Factors influencing the escape and spread of harmful substances

Currently, harmful substances are released to the air more often and they threaten the safety of people because of their increasing amount being operated, stored and transported in the Czech Republic. The present thread is that the disasters in which harmful substances are released do not occur sporadically. Unintentional release may appear during their treatment, storage or transportation for many reasons, especially due to a natural disaster, technical cause or human failure. New causes of release have occurred recently {--} malicious intent and terrorist attack.This thesis creates a complex view of the branches of science and other areas dealing with the spread of harmful substances in the air. Emission of harmful substances is influenced by many factors which are very difficult or sometimes impossible to model mathematically. There exist a lot of mathematical models which differ according to the factor they treat. They concern models of outflow, dispersion and evaporation.The fire brigade in České Budějovice uses only one calculation model for estimating the emission of harmful substances - model ROZEX 2001.The result of this thesis may be used as a model for analysis and assessment of harmful substance release