svetlana vasilievna , hello. good afternoon, svetlana vasilievna kostyan, deputy head of the republican center for analytical control in the field of environmental protection . the area of ​​professional activity is the formation and implementation of environmental policy in the field of sampling and measurements. svetlana vasilievna one of the areas of activity is the monitoring of superficial ones in the country, how do you are you doing? and most importantly, let's explain why to assess the state of water ecosystems of the republic of belarus, the so-called monitoring system for surface water bodies was created, which includes 297 observation points for 160 water bodies, this monitoring is carried out by 22 laboratories-centers for more than 30 indicators. indicators such as the temperature of dissolved oxygen nitrites. it is nitrate, and heavy metals, mercury, arsenic, lead, that is, these indicators are controlled in water. frequency different happens monthly happens once a year, let's say mercury controls once a year more than 2,000 samples are taken in rivers during the year, more than 60,000 are made. analyz