Field Validation of Polyethylene Passive Air Samplers for Parent and Alkylated PAHs in Alexandria, Egypt

• Published in: Environmental science & technology Vol. 46; no. 7; pp. 3990 - 3998
• Main Authors: Khairy, Mohammed A, Lohmann, Rainer
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 03.04.2012
• Subjects: Air Pollutants - analysis; Air pollution; Air Pollution - analysis; Alkylation; Analysis methods; Applied sciences; Atmosphere - chemistry; Atmospheric pollution; Cities; Egypt; Emissions; Environmental Monitoring - instrumentation; Exact sciences and technology; Kinetics; Petrochemicals; Pollution; Polycyclic aromatic hydrocarbons; Polycyclic Aromatic Hydrocarbons - analysis; Polyethylene; Polyethylene - chemistry; Seasons; Temperature; Uncertainty; Winter; Africa; Egypt; Alexandria Egypt; Validation; Hydrocarbon; Urban area; Polycyclic aromatic compound; Mutagen; Persistent organic pollutant; Measuring instrument; Carcinogen; Passive detection; Low density ethylene polymer; Sampler; Air pollution; Sampling; Organic compounds
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es300012u

Polyethylene samplers (PEs) were deployed at 11 locations in Alexandria, Egypt during summer and winter to test and characterize them as passive samplers for concentrations, sources, and seasonal variations of atmospheric concentrations of polycyclic aromatic hydrocarbons (PAHs). PE–air equilibrium was attained faster for a wider range of PAHs during the winter season possibly due to increased wind speeds. Calculated PE–air partitioning constants, K PE‑A, in our study [Log K PE‑A = 0.9426 × Log K OA – 0.022 (n = 12, R 2 = 0.99, Std error = 0.053)] agreed with literature values within <46%. For parent (except naphthalene), mono- and dialkylated PAHs, active sampling based concentrations of PAHs were within an average factor of 1.4 (1.0–5.6) compared to the PE based values. For C3–4 alkylated PAHs, K PE‑A values were lower than predicted, on average by ∼0.8 log units per carbon in the alkylation. Enthalpies of vaporization (ΔH vap) accurately corrected K PE‑As for temperature differences between winter and summer sampling. PAH profiles were dominated by naphthalene, phenanthrene, and alkylated phenanthrenes. Calculated diagnostic ratios indicated that PAHs originated mainly from vehicle emissions.