The progress of civilization as a whole (urbanization, demographical explosion and massive concentration of humans in towns and cities, vertiginous industrialization, the intense development of the motorized traffic, the chemical substances used in agriculture and even in the domestic economy etc.) has profoundly altered the living environment of human beings. The numerous synthetic substances, which have the economy of modern society, the use of which is a component of our daily life in this century, exert a series of effects upon the human organism, which for many of these substances are only partially known or even unknown. In the majority of cases, these substances show quickly their efficiency in the benefit of society, while their negative effects on man and environment are realized only much to late. It is the case of the pesticides, heavy metals, polycyclic hydrocarbons, other polluting agents that were analyzed and monitored in this paper.