Natural and anthropogenic sources of chromium, nickel and cobalt in soils impacted by agricultural and industrial activity (Vojvodina, Serbia).

This study reports the contents and sources of chromium, nickel and cobalt, as well as Al, Ca, Mg, K, Fe and Mn in Vojvodina regions Srem and Central Banat area soil samples. Different methods were applied to identify the sources of the studied elements and to classify the latter as geogenic and/or anthropogenic: modified Tessier sequential extraction, calculation ratio of E/Al, XRPD, correlations and cluster analysis. The sampling methodology was according to the GEMAS project. The results show that increasing content of chromium, cobalt and nickel detected in studied soils can be explained by a distribution pattern and the presence of ultramafic and mafic parent rocks, as well as by significant anthropogenic pollution, mainly originating from the industry at some localities. The statistically significant difference between the content of Cr and Ni in soils of Srem and C. Banat is observed. The content of the studied elements is higher in soils of Srem. The normalization to Al indicating a presence of the anthropogenic sources which my significantly affect the content of Cr and Ni in the soils from Beocin, Ruma and Stara Pazova. There is no shown influence of eventual agrochemicals application on the Cr, Ni and Co content.

Terrestrial radioactivity of the Jabal Eghei area in southern Libya and assessment of the associated environmental risks.

Activity concentrations of main terrestrial radioisotopes (226)Ra, (232)Th and (40)K were measured in geological samples collected in Libya's Jabal Eghei area, in order to contribute to the establishment of a baseline map of the environmental radioactivity levels and to estimate the associated environmental risk to the population. Activity concentrations ranged from 22 to 5256 Bq kg(-1) for (226)Ra, from 11 to 221 Bq kg(-1) for (232)Th and from 132.0 to 2304 Bq kg(-1) for (40)K. Using these results, representative risk factors were calculated: the total absorbed gamma dose rate in air (ranged from 25.5 to 2434.3 nGy h(-1) with a mean value of 251.8 nGy h(-1)), the radium equivalent activity (55-5281 Bq kg(-1), with the mean value of 537 Bq kg(-1)), external hazard index (0.149-14.24, with a mean value of 1.451) and annual outdoor effective dose (31.3-2985.4 µSv, with a mean value of 308.9 µSv). Accordingly, the radiation risk is above the world average, mainly as the consequence of discovered uranium anomalies.

Distribution of natural radionuclides in surface soils in the vicinity of abandoned uranium mines in Serbia.

The activity concentrations of natural radionuclides in soils from the area affected by uranium mining at Stara Planina Mountain in Serbia were studied and compared with the results obtained from an area with no mining activities (background area). In the affected area, the activity concentrations ranged from 1.75 to 19.2 mg kg(-1) for uranium and from 1.57 to 26.9 mg kg(-1) for thorium which is several-fold higher than those in the background area. The Th/U, K/U, and K/Th activity ratios were also determined and compared with data from similar studies worldwide. External gamma dose rate in the air due to uranium, thorium, and potassium at 1 m above ground level in the area affected by uranium mining was found to be 91.3 nGy h(-1), i.e., about two-fold higher than that in background area. The results of this preliminary study indicate the importance of radiological evaluation of the area and implementation of remedial measures in order to prevent further dispersion of radionuclides in the environment.