The Relationship between Polycyclic Aromatic Hydrocarbons and Heavy Metals

Abstract

Background : Heavy metals and PAH s in flue gas have received considerable attention in recent years due to their mutagenic or carcinogenic properties. PAH s are products of incomplete combustion of carbonaceous compounds at high temperatures. Heavy metals are released into the ambient air from the same sources as those earlier mentioned for PAH s . The present study was carried out to investigate the influence of the quantity of heavy metals on PAH s formation in ambient air. Methods : In this study, air particulates were collected on glass fiber filters using a high- volume air sampler. Each filter was exactly cut into equal pieces. One piece was digested with HNO 3 as well as H 2 O 2 and used for determination of heavy metals. Another piece was extracted using Soxhlet method. The latter was used for the determination of PAH s . The concentrations of heavy metals (Cr, Cd, Cu, Pb, and Zn) were measured using Perkin- Elmer atomic absorption spectrometer. The concentration of PAH s was measured by a PU4400 gas chromatograph equipped with FID detector. The concentrations of PAH s and heavy metals were determined in different seasons. Results : The results showed that the concentration of PAH s was minimum in the weekend and holidays, but maximum in winter. The relationship between ambient air concentrations of PAH s and heavy metals was investigated and an excellent agreement was found. The general trend of variations in concentration of heavy metals were found very similar to PAH s , therefore it could be concluded that the source of pollution was the same for both of pollutants. Conclusion : The general trend of variations in concentration of heavy metals was found very similar to PAH s , therefore it could be concluded that the source of pollution was the same for both of pollutants.