Brief Characterization of the Vashkovtsy and Kelmentsy Districts of Chernivtsi Oblast in Relation to the Iodine Content of Water and the Incidence of Goiter

Assistant A. S. Shvets

From the Department of Biochemistry, Chernivtsi Medical Institute

In this paper we present the results of investigations into the iodine content and degree of mineralization of drinking water in two districts of Chernivtsi Oblast: Vashkovtsy, where, according to B. B. Rodnyansky (1950), an average of 56.5% of the population is affected by goiter, and Kelmentsy, where goiter is either entirely absent or very rare.

The Vashkovtsy district is situated in the foothill zone, on the Prut–Seret watershed. As P. A. Kuchinsky (1948) notes, the predominant soils in this district are dark-gray podzolized soils developed on deep, medium sandy loams. The parent materials show clear signs of excessive moisture. Annual precipitation is 800 mm. The terrain reaches an elevation of 600 m above sea level. Soil permeability is very low, extending to a depth of 1.5 m. High density of the parent material and insufficient air in the deeper soil horizons are characteristic of the soils of this district. The dark-gray podzolized soils of the Vashkovtsy district are acidic. The average humus content of the arable horizon is 3%. Reduction processes occur at relatively shallow depths, leading to the formation of lower-valence compounds.

The groundwater table here lies close to the surface. The principal waterways along which the villages are situated are the Cheremosh River and its tributaries, the Berezhnitsa, Teplitsa, and others. The district’s population obtains its drinking water mainly from wells and rivers. Most wells are very shallow, ranging from 2.5 to 4 m in depth. An exception is the wells in the village of Zamostye, which range from 10 to 13 m deep. As a rule, wells are fed by near-surface groundwater.

Drinking-water samples in this district were taken from wells and rivers in the settlements most affected by endemic goiter: Sloboda Banilov, Chertoriya, Zamostye, and Vashkovtsy. A total of 34 samples were taken: 28 from wells and 6 from rivers. The water was analyzed for iodine content and mineralization. The analytical data for the Vashkovtsy district are as follows:

a) In the village of Sloboda Banilov, the removable hardness of river water is 2.50 mg-equiv.; total hardness, 3.48 mg-equiv.; and dry residue, 200 mg per 1 L of water.

Well water is somewhat more highly mineralized. Removable hardness ranges from 3.84 to 4.6 mg-equiv.; total hardness, from 5.30 to 5.64 mg-equiv.; dry residue, from 300 to 420 mg per 1 L of water; and iodine content, from \(0.1 \cdot 10^{-7}\) to \(1.5 \cdot 10^{-7}\%\). The iodine content of river water is somewhat higher than that of well water;

b) In the village of Chertoriya, the removable hardness of well water is greater than in Sloboda Banilov and ranges from 6 to 7.18 mg-equiv.; total hardness ranges from 17.36 to 20.64°; and dry residue ranges from 320 to 480 mg per 1 L of water. Iodine content ranges from \(0.1 \cdot 10^{-7}\) to \(0.4 \cdot 10^{-7}\%\);

c) In the village of Zamostye, removable hardness ranges from 0.64 to 0.89 mg-equiv.; total hardness, from 1.74 to 6 mg-equiv.; dry residue, from 220 to 700 mg per 1 L of water; and iodine content, from \(0.1 \cdot 10^{-7}\) to \(0.3 \cdot 10^{-7}\%\).

The iodine determinations are close to the figures for Chertoriya.

In Vashkovtsy, the district center, the population uses well and river water for drinking. Two rivers flow through the town—the Berezhnitsa and the Teplitsa, tributaries of the Cheremosh. The removable hardness of river water ranges from 2.82 to 7 mg-equiv.; total hardness, from 3.14 to 7.57 mg-equiv.; and dry residue, from 160 to 480 mg per 1 L of water. The removable hardness of well water is 5.78 mg-equiv.; total hardness is 7.37 mg-equiv.; and dry residue averages 360 mg per 1 L of water. Iodine content ranges from \(0.27 \cdot 10^{-7}\) to \(0.4 \cdot 10^{-7}\%\). Judging by the average mineral composition of the sources investigated in the district, river water is less mineralized than well water.

The mean iodine content by source is as follows: rivers, \(0.73\cdot10^{-7}\%\); wells, \(0.38\cdot10^{-7}\%\). The average iodine content for the Vashkovsky district is \(0.55\cdot10^{-7}\%\).

For comparison with the Vashkovsky district, we present the results of an investigation of the Kelmenetsky district. This district is located in the lowland zone of the Dniester–Prut watershed, which does not rise above 400 m above sea level. The lowland zone is warm and dry, especially in its eastern half. It is a forest-steppe zone. Annual precipitation here is 536 mm. The soil cover consists of a group of podzolized deciduous-forest soils. The dark-gray podzolized soils of the plateau and slopes of the Dniester–Prut watershed are less acidic and more saturated with bases than the dark-gray podzolized soils of the Seret–Prut watershed, where the Vashkovsky district is located, as shown by chemical analyses of soils from these districts. Groundwater here lies farther below the surface than in the Seret–Prut watershed. Drinking water in this district is obtained predominantly from wells, which range in depth from 10 to 12 m. In most cases the wells are stone-lined; wooden wells are less common. Sixteen samples were collected in the Kelmenetsky district from the settlements of Ivanovtsy, Larga, and Kelmentsy.

The removable hardness of well water in the Kelmenetsky district ranges from 6.98 to 11.16 mg-equivalents; total hardness ranges from 8.60 to 15.20 mg-equivalents; and dry residue ranges from 941 to 1393 mg per liter of water.

The elevated mineral content of the district’s drinking water is noteworthy.

The district’s average mineral content, expressed as dry residue, is 1270 mg/l; total hardness is 9.91 mg-equivalents; and iodine content ranges from \(1.8\cdot10^{-7}\) to \(2.5\cdot10^{-7}\%\).

A comparison of water mineralization data from the Vashkovsky and Kelmenetsky districts shows that the drinking water of the Kelmenetsky district has a substantially higher mineral content—\(3\frac{1}{2}\) times higher—than that of the Vashkovsky district. Dry residue increases along with total hardness. As for iodine content, it ranges from \(0.0\cdot10^{-7}\) to \(1.5\cdot10^{-7}\%\) in the Vashkovsky district and from \(1.8\cdot10^{-7}\) to \(2.5\cdot10^{-7}\%\) in the Kelmenetsky district. The iodine content of drinking water in the Vashkovsky district is clearly lower than in the Kelmenetsky district.

If the quantitative data on iodine content in the drinking water of the Vashkovsky and Kelmenetsky districts are compared with the percentage incidence of goiter, an inverse relationship is apparent: in the Vashkovsky district, the mean iodine content is \(0.55\cdot10^{-7}\%\), and the incidence of goiter is 56.5%. In the Kelmenetsky district, the mean iodine content is \(2.15\cdot10^{-7}\%\), and goiter is either absent altogether or occurs very rarely.

It should also be noted that iodine content depends on the terrain and the nature of the soils.

Chernozems are richest in iodine; podzolized soils contain less. The soils of the Vashkovsky and Kelmenetsky districts are almost identical in character: gray and dark-gray podzolized soils predominate. There is, however, a very substantial difference between the soils of these districts. The soils of the Vashkovsky district are more acidic than those of the Kelmenetsky district, and the groundwater here is closer to the surface, resulting in a number of gray podzolized soils showing signs of surface wetness. All this also affects iodine content. The acidic soils of the Vashkovsky district generally contain less iodine, whereas the soils of the Kelmenetsky district are more basic and contain more iodine.

References

Kuchinsky, P. Ya. In: Chernivtsi State University: Scientific Papers, vol. III, Soil-Geographical Sciences Series, issue I, Chernivtsi, 1948, pp. 3–21. — Rodnyansky, B. B. Vrachebnoye Delo, 1950, no. 10, pp. 935–938.

Received December 6, 1956.