This paper presents a preliminary study for the evaluation of transport-related air pollution situations in an urban area. The authors utilize a geographic information system (GIS) which integrates a vehicle emission model, pollutant dispersion model, backward trajectory model and related databases to estimate the emissions and spatial distribution of traffic pollutants in Taichung, Taiwan, ROC...

Ozone pollution affects human health, especially in urban areas on hot sunny days. Its basic photochemistry has been known for decades and yet it is still not possible to correctly predict the high ozone levels that are the greatest threat. The CalNex_SJV study in Bakersfield CA in May/June 2010 provided an opportunity to examine ozone photochemistry in an urban area surrounded by agriculture. ...

[1] We use tropospheric NO2 columns from the Global Ozone Monitoring Experiment (GOME) satellite instrument to derive top-down constraints on emissions of nitrogen oxides (NOx NO + NO2), and combine these with a priori information from a bottomup emission inventory (with error weighting) to achieve an optimized a posteriori estimate of the global distribution of surface NOx emissions. Our GOME ...

Measurements of ozone and its precursors conducted within the HaChi (Haze in China) project in summer 2009 were analyzed to characterize volatile organic compounds (VOCs) and their effects on ozone photochemical production at a suburban site in the North China Plain (NCP). Ozone episodes, during which running 8-h average ozone concentrations exceeding 80 ppbv lasted for more than 4 h, occurred ...

[1] Nitrogen oxides (NOx ≡ NO + NO2) produced by lightning make a major contribution to the global production of tropospheric ozone and OH. Lightning distributions inferred from standard convective parameterizations in global chemical transport models (CTMs) fail to reproduce observations from the Lightning Imaging Sensor (LIS) and the Optical Transient Detector (OTD) satellite instruments. We ...

Effects of fleet modernization and use of diesel particle filters (DPF) and selective catalytic reduction (SCR) on heavy-duty diesel truck emissions were studied at the Port of Oakland in California. Nitrogen oxides (NOx), black carbon (BC), particle number (PN), and size distributions were measured in the exhaust plumes of ∼1400 drayage trucks. Average NOx, BC, and PN emission factors for newe...

The need to control exhaust emissions from stationary power sources is dictated by environmental regulations that limit the amount of smoke (particulates), sulfur dioxide, carbon monoxide, hydrocarbons, and oxides of nitrogen or NOx that can be exhausted into the atmosphere. In areas where atmospheric pollution is a serious concern, as in the Los Angeles basin, very low emission levels are dema...

BACKGROUND Recent findings suggest that exposure to outdoor air pollutants may increase the risk of allergic rhinitis. The results of these studies are inconsistent, but warrant further attention. The objective of the study was to assess the effect of relation between exposure to urban air pollution and the prevalence allergic rhinitis among school children. METHODS We conducted a nationwide ...

BACKGROUND Several studies have estimated associations between air pollution and birth outcomes, but few have evaluated potential effects on pregnancy complications. OBJECTIVE We investigated whether low-level exposure to air pollution is associated with gestational diabetes and preeclampsia. METHODS High-quality registry information on 81,110 singleton pregnancy outcomes in southern Sweden...

Vehicle emissions of nitrogen oxides (NOx), carbon monoxide (CO), fine particulate matter (PM2.5), organic aerosol (OA), and black carbon (BC) were measured at the Caldecott tunnel in the San Francisco Bay Area. Measurements were made in bore 2 of the tunnel, where light-duty (LD) vehicles accounted for >99% of total traffic and heavy-duty trucks were not allowed. Prior emission studies conduct...