EVALUATING ECOLOGICAL SAFETY OF URBANIZED AREAS WITH ACCOUNT FOR BELOW-THRESHOLD VALUES
A new approach is proposed for the evaluation of ecological safety based on the comparison of actual technological processes with the ideal one and determining ‘the best available technology’ with the highest level of environmental protection. The most common ecological evaluation methods regarding the sanitary and hygienic standards, as well as the acceptable impact standards, do not allow to perform an exhaustive evaluation of an ecosystem’s limits of resistance to anthropogenic impacts, and consequently, to give an all-round assessment of the ecological safety of the environment for human life and activities. The lower safety threshold values of maximum allowable concentrations have shown a downward trend in respect of magnitudes of values, particularly for impacts of different carcinogenic substances and ionizing radiation, which may show effect on the genetic level. It is shown that it is necessary to improve the evaluation of the ecological safety of the environment for human life and activities taking into consideration the below-threshold criteria of the anthropogenic impact based on the scientific approach to ecological idealization. An additional evaluation criterion of ecological ideality is introduced, which makes it possible to determine the degree of deviation (closeness) of the actual process from the ideal ecological process at the initial stage, and consequently, to choose ‘the best available technology’. On the basis of the introduced criterion, additional quantitative indicators have been developed to evaluate technological and technology-related process in terms of their impact on the urban environment, taking into account the below-threshold factors of ecological safety in accordance with the natural background: ‘relative deviation of a local process from the ideal one’, ‘acceptable non-ideality limit’, as well as integral quality evaluation indicators for the urban environment.