Roadside PM10 and associated metals in Constantine, Algeria

Abstract

Samples of particulate matter less than or equal to 10 μm (PM10) were collected every other day using an Airmetrics MiniVol portable air sampler in Constantine, the third largest and most densely populated city of Algeria with a population of 600,000. The main objective of this study was to assess the concentrations of particulate matter (PM) with an aerodynamic diameter ≤10 μm (PM10), and dust-laden trace metals in a residential area with heavy traffic during two months, from 25 March 2010 to 24 May 2010. Furthermore, the present work examines the daily levels of metallic elements Fe, Zn and Cu. The PM10 concentrations ranged from 7.6 to 159.4 μg/m3 during the study period. WHO’s daily PM10 average guide value of 50 μg/m3 was exceeded 10 times over 31 samples. HYSPLIT back trajectories were used to identify the source locations of the pollutants. Rain scavenging of atmospheric particulate matter led to a substantial decrease in PM10 concentrations. During the study period, Zn was detected in one sample at a concentration of 0.78 μg/m3. It is believed that air masses originating from Iceland’s Eyjafjöll volcano may have transported clouds of ashes rich in Zn to the sampling site on that occasion. A maximum of 2.92 μg/m3 of Cu was observed when the volcanic cloud reached the sampling site four times during the corresponding 24-h sampling period.