Comparative analysis of evaluation level of the chemical element concentration in human hair (mg/kg, dry weight)

Element	Average element content
	Tomsk oblast Mean ±Std Err (N=538)	1	2	3	4
Na	603 ± 25	650	12,9 ± 0,75	147	165
Ca	2626 ± 99	3200	678 ± 161	750	770
Sc	0,05 ± 0,004	n \ d	0,0098 ±0,0015	0,0014	0,0079
Cr	4,7 ± 0,4	3,8	1,09 ±0,1	0,167	0,558
Fe	522 ± 49	4300	87 ± 20,5	9,6	33,77
Co	0,26 ± 0,02	0,00295	0,13 ± 0,014	0,013	0,0762
Zn	182 ± 3,5	260	n \ d	142	n \ d
As	0,7 ± 0,03*	2,0	n \ d	0,085	0,158
Se	0,87 ± 0,15	n \ d	0,5 ± 0,7	0,830	n \ d
Br	12,6 ± 1,7	12,5	2,37 ± 0,016	37	6,82
Rb	1,9 ± 0,4*	23,5	1,97 ± 0,02	0,093	0,445
Sr	14,3 ± 0,7*	0,05	n \ d	1,20	n \ d
Ag	0,47 ± 0,6	3,45	0,18 ± 0,007	0,231	0,164
Sb	0,12 ± 0,07	6,5	0,1 ± 0,014	0,022	0,134
Cs	0,08 ± 0,004*	n \ d	n \ d	0,00067	0,708
Ba	15,4 ± 0,67*	5,0	n \ d	0,640	4,901
La	0,27 ± 0,01	n \ d	0,085 ± 0,02	0,035	0,043
Ce	0,4 ± 0,03	n \ d	0,18 ± 0,002	0,039	0,057
Sm	0,1 ± 0,01	n \ d	0,009	n \ d	n \ d
Eu	0,02± 0,001*	n \ d	n \ d	n \ d	n \ d
Tb	0,01 ± 0,0004*	n \ d	n \ d	n \ d	n \ d
Yb	0,05 ± 0,01*	n \ d	n \ d	n \ d	n \ d
Lu	0,008± 0,0005*	n \ d	n \ d	n \ d	n \ d
Hf	0,06 ± 0,004	n \ d	n \ d	0,0054	n \ d
Ta	0,04 ± 0,001*	n \ d	n \ d	0,0044	n \ d
Au	0,06 ± 0,01	0,08	0,02	0,030	0,0662
Hg	3,25 ± 0,4	6,0	n \ d	0,261	3,313
Th	0,07 ± 0,01	n \ d	n \ d	0,0013	n \ d
U	0,17 ± 0,01	n \ d	n \ d	0,057	n \ d

Notes: N – sample number; n\ d. – no data; * -average calculation based on samples, where 50% of the values are less than determination range; 1 - Man. Medico-biological data, 1977; 2 - Saet U. E. et al., 1990 – children living in non-black earth zone of Russia; 3 - Rodushkin I., Axelsson M.D., 2000. – adults living in north-east Sweden (N=114); 4 - Ward N.I. et. al., 1987. – adults and children from Sophia, Bulgaria (N=36).

There is a rather high U concentration in children hair samples from Irkutsk oblast and Pavlodar, Kazakhstan. The reason of which could be the natural peculiarities of these regions. Another important factor is the significantly low index ratio of Th to U in these regions (Th/U = 0.06), while in other regions it includes 0.4 – 0.5.

The regional hair differences in Tomsk oblast is reflected in its geochemical series (Table 4). In comparing the concentration coefficient, obtained in the normalization of average values, to indexes from reference data (Saet U. E. et al., 1990), it has been observed that there is a significant difference in obtained values for several elements which, in its turn, underlines the fact of various sources of this or that element.

The geochemical element spectrum in the hair of children from Tomsk oblast is rather diverse, and the concentration coefficient is more than 2 for practically the whole series. This fact proves the assumption that the hair element content in the population of Tomsk region is complex and predominantly includes specific technogenic features.

The geochemical series for Tomsk and Cheljabinsk oblasts are analogous (Table 4). Both series, i.e elements with coefficient more than 1, start with sodium and end in stibium. At the same time, there exist identical elements for both regions Na, Sm, La, Br, Co, Ca and Au, while the following elements are only characteristic of Tomsk oblast Fe, Sc, Cr, Ag, Ce, and where the series Sc is only found in Tomsk oblast. The same sources of an element explain such a common geochemical association of these two different regions.

The element spectrum within the geochemical series in the children hair from Irkutsk oblast mainly reflects natural component content. Based on comparative data of some authors (Saet U. E. et al., 1990), it should be noted that a high Fe content in hair is specific for Tomsk and Irkutsk oblasts, while selenium content only for Irkutsk oblast and Kazakhstan. High Ag concentration in investigated hair is a specific feature for Kazakhstan.

Tomsk oblast was conventionally divided into five zones in accordance to the extent of the technogenic environment transformations: (1) area with high extent of technogenic environment transformations; (2) regions with highly- developed petroleum production; (3) Tomsk region (the most intensive technogenic environment); (4) Seversk, where the Siberian Chemical Plant (SCP) is located; (5) populated areas located in the north-eastern direction from the Siberian Chemical Plant (zone of material transport by wind).

The element content in children hair in above-mentioned zones is shown in the following diagrams - Fig. 2 and Fig. 3.

Table 3.