The Arctic Environmental Problems - New Ecoinformatics Tools in Environmental Science: Applications and Decision-making - page 545

where (e w , e * ) and (

* ) are the heavy metal concentrations in (water, sediments)
as solid and dissolved phases, respectively; Q i e ;w

ˈ w , ˈ

is the heavy metal input with the
AYRS tributaries (i = 1), by atmosphere precipitation (i = 2) and with industrial
wastes (i = 3);

i 2

a 1 is the solid fraction part in the bottom sediments and a is the

solid particles part in the i-th flow of heavy metals. The removal of heavy metals

from water by evaporation and sprays is neglected.
Approximate solutions of the initial value problem for the Eqs. ( 6.17 )

fl

- ( 6.29 ) are

realized by means of the quasi-linearization method (Nitu et al. 2000b).

6.5.3 In-Situ Measurements

To obtain the data for the AYRSSM database, the joint US/Russian expedition to
Siberia s Angara and Yenisey rivers was conducted in the summer of 1995

(Krapivin and Phillips 2001b; Phillips et al. 1997; Krapivin et al. 1997a, 1998a).
Sampling began at the town of Bolshaya Rechka on the Angara near Lake Baikal
and continued past the cities of Irkutsk, Angarsk and Bratsk, with a side trip on the
Kitoy River, near Angarsk. The expedition then proceeded to the Yenisey-Angara
junction. Sampling began near the village of Kulakovo, upstream on the Angara
and continued downstream to the junction with the Yenisey at the logging town of
Strelka. On the Yenisey, sampling began near the town of Kazachinskoye above the
junction and continued downstream past the industrial complex at Lesosibirsk
below the junction. Figure 6.14 shows points of measurement during this
expedition.
The water balance of the AYRS was calculated with the data given in Fig. 6.13 .
Some results from this expedition are given in Tables 6.14 , 6.15 and 6.16 .A
transportable radionuclide analysis system, consisting of a mechanically-cooled
germanium gamma-ray spectrometer in a lead shield, was set up on-site in Irkutsk.
Results of this analysis are given in Table 6.14 . An X-ray-

'

uorescent spectrometer
(XRF) was also set up on-site and used for screening of the samples for heavy
metals. After the expedition, samples were sent to a commercial laboratory for
elemental analysis. Results of this analysis are given in Tables 6.15 and 6.16 .
Results for each of these two categories of pollutants are discussed below.
Table 6.16 represents comparison of results (ppm) of the laboratory analysis of the
1996 expedition materials on the Angara water quality (Analytical Services Center
of Ecology and Environment, Inc., New York).
The manmade radioisotope 137 Cs (30-year half-life) was detected in all samples
analyzed from above the Irkutsk dam, with concentrations ranging from 2 to
12 Bq kg − 1 (dry weight). These values are consistent with background levels that
can be expected due to global fallout as a residual from atmospheric nuclear testing.
Below the Irkutsk dam in the vicinity of the cities of Irkutsk and Angarsk, the
measured 137 Cs concentrations ranged from <4 to 30 Bq kg − 1 , indicating that some
of the samples contained 137 Cs concentrations were signi

fl

cantly higher than the