[Human health risk from the chemical composition of drinking water].

The maintenance and development of the centralized household underground water supply system in the closed administrative-territorial entity Seversk, Tomsk Region, when the aquifers are inadequately protected and there is a hydrological association of individual aquifers with polluted surface waters require a hygienic estimation based on the use of a risk methodology, including that considering the regional feature of sanitary situation establishment. No risk realization has been ascertained for damage to critical organs and systems in pediatric and adult populations under the population influence of the chemical substances available in drinking water.

[Analyzing the population's health risks from the influence of environmental factors of various nature in vicinity of the Siberian chemical complex].

The paper provides the results of calculating the risks to human health in the cities of Seversk and Tomsk. The cancer risk from man-caused radiation is 2 orders of magnitude lower than that from air pollution with chemical carcinogens. Air contamination of classical chemical pollutants presents a major hazard to human health.

[Novel diagnostic possibilities of transesophageal stress echocardiography with electrical atrial pacing].

In order to develop simple technique of combination of transesophageal echocardiography (TEE) and transesophageal pacing, to create algorithm and protocol of transesophageal stress-echocardiography, and to study possible complications and methods of their elimination we examined 39 subjects (mean age 50 +/- 7.2 years) with suspected ischemic heart disease (IHD), 22 patients with arterial hypertension, 11 patients with episodes of ischemic changes on 24 hour ECG. In 11 patients with high blood pressure (BP) and 2 patients with frequent ventricular extrasystoles veloergometry was contraindicated, and in 3 patients veloergometry was not informative due to complete left bundle branch block. We suggested a device for simultaneous transesophageal echocardiography (TEE) and transesophageal pacing which consisted of transesophageal multiplane ultrasound cardiological transducer and electrode for transesophageal pacing. During test pacing frequency was increased stepwise from 120 140 and to 160 beats per min until appearance of ischemia or achievement of submaximal heart rate (HR). During intubation of esophagus HR and systolic BP increased from 80.2 +/- 11.5 to 102 +/- 12.5 b/min and from 130 +/- 23.6 to 149.1 +/- 17.5 mm Hg, respectively. Magnitude of double product rose from 104.4 +/- 29.4 to 149.4 +/- 32.3. This served as additive stress factor, facilitating more precise diagnosis of IHD. As a result various derangements of regional myocardial contractility were revealed in 14 patients (36%). These derangements were accompanied with ischemic ECG changes in 72% and with mitral regurgitation - in 43% of cases. The test was stopped prematurely in 1 patient because of paroxysm of reciprocal atrioventricular tachycardia. Simplicity of the proposed device, lack of complications allow to recommend it for clinical application. Anatomical proximity of esophagus and the heart, average 20 mm Hg elevation of BP, rising cumulative myocardial oxygen requirements augment reliability of the method in diagnostics of IHD.