The Republic of Kazakhstan has a long history of mining activities, viz., gold and uranium. Mining activities represent sources of potential naturally occurring radionuclides contamination of the environment and human health of population. The aim of this study was to investigate the radiation situation of industrially modified environment in Stepnogorsk areas of Kazakhstan to understand the sources of contamination. Quite high values of ambient equivalent dose rates in air ~2.87 μSv h−1 were found in the Aqsu gold-mining site. The radon equivalent equilibrium volume activity (indoor) were in the range of 313–858 Bq m−3 in the study area buildings. The high values of activity concentration of natural radionuclides found in Aqsu soil samples were 226Ra-4060, 232Th-1170 and 40K-4080 Bq kg−1, respectively. However, our comprehensive surveys implied that the increased natural radiation background caused by the radionuclide transport from the tailing area did not have an impact, while evaluation of its potential radiation risks and remediation of the territories of the former gold mining should be needed.

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The Stepnogorsk area Northern Kazakhstan has a long history mining activities. Mining activities have lots of environmental and health impacts. The aims of this study were to characterizing the general radiological situation of the area and evaluate radiation exposure by scenarios in settlements. In this study radiological assessment was performed for critical group living in the territory contaminated with radionuclides; working and studying at school located on territory former mining site. The annual dose burden is 2.5 mSv y−1 in Zavodskoy, 1.9 mSv y−1 in Kvartsitka and 3.6 mSv y−1 in Aqsu; and exposure from radon is around 11 mSv y−1 at the ground floor, and for teachers - up to 12 mSv*y−1. At settlements, however, under the hypothesis that all food contaminated with radionuclides and vegetables is cultivated locally in the territories with high background level, exposure from ingestion is 9.1 mSv y−1 in Zavodskoy, 8.3 mSv y−1 in Kvartsitka and 11.5 mSv y−1 in Aqsu. The combined effects of environmental problems have culminated into health problems. There are such possibility of the higher prevalence of cardiovascular, digestive and respiratory systems so it is necessary to evaluate or protect people living in Stepnogorsk area.

The present study is based on a pilot study, which showed that the Stepnogorsk area of Northern Kazakhstan represents sources of potential contamination of the living environment. The aim of the study was measurement of outdoor gamma radiation levels, activity concentration in soil samples and assessment of external exposure to the public. According to our analysis, the highest ${\boldsymbol{H}}^{\ast}$(10) values ∼2870 nGy h−1 were detected in the Aqsu school territory, which were slightly higher than the control readings for this region. The average 226Ra, 232Th and 40K activities were 617.8 ± 3.2 Bq kg−1, 188.3 ± 2.9 Bq kg−1 and 731.5 ± 6.2 Bq kg−1, respectively. The annual effective dose received by the Aqsu population ranged from 0.08 to 3.5 mSv y−1, which was found higher by an order of magnitude than the upper annual dose limit. Changes in radiation background are an unfavourable factor for the population and may possibly become potential radiation risks for long-term effects.