Air quality study in the coastal city of Crotone (Southern Italy) hosting a small-size harbor.

Particulate polycyclic aromatic hydrocarbons (PAHs), n-alkanes, and gaseous pollutants were collected from the harbor and the urban area of Crotone (Southern Italy) in October 2015. The atmospheric concentrations of organic substances associated to PM10 were determined daily, while gaseous pollutants (BTEX, O3, SO2, NOx, NO2, and NH3) were monitored on monthly basis by means of diffusive sampling. Total PAHs reached, on the average, 1.56 ± 0.72, 0.33 ± 0.14, and 0.59 ± 0.37 ng/m3 at the urban monitoring stations (Fiore, Fermi) and at the harbor, respectively. The percent distribution and diagnostic concentration ratios of PAHs were similar at Fermi and harbor, whereas differences were found through comparison with Fiore site. Biogenic n-alkanes (n-C29, and n-C31) were the most abundant components, indicating the important impact of terrestrial higher plants in all sites. On the other hand, n-C23-n-C25 homologs originated from incomplete combustion of fossil fuel were not negligible (CPI2.5 = 2.4) in harbor, confirming the role of anthropogenic sources there. Inside the harbor, SO2 concentrations ranged from 5.6 to 14.8 μg/m3 showing the maximum value within the old part of the harbor (touristic port). A statistical significant difference between the harbor and the surroundings was indeed observed for this pollutant, which is a specific marker of ship emissions. The other gaseous species monitored did not exhibit the same distribution, with exception of NH3 and benzene, whose concentration values ranged from 2.8 to 6.9 μg/m3 and 0.3 to 1.4 μg/m3, respectively, and peaked at the same harbor site. Similarities were found in NOx, NO2, and O3 concentration distributions, showing high values in the New Port area.