concentrations of the carcinogens 1,3-butadiene, benzene, and polycyclic aromatic hydrocarbons (PAHs). The current study measured benzene and 1,3-butadiene at the Baltimore Harbor Tunnel tollbooth over 3-hr intervals on seven weekdays (n ϭ 56). Particle-bound PAH was measured on a subset of three days. The 3-hr outdoor 1,3-butadiene levels varied according to time of day and traffic volume. The minimum occurred at night (12 a.m.-3 a.m.) with a mean of 2 g/m 3 (SD ϭ 1.3, n ϭ 7), while the maximum occurred during the morning rush hour (6 a.m.-9 a.m.) with a mean of 11.9 g/m 3 (SD ϭ 4.6, n ϭ 7). The corresponding traffic counts were 1413 (SD ϭ 144) and 16,893 (SD ϭ 692), respectively. During the same intervals, mean benzene concentration varied from 3 g/m 3 (SD ϭ 3.1, n ϭ 7) to 22.3 g/m 3 (SD ϭ 7.6, n ϭ 7).Median PAH concentrations ranged from 9 to 199 ng/m 3 .Using multivariate regression, a significant association (p Ͻ 0.001) between traffic and curbside concentration was observed. Much of the pollutant variability (1,3-butadiene 62%, benzene 77%, and PAH 85%) was explained by traffic volume, class, and meteorology. Results suggest Ͼ2-axle vehicles emit 60, 32, and 9 times more PAH, 1,3-butadiene, and benzene, respectively, than do 2-axle vehicles. This study provides a model for estimating curbside pollution levels associated with traffic that may be relevant to exposures in the urban environment.

Exposure to second‐hand smoke air pollution assessed from bar patrons' urinary cotinine

“…As a basis for comparison, in the Wilmington study the outdoor PPAH levels averaged 27 ng/m 3 (SD528) on the first visit, when the outdoor RSP levels averaged 11 mg/m 3 (SD53.2), and 3 ng/m 3 (SD51.9) on the second visit, when outdoor particle levels averaged 2.0 mg/m 3 (SD51.9). By way of further comparison, the peak 3-hr median PPAH at a Baltimore, Maryland, Harbor Tunnel tollbooth was 199 ng/m 3 (early morning rush hour; Sapkota & Buckley, 2003). Mean estimated PPAH levels in the present study were nearly identical to this other value.…”

The effects of roadside structures on the transport and dispersion of ultrafine particles from highways

“…Several air quality monitoring studies have measured elevated concentrations of a number of air pollutants near roadways including ultrafine particles (UFP, aerodynamic diameter o0.1 mm) (Zhu et al, 2002a, b;Sapkota and Buckley, 2003;Kittelson et al, 2004). The majority of particulate matter (PM) mass emitted by motor vehicle combustion occurs in the PM 2.5 size range, with mass median diameters generally between 0.1 and 0.2 mm for gasoline and diesel vehicles (Cadle et al, 1999;Durbin et al, 1999;Kleeman et al, 2000).…”

Estimating Exposure to Polycyclic Aromatic Hydrocarbons: A Comparison of Survey, Biological Monitoring, and Geographic Information System–Based Methods

“…It is not clear, however, how well these measures capture personal exposures to vehicle exhaust or how they relate to each other. Vehicle exhaust is a major contributor to the concentration of polycyclic aromatic hydrocarbons (PAH) in urban areas and near major roads (17,18). Several PAHs are classified as probable human carcinogens based on evidence from occupational and laboratory animal studies (19,20), making these compounds of primary interest for epidemiologic studies of cancer and exposure to vehicle exhaust.…”