In recent years, negative demographic phenomena are growing in Lviv region as well as in Ukraine on the whole. They are manifested in falling birth rates, rising mortality, rising morbidity which are inextricably linked with ecological imbalance and environmental degradation in general. The aim of our research was to identify the features of the degree of stress of the adaptation mechanisms, vegetative status and functional health (of population) of “radiation-clean” Lviv region and compare the results with the results of FEE of “radiation-contaminated” Vinnytsia and Chernihiv regions. We examined 1592 children of different ages and sexes living in Lviv region with the help of functional-vegetative diagnostics (FVD) of vegetative health by the method of V.G. Makats, which allows us to identify indicators of variance of vegetative levels that act as integral bioindicators of internal homeostasis. The bioelectrical activity of 12 symmetrical pairs of functionally active zones of the skin (24 PHASES), 12 on arms and 12 on legs, which reflect the functional activity of the sympathetic and parasympathetic nervous systems was studied. Atmospheric air pollution, drinking water quality, waste accumulation are the main factors that harm the health of the population. Emissions of pollutants into the atmosphere from stationary sources of pollution in Lviv region in 2019 were 16.7% less than in 2018. The overall dynamics of pollutant emissions in 2000-2019 was characterized by a downward trend, from 108.6 thousand tons in 2000 to 88.9 thousand tons in 2019. In 2019, 1.0% more waste was generated in Lviv region than in 2018. In 2019, 858 kg of waste was generated per capita in Lviv region, that is 99 tons per 1 km2. The Lviv region is not included in the radiation control zone of Ukraine and is considered to be «conditionally clean». While studying the variance of vegetative levels and, accordingly, the functional health of children in Lviv region in 2001-2006, we found that in female and male groups vegetative dynamics had a «sympathetic orientation» (critical functional stress of adaptation), so the percentage of surveyed children included in the zone of increase of sympathetic activity fluctuated from 36% in 2006 to 64% in 2004 in the female group under supervision and from 36,5% in 2003 to 55,7% in 2006 in male that is much higher than 15%. of the norms. The critical advantage of «sympathetic dispersion» is not ideal for functional health, but in this situation it indicates the absence of a «radiation component» of the integrated environmental pressure. Functional and ecological examination of Lviv region in 2001-2006 revealed its relation to the zone of «functional protection tension». We noted an opposite situation during long-term observations of the dynamics of functional health of children in Vinnytsia and Chernihiv regions which belong to the 4th zone of state radiation control. In addition, the children living in these regions were characterized by the development of persistent parasympathicotonia (vagotonia). While analyzing the state of functional health of children due to the vegetative coefficient (kV), which characterizes the adaptive potential of the population, it was found that at a rate of kV 0.95-1.05, which corresponds to the vegetative balance, in all gender groups and in all years of observation it is at much higher levels. Its average value ranged from 1.15 in 2002 to 1.30 in 2004 and 1.19 was the overall average for all years of observation. Speaking about children living in Lviv region, there are changes that reflect the imbalance of the autonomic nervous system towards the predominance of sympathetic regulation, accompanied by increased energy needs.Prolonged predominance of sympathetic regulation leads to depletion of energy reserves and, as a consequence, can provoke the emergence and development of diseases of various etiologies.