Obesity and metabolic syndrome associated with combined low-dose exposure to disruptor metals and chlorinated organic compounds in drinking water

The aim of the study was to examine peculiarities of obesity development under combined exposure to disruptor metals and chlorinated organic compounds among population and in an experimental study upon exposure to doses not exceeding the maximum permissible levels. Clustering was carried out according to indicators of total and primary obesity (E66) incidence among population of the Orenburg region in several age groups: 0-14 years, 15-17 years, 18 years and older, as well as among the total population. Hygienic assessment of drinking water taken from the centralized water supply system was performed on the territory of the selected clusters to identify levels of disruptor metals and chlorinated organic compounds and to check their conformity with the requirements fixed in the SanPiN 1.2.3685-21. Spearman's rank correlation analysis was carried out. The experimental study was conducted on male rats; in its course, the experimental group was given drinking water containing iron and 2,4-DA in concentrations corresponding to 0.5 MPC. Upon completion of the experiment, relevant indicators were measured in the lab animals including body weight, epididymal fat mass, and levels of the following hormones: insulin, leptin, T3, and T4. Clustering of municipalities revealed areas with high obesity prevalence among local population including areas with a 2.2-fold higher level of obesity among children aged 0-14 years, 3-fold among children aged 15-17 years and 1.8-1.9 times higher prevalence among adults against the reference areas and regional averages. The results of the model experiment revealed 20 % growth in body weight and 8 % growth in adipose tissue mass in the experimental group of lab animals. The level of insulin increased by 23 % and leptin by 1.2 times while the levels of T3 and T4 decreased by 27 % and 44 %, respectively. There are differences in indicators and statistically significant correlations indicating the need to further investigate cause-and-effect relations between obesity and effects produced by disruptors.