| Abstract |
Polycyclic aromatic hydrocarbons (PAH), a group of carcinogenic and mutagenic pollutants, are byproducts of incomplete combustions of organic materials such as wood, fossil
fuels, meat, and tobacco, and are therefore distributed ubiquitously in the ambient air, soil and water environments. PAH in the atmosphere, especially in densely populated areas, is
significantly affected by anthropogenic emissions, such as automobile exhaust, fossil fuel combustion, biomass burning, cigarette smoking, and industrial activities. Particulate matter
(PM) air pollution, especially fine particles with aerodynamic diameters less than 2.5 μm (PM2.5), has been linked to increased morbidity and mortality rates, as well as various adverse health effects such as respiratory and cardiovascular diseases. The association of PM2.5 with
toxic compounds such as PAHs could further increase the health effects. Human exposure to PAHs can occur through three routes, i.e. inhalation, ingestion and dermal absorption. For the
general population, the main exposure routes are inhalation of polluted air or cigarette smoke and ingestion of food containing PAHs.
Heraklion is a rapidly growing city, the largest urban centre in Crete. However, little is known on PAHs levels, especially PM2.5-bound PAHs concentrations in this area. To
characterize PM2.5-bound PAHs in Heraklion, a method was developed to provide sensitive and reliable measurements of 35 PAHs in archived 14-day PM2.5 samples collected with low flow rate (9,5 L/min or 20 m3 air/sample). Then PM2.5 samples, which were taken at ten
sampling sites (five as urban sites related with higher traffic, five as urban sites related with lower traffic characterized) during spring, summer and autumn 2009, were analyzed and the levels, seasonal and spatial variation of PAHs were studied. Samples also were taken from a
rural site (Finokalia Station, Crete, ECPL) and a semirural site (roof of Chemistry Department,
UoC Campus in Voutes, Heraklion) using high volume air samplers, collecting PM2.1 particles
(flow rate: 26.000 L/min or 1000 m3 approximately). Correlation analyses between PAHs and
other air pollutants such as PM2.5, PM10, NOx were conducted as well.
The arithmetic mean of PM2.5 concentrations in the urban environment was 16,47
(±3,05) μg/m3, from 12,33 μg/m3 to 22,39 μg/m3. The lowest PM2.5 concentration was observed in Finokalia station (11,15 μg/m3), while in the semirural site the concentration was 14,93 μg/m3. The arithmetic mean of PAH concentrations in the urban sites was 0,635 (±0,258)
ng/m3, from 0,159 ng/m3 to 1,210 ng/m3. The most abundant PAH members were BghiP
(0,134±0,064 ng/m3), BbF (0,091±0,039 ng/m3), BeP (0,068±0,030 ng/m3) and IP (0,086±0,049 ng/m3). Lower molecular weight PAH members showed lower concentrations, in contrast with the higher ones. The SPAHs concentration at Finokalia Station was 0,035 ng/m3, while at the semirural site was 0,590 ng/m3, which were lower in correlation with the respective
urban sites arithmetic mean PAH concentrations that season (autumn). The total BaPeq
exposure was 0,057 ng/m3. BaP contributed with 46% in SBaPeq
contributed with 15,8% and IP with 15,2%. The BaPeq percentage distribution presented
variation, depended on sampling site and seasonality in correspondence to the PAH levels seasonality. High rates of carcinogen equivalent PAHs (CANPAHseq) were presented (97- 99%). Principal Component Analysis (PCA), associated with diagnostic ratios revealed vehicle
emissions (gasoline and diesel engined) were the major sources for PM2.5-bounded PAHs in
the ambient air of Heraklion.
A lot of studies have been reported to assess high exposure to PAHs; however, limited information is available on the exposure of the general populations to PAHs in the environment.
Even less information is available on the temporal, intra- and inter-subject variability of these biomarkers. These results could be used for such purposes.
|
Collections
