Chemistry Reference
In-Depth Information
Fig. 5 Fuel-based emission inventory from domestic and international shipping during the period
1984-2008 [
53
]
source apportionment techniques [
54
,
55
]. As fuel oil is enriched in V and Ni content
with respect to the crust, these metals were generally used as markers to identify the
fuel oil combustion source. Measurements of aerosol chemical composition made on
the island of Lampedusa, south of Sicily, revealed the influence of heavy fuel oil
combustion emissions due to the elevated Ni and V soluble fraction and high V and
Ni to Si ratios. Back trajectories analysis suggested that air masses prevalently came
from the Sicily channel region, where intense ship traffic occurs [
56
].
For the Eastern Mediterranean Basin the impact of shipping emissions on the
urban air quality has been hardly investigated. Only a few studies report on the
contribution to ambient PM levels by shipping emissions. Recently, Tzannetos [
57
]
calculated that the PM
2.5
emissions due to ship activity within the passenger port of
Piraeus constitute 15% of the total emissions within the greater area of Athens.
Karanasiou et al. [
17
] attributed the relatively high sulphate concentrations in the
urban aerosol of Athens to the emissions from ships from the port of Piraeus.
5.5 Secondary Aerosol
5.5.1 Secondary Inorganic Aerosol
Sulphates (SO
4
2
), ammonium (NH
4
+
) and nitrates (NO
3
) are the main secondary
inorganic aerosol ions as they account for about two thirds of the total ionic mass
in PM
1
and for about 50% in PM
10
in Athens [
21
]. These ions represent two
different major source categories: fuel combustion and vehicular circulation.
Theodosi et al. [
21
] studied the spatial variability of these ions in 2 sites within
GAA: Lykovrisi (LYK) and Goudi (GOU). LYK is a moderately populated munic-
ipality, in the northern part of the GAA, 10 km from the city centre; GOU is located
