1998, Vol. 20, No. 5 (September)
Air quality in Croatia
Air quality in settlements has been improving in the
last 10 years. The reasons for this improvement could be found in the
introduction of natural gas, introduction of heating facilities operated
from heating plants, substitution of coal with other fuel types and gradual
reconstruction of the Croatian economy towards environmentally cleaner
technologies. In 1995 the air protection law came into force, and the
problem of air pollution has been put under more systematic control.
Emissions inventories for eight pollutants (SO2,
NOx, NMVOC, CH4, CO, CO2, NH3
and N2O) have been established for Croatia in accordance
to the European programme for such emissions inventories. Emissions
have been determined for the time period 199095. In addition,
for the years 1990 and 1995 emissions of Hg, Cd and Pb have been determined
as well as emissions of stable organic compound for 1990 (Fig. 1).
Fig. 1. Emissions of pollutants for the
period 19901995 in Croatia.
Due to the war in Croatia, the standard of living
and economic activity were reduced, resulting in a reduced emission
of pollutants (Table 1).
|Table 1. Reduction of emission in 1995 in relation to 1990
The emission of sulfur dioxide has been reduced
by 65% mainly due to the reduction of the sulfur content in petrol fuels,
and the closing of some large industrial sources of SO 2 . NO
x emissions come from road traffic (41%), other traffic (28%), combustion
power plants (12.8%). Non-methane volatile organic compounds (NMVOC),
very important compounds for photooxidant production and global warming,
are mainly emitted from natural sources (49.2%), usage of solvents (15.1%),
road traffic (20.3%) and nonenergetic industrial processes (5.9%)1
Surface ozone measurements in Zagreb, the capital of Croatia, were
performed as early as the end of the 19th century, but the first ozone
measurements using automatic monitoring equipment took place in the
centre of Zagreb in the spring and summer of 1975.
Continuous measurements of photochemical air pollution in the atmospheric
boundary layer above Zagreb (8 years mean ozone value 25 p.p.b., but
with very pronounced diurnal variation due to local effects) and the
nearby elevated Puntijarka site (980 m a.s.l.)(8 years mean ozone value
40 p.p.b.)2 were supplemented by summer season measurement
campaigns along the Adriatic coast 3,4
, which has greater insolation and Mediterranean flora with many different
sources of NMVOC. Locations along the Adriatic coast were chosen so
as to be representative of tourist resorts at different distances from
larger pollution sources. Starting from the north, one site was on Krk
island in Malinska, relatively close (25 km SSE)
to the city of Rijeka. The second monitoring site was on the island
of Iz in the central Adriatic, which can be considered to be isolated
from larger pollution sources. The third site was in the southern Adriatic
in Hvar on the island of Hvar, an important tourist resort (Fig. 2.).
|Fig. 2 Distribution of hourly average ozone
volume fractions obtained at different sites along the adriatic
coast in Croatia
To characterize a measurement site, an index defined
as the average ratio between the maximum and minimum daily hourly average
ozone volume fraction was introduced 3,4
. Zero values for hourly averages were assigned the value 0.4 p.p.b.
in order to avoid division by zero. For urban sites with strong photochemical
pollution, this index has a value of over 10, in the upper boundary
layer and above, where there are no sources of precursor molecules which
act also as sinks during nighttime, it is less than 2. In less polluted
urban and suburban sites as well as in some rural locations, where some
photochemistry takes place, it will be of the order of 2 to 5 reflecting
formation around noon and destruction during the night 4
. The corresponding values for five measurement sites in Croatia are
compared in Table 2.
|Table 2. Index of photochemical pollution
for five different sites in Croatia
|Rovinj (northern Adriatic)
|Iz (central Adriatic)
|Hvar (southern Adriatic)
1. Neæak J, Jelaviæ
V. The proceedings of the Symposium on air protection, pp. 31-42, 1997,
2. Klasinc L, Butkovic V, Cvitas
T, Kezele N, Lisac I, Lovric J. In: Øystein Hov (ed.) Tropospheric
Ozone Research, Springer, Berlin, 1997, pp. 222-229.
3. Cvitas T, Klasinc L. Boll. Geofisico,
1993, 16, 521-527.
4. Cvitas T, Kezele N, Klasinc L,
Lisac I. Pure Appl. Chem., 1995, 67, 1450-1453. Nenad Kezele and Leo
Klasinc, Rudjer Boskovic Institute, PO Box 1016, 10001 Zagreb, Croatia