Assessment of traffic-related air pollution in two street canyons in Paris: implications for exposure studies

Vardoulakis, Sotiris; Gonzalez-Flesca, Norbert; Fisher, B.E.A.

doi:10.1016/s1352-2310(01)00288-6

Cited by 121 publications

(60 citation statements)

References 36 publications

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“…The same was also observed for other pairs of VHCs and for the experimental toluene-to-benzene ratio, as will be discussed later. Vardoulakis et al 1 31 after field experiments in Paris, by Pfeffer et al 32 in two German cities, and Palmgren et al 33 in Copenhagen indicating similar types of emissions. The horizontal gradient of VHCs was also measured.…”

Section: Resultsmentioning

confidence: 88%

“…These results agree with previous findings for CO and NO x . 1,13 In regular street canyons, with H/W ratio approximately equal to 1 (H/W ϭ 1.2 for Patission), synoptic winds with speed values greater than 2 m/sec and parallel or near parallel to the street axis favor pollution buildup on the curbside, while perpendicular winds and low wind speeds provide better dispersion conditions. 13,34 Differences between morning and night horizontal gradients were observed.…”

Section: Resultsmentioning

confidence: 99%

“…The values from this study are higher than those from the studies mentioned earlier and differ significantly with those reported in Paris for benzene. 1 Of course, direct comparison is not possible because of the measurement sites.…”

Section: Resultsmentioning

confidence: 99%

“…1,2 The representativeness of measurements by monitoring networks is disputed because the smallscale variability of traffic-related pollution is not evaluated. 1 In fact, these findings suggest a major revision of environmental policy concerning air quality monitoring in populated areas with strong emissions and limited natural ventilation. Environmental policy organizations have started to plan alternative monitoring schedules to fulfill this gap of knowledge.…”

Section: Introductionmentioning

confidence: 99%

“…To the best of our knowledge, few studies have been done concerning the dispersion of volatile hydrocarbons (VHCs) in street canyons. Recently, Vardoulakis et al 1 have studied the benzene-toluene-xylene fraction in two street canyons in Paris and have proposed a methodology for assessing air quality in urban microenvironments.…”

Section: Introductionmentioning

confidence: 99%

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Dispersion of Volatile Hydrocarbons in Urban Street Canyons

Bakeas

Siskos

2003

Journal of the Air & Waste Management Association

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Volatile hydrocarbons (VHCs) were monitored in two urban street canyons for 16 days. Measurements of 15 selected VHCs were performed simultaneously at three different sampling heights: at street level (2 m), at 8 m, and at the rooftop (25 m above the ground). The aim of the study was to investigate the factors responsible for the horizontal and vertical changes in VHC concentrations. Physical parameters controlling the concentration gradients (wind flow and speed) were enabled. It was concluded that dilution and dispersion decrease the concentrations of HCs emitted at street level by approximately a factor of 6 between rooftop and street levels. Low winds and winds parallel to the street axis were identified as the worst dispersion conditions. The correlation between the measured VHC concentrations gave an insight into their fate. An empirical relationship between CO and benzene was established. These results may have important implications in planning monitoring studies to support research on population exposure in urban areas.

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Section: Resultsmentioning

confidence: 88%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Dispersion of Volatile Hydrocarbons in Urban Street Canyons

Bakeas

Siskos

2003

Journal of the Air & Waste Management Association

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How to identify cross correlations: a statistical test with time lag and its application on air‐pollutant time series

Tóth

Balogh

2012

Journal of Chemometrics

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We developed a method to detect time-lag-dependent cross-correlation effects in time series. The method is a statistical test based on ANOVA with resampling, but the simple plot of the p-values in respect to the time lag provides an intuitive recognition of cross correlations as well. It is applied on meteorological and air-pollutant data measured in Budapest. We detected periodic and odd cross-correlation effects easily on the graphs, for example, the effect of weekend/weekdays on pollutants, an odd effect of solar radiation on humidity in the fourth quarter of the year, an opposite effect of solar radiation and height of mixing layer on CO at the same day opposite to the following days, and the prompt resuspension of PM10 caused by solar radiation in the fourth quarter of the year. We estimated the length of the cross-correlation effects on the air pollutants: 2-3 days of precipitation depending on the solubility of the pollutants, 3-4 days of wind, and 2-5 days for the cross reactions of NO 2 and O 3 . We found that yearlong time domain provides different correlation effects than seasonal ones for the same daily time lags. The visual comparison of the curves also helps to identify the time domains, which can be modeled similarly. Our method is an efficient tool to identify cross-correlation effects before modeling, because it enlarges the correlations undetectable in cross-correlation functions.

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