Occurrence of aliphatic and aromatic compounds associated with atmospheric particulate matter in three cities of Gujarat, India

Abstract

The organic pollutants associated with atmospheric particulate matter (PM) in the environment, especially PM2.5 (particles <2.5 μm) have become a major issue worldwide in the past decade. The ambient air samples of four different sizes of particles were collected using an active air sampler (cascade impactor) from three cities of Gujarat: Anand, Ahmedabad and Surat. To study morphology and elemental composition, Scanning electron microscope (SEM) and Energy dispersive X-ray system (EDX) were used for fine particle size <1.0 μm. Besides, organic pollutants associated with particulate matter were analyzed using Gas Chromatography-Mass Spectrometry (GC–MS). Total 54 organic chemicals including 29 aliphatic (alkanes and alkanoic acids) and 25 aromatic chemical compounds were identified qualitatively. Phthalate, the well-known plasticizer was found in the atmosphere of all three study sites. In addition, polycyclic aromatic hydrocarbons (PAHs) such as naphthalene and fluorene were quantified at high concentrations in Ahmedabad (315 ng/m3 and 509 ng/m3 respectively) followed by Surat (310 ng/m3 and 382 ng/m3) and Anand (76.1 ng/m3 and 123 ng/m3). The distribution of organic chemicals was found diverse at three locations which might be influenced by the different sources and landmass usage in each city. The presence of the carbonaceous elements in the particles indicates biomass burning emissions during the winter season which might be a source of pollutants in the studied areas.