[Evaluation of the biological significance of changes in the organism under external influence]

Estimation of the statistical reliability and the biological significance of changes caused by external actions are two independent parts of data analysis. Statistical reliability is a criterion of the reality. The principal unhealthy effects are decreasing of living term and increasing of morbidity. Other effects seem harmful on the basis of physiological analysis, and those are less reliable. Increasing of harmful effects frequency, but not the parameters values changes (if opposite is not proved), is a criterion of unhealthy effects.