QUALITY OF DRINKING WATER AND ADOLESCENTS’ TASK PERFORMANCE IN THE SOUTH OF THE RUSSIAN FAR EAST

Aim of the study: hygienic assessment of the combined effect of harmful substances and biogenic elements consumed with drinking waters on the task performance of adolescents in the South of the Russian Far East by simultaneous screening. Methods. Seven settlements in the Primorsky Territory were investigated. The content of chloroform, tetrachlorethylene, Fe, Mn, Si and the ratio Ca/Mg were assessed in tap water. 283 schoolchildren aged 15-16 were examined. The questionnaire method was used to determine the daily consumption of Fe, Mn, Ca, Mg, Si with tap, bottled (45 trade marks) and filtered (5 home filter models) water. The actual average total daily dose (AADD) of consumption of the substances with drinking water was calculated. Screening of adolescents' task performance in the settlements was carried out synchronously on February 8 and 9, 2017 at 8:50 - 10:30 AM. Anfimov's table was used for assessing task performance. The number of viewed letters, productivity coefficient, indicators of total errors and differentiation errors were taken into account. The relationship between AADD of substances and task performance was assessed using methods of paired rank (Rs) and multivariate partial (Rch) correlation analysis. Results. In some settlements, tap water contains a lot of Fe (0.74 mg/L), Mn (0.18 mg/L), Si (67.11 mg/L) and very little Ca (7.89 mg/L) and Mg (1.54 mg/l) against the background of safe concentrations of chloroform, tetrachlorethylene. The correlation dependences between productivity coefficient indicator and Ca/Mg ratio (Rs = +0.86; p ≤ 0.01) in girls, viewed letters indicator and the Mn-Fe-Ca/Mg complex when eliminating the influence of Si (Rch = -0.88; p ≤ 0.001) in girls and (Rch = -0.74; p ≤ 0.01) in boys, differentiation errors indicator and Mn-Si-Ca/Mg complex when eliminating the influence of Fe (Rch = +0.52; p ≤ 0,05) in boys were established. According to the scientific literature, the revealed correlations have a set of features typical of the cause-effect relationships. Conclusion: deficiency and imbalance of Ca and Mn in drinking water against the background of its contamination with Mg, Fe and a natural excess of Si is a real risk factor for reducing task performance in adolescents of the Primosky Territory.

tap water, filtered water, bottled water, task performance, adolescent population, simultaneous screening