N-Alkanes and Polycyclic Aromatic Hydrocarbons in Deposition Dust and PM10 of Interiors in Touggourt Region, Algeria.

Abstract

The occurrence of pollutants in environment displays its maximum impact on human health and on the global "quality" of life in the places where humans spend most of their time, i.e., indoors. A field study was undertaken in the region of Touggourt, Algeria. The goal was that of obtaining information on the main sources of indoor pollutant emissions (n-alkanes and polycyclic aromatic compounds) associated with deposition dusts (DDs) and suspended particulates (PM10). A multi-service clinic, two schools, a coffee bar, three houses, and an asphalt distribution center were investigated. Forty-five samples in total were collected, including 31 deposition dusts and 14 airborne particulates. That would improve the current understanding of pollution features in central Algeria reached through previous investigations in the Touggourt region. Capillary gas chromatography coupled with mass spectrometric detection was adopted to determine the concentrations of n-alkanes and PAHs. In deposition dust, total n-alkanes (TNAs) ranged between 37 and 794ng/(m2 day) in the summer and 33-1,724ng/(m2 day) in the fall. Meanwhile, TNAs loads in the PM10 samples ranged between 778 and 2,024ng/m3. According to Carbon Preference Index (CPI), Cmax, and wax n-alkanes (WaxCn) approaches, both DD and PM10 were released overall by anthropogenic sources, though the contribution of natural emissions could not be neglected. Total polycyclic aromatic hydrocarbons (TPAHs) associated with DD ranged from 4.4ng/(m2 day) to 127ng/(m2 day) during the summer period, and 2.0-224ng/(m2 day) in the fall; TPAHs' concentrations in PM10 ranged between 40ng/m3 and 984ng/m3. Preliminary information about the sources of PAHs was drawn by calculating the concentration ratios between diagnostic pairs (DRs) of PAHs. According to PAH DR values, the pollution sources influenced at distinct extents all of the sites and locations investigated. Anyway, the PAH occurrence was associated with petrogenic sources, with the prevalence of gasoline fuel cars, at most sites. A wide variability was also observed by comparing the concentrations of pollutants observed in the summer and in the fall. This was in agreement with the results of n-alkanes emissions.