Ambient levels of volatile organic compounds in the vicinity of petrochemical industrial area of Yokohama, Japan

Urban ambient air concentrations of 39 aromatic (including benzene, toluene, and xylenes) and aliphatic volatile organic compounds (VOCs) were measured in Yokohama city, Japan. Yokohama city was selected as a case study to assess the amount of VOC released from Industrial area to characterize the ambient air quality with respect to VOC as well as to know the impact of petrochemical storage facilities on local air quality. For this purpose, ambient air samples were collected (from June 2007 to November 2008) at six selected locations which are designated as industrial, residential, or commercial areas. To find out the diurnal variations of VOC, hourly nighttime sampling was carried out for three nights at one of the industrial locations (Shiohama). Samples were analyzed using gas chromatographic system (GC-FID). Results show strong variation between day and nighttime concentrations and among the seasons. Aliphatic fractions were most abundant, suggesting petrochemical storage facilities as the major source of atmospheric hydrocarbons. High concentrations of benzene, toluene, ethyl benzene, and xylene (BTEX) were observed at industrial locations. BTEX showed strong diurnal variation which is attributed to change in meteorology. During our campaign, low ambient VOC concentrations were observed at the residential site

Ozone photochemical pollution over the north of algeria: Cartography and modelling

Tropospheric ozone cartography was established for the first time over the north of Algeria in this work. A set of 50 passive sampling tubes were distributed over Algiers city. The cartography was carried out by the ArcGIS software. The results shows that the highest O3 levels were mainly recorded in the east part of Algiers and to a lesser degree, in the west part. In addition, the ozone data of the Algiers Air Quality Monitoring Network was used to test the RAMS-EPS3-CAMx model system for ozone over the north of Algeria. It shows that there is relatively good agreement between the measured and predicted data with a clear diurnal ozone distribution. The ozone spatial evolution obtained from observation and modelling was relatively similar albeit some registered deviations

Exposure levels and health risk of PAHs associated with fine and ultrafine aerosols in an urban site in northern Algeria

Size distribution of toxicants in airborne particulates remains insufficiently investigated in Algeria. A 1-year campaign was performed at Bab Ezzouar, Algiers (Algeria), aimed at characterizing particulates for their physical and chemical features. For this purpose, scanning electronic microscopy (SEM), Raman spectroscopy (RaS), and GC-MS methodologies were applied. The samples were collected on daily basis by means of a high-volume sampling (HVS) system equipped with cascade impactor separating three size fractions, i.e., particles with aerodynamic diameters d < 1.0 μm (PM1), 1.0 μm 2.5), and 2.5 μm 10), respectively. The organic fraction was recovered from substrate through solvent extraction in an ultrasonic bath, separated and purified by column chromatography, then analyzed by gas chromatography coupled with mass spectrometry (GC-MS). Investigation was focused on polycyclic aromatic hydrocarbons (PAHs) and the concentration ratios suitable to investigate the source nature. Further information was drawn from SEM and Raman analyses. Total PAH concentrations ranged broadly throughout the study period (namely, from 4.1 to 59.7 ng m-3 for PM1, from 2.72 to 32.3 ng m-3 for PM2.5 and from 3.30 to 32.7 ng m-3 for PM10). Both approaches and principal component analysis (PCA) of data revealed that emission from vehicles was the most important PAH source, while tobacco smoke provided an additional contribution