mouths, the southern extremity of the Romanian littoral, and occasionally offshore
up to 90 nautical miles (Bologa 1994; Bologa et al. 1995). The monitoring
programme has resulted in a fairly extensive database covering the last 20 years.
A network of stations including the whole area between the Danube mouths
(Sulina) and the southern limit (Mangalia), from the shoreline to 90 n.m. offshore
has been used for radioactivity monitoring in the Romanian Black Sea sector.
Romanian studies thus particularly focused on computing the concentration of
137 Cs and
90
Sr for sediment and seawater in the pre-Danubian sector of the Black
Sea. Gamma spectrometry was used for analyzing emerged and submerged sediments, seawater, macroalgae, invertebrates and fish of marine origin (Bologa et al.
1991).
The highest content of artificial gamma emitters was noticed in 1986, followed
by its subsequent decrease in all components, excepting submerged sediments that
are a sink for the isotopes. Environmental CFs for
137 Cs and
90 Sr in different Black
Sea biota were also estimated (Fig. 18.1). The radiometric investigations of the
coastal marine ecosystem showed the presence of the long-lived anthropogenic
radionuclides
90 Sr and
137 Cs (Table 18.1). Significant
90 Sr activities (0.53–8.6 Bq.
kg dry weight (d.w.) were found in the submerged sediments collected from seven
profiles between the northern and southern limits of the Romanian littoral
(Table 18.1). The maximum values were recorded at the pre-Danubian zone, in
good generally correlation with quality and origin of the sediments. For 1998 the
90
Sr level ranged from 2.1 to 7.8 Bq.kg
À1 d.w. in 1999 from 3.1 to 8.3 Bq.kg
À1
d.w. Emerged sediments were under lower limit of detection (<1.8 Bq.kg
À1 d.w.),
emphasizing small influence of the aquatic environment and their processes.
The continued monitoring of marine radioactivity is necessary either for
avoiding of any nuclear risk and for comparative radio-metric studies in the coastal
zone (Patrascu and Bologa 1990; Bologa and Patrascu 1998; Bologa et al. 1998).
The knowledge and conservation of the environmental factor quality can be
supported only by concrete results (Fig. 18.2).
Romanian monitoring data of the annual concentrations of gamma emitting
radionuclides were used in the IAEA and national data bases.
18.2.2 Ukrainian Marine Research
The Black Sea is one of the most contaminated marine basins in the Northern
Hemisphere; since the 26 April 1986 Chernobyl disaster, the Black Sea has been a
sink for Chernobyl-associated radionuclides. It has been estimated that ~2 PBq of
137 Cs were directly deposited by the atmosphere onto the water surface of the
Black Sea.
Most previous papers investigating fluvial transport of Chernobyl debris into the
Black Sea have focused on
137 Cs and
90 Sr. Also associated with direct atmospheric
fallout as well as fluvial transport, however, are nonvolatile radionuclides from fuel
particles, including transuranium elements (Np, Pu, Am, Cm).
302
A. Strezov
up to 90 nautical miles (Bologa 1994; Bologa et al. 1995). The monitoring
programme has resulted in a fairly extensive database covering the last 20 years.
A network of stations including the whole area between the Danube mouths
(Sulina) and the southern limit (Mangalia), from the shoreline to 90 n.m. offshore
has been used for radioactivity monitoring in the Romanian Black Sea sector.
Romanian studies thus particularly focused on computing the concentration of
137 Cs and
90
Sr for sediment and seawater in the pre-Danubian sector of the Black
Sea. Gamma spectrometry was used for analyzing emerged and submerged sediments, seawater, macroalgae, invertebrates and fish of marine origin (Bologa et al.
1991).
The highest content of artificial gamma emitters was noticed in 1986, followed
by its subsequent decrease in all components, excepting submerged sediments that
are a sink for the isotopes. Environmental CFs for
137 Cs and
90 Sr in different Black
Sea biota were also estimated (Fig. 18.1). The radiometric investigations of the
coastal marine ecosystem showed the presence of the long-lived anthropogenic
radionuclides
90 Sr and
137 Cs (Table 18.1). Significant
90 Sr activities (0.53–8.6 Bq.
kg dry weight (d.w.) were found in the submerged sediments collected from seven
profiles between the northern and southern limits of the Romanian littoral
(Table 18.1). The maximum values were recorded at the pre-Danubian zone, in
good generally correlation with quality and origin of the sediments. For 1998 the
90
Sr level ranged from 2.1 to 7.8 Bq.kg
À1 d.w. in 1999 from 3.1 to 8.3 Bq.kg
À1
d.w. Emerged sediments were under lower limit of detection (<1.8 Bq.kg
À1 d.w.),
emphasizing small influence of the aquatic environment and their processes.
The continued monitoring of marine radioactivity is necessary either for
avoiding of any nuclear risk and for comparative radio-metric studies in the coastal
zone (Patrascu and Bologa 1990; Bologa and Patrascu 1998; Bologa et al. 1998).
The knowledge and conservation of the environmental factor quality can be
supported only by concrete results (Fig. 18.2).
Romanian monitoring data of the annual concentrations of gamma emitting
radionuclides were used in the IAEA and national data bases.
18.2.2 Ukrainian Marine Research
The Black Sea is one of the most contaminated marine basins in the Northern
Hemisphere; since the 26 April 1986 Chernobyl disaster, the Black Sea has been a
sink for Chernobyl-associated radionuclides. It has been estimated that ~2 PBq of
137 Cs were directly deposited by the atmosphere onto the water surface of the
Black Sea.
Most previous papers investigating fluvial transport of Chernobyl debris into the
Black Sea have focused on
137 Cs and
90 Sr. Also associated with direct atmospheric
fallout as well as fluvial transport, however, are nonvolatile radionuclides from fuel
particles, including transuranium elements (Np, Pu, Am, Cm).
302
A. Strezov