335 



The available official data on the contamination of air, water and soil in 

 Novosibirsk oblast do not provide the full picture of the environmental situation in this 

 region (and its constituent areas), yet they can effectively indicate zones of possible 

 anthropotechnical stress, which can result in damage to the health of the population. 



In Tomsk oblast, a substantial increase in the background radiation is found at the 

 mouth of the Chemilshchikova Chaimel where water coming from the Tomsk-7 area 

 flows into the River Ob: 100 m from the bank, water registers 30 /ir/hr, and the general 

 background is 30-35 /xr/hr. It must be taken into account that contaminated water at the 

 measuring point has been already diluted substantially with water from the 

 Chemilshchikova Channel of the River Ob. The fact that the general background 

 radiation in the River Ob and its tributaries is significantly lower (1-4 iir/hi) than the 

 above values suggests that industrial production in the city of Tomsk-7 is related to these 

 levels of the atmospheric background and river background in adjacent areas. 



In the Krasnoyarsk kray, in 1989-1991 the Krasnoyarsk Scientific Center of the 

 Siberian Branch of the Russian Academy of Sciences conducted investigations of the 

 radioecological conditions of the Yenisey River. An airborne gamma-ray survey and 

 comprehensive investigations were performed 1,000 km downstream of the discbarge 

 from the Mining Chemical Integrated Works, using a specially equipped vessel. Over 

 600 samples of water, bottom sediments, soil, fish and vegetation were taken along a 

 section 1,000 km long. The investigations covered the entire radionuclide composition of 

 contaminants, including plutoniimi, tritium, and also cesium- 137 and phosphorus-32 (the 

 main dose-forming radionuclides). 



It was found that in the zone of displacement of discharged water from the 

 integrated works, sodium-24 and manganese-S6 reached the highest concentration, 

 Z6-lQr'' Ci/1 and 2.3-10"' Ci/1 respectively, exceeding the 76/82 radiation safety 

 standards by 10 and 2 times, respectively. In the town of Atamanovo, the first settlement 

 downstream from the discharge site, the concentration of certain nuclides in water was 

 below permissible concentrations due to decay and dilution, but the total activity in water 

 was close to the upper limit of the permissible value. 



The content of long-lived radionuclides (cobalt-60, cesium-137, europium-152, 

 154) on the bottom of the Balchugovsky Channel, for the average water content, was 

 about 1 CL The entire reserve of technogenic nuclides in the tailings of the islands Aat 

 were studied is estimated at approximate^ 17 Ci. The distribution of radionuclides 

 through the bed varies greatly along the length of the river. 



During the investigation, much attention was given to the study of radioactive 

 contamination of fish. Altogether over 40 sp>ecimens of thirteen nonmigratory and 

 migratory species of fish were analyzed. The main nuclides accumulating in fish tissue 

 were pbosphorus-32, zinc-65, cesium-137, and, close to the source of activity, sodium-24. 

 Contaminated fish were caught at a great distance from the site of discharge, both 



