Risk Assessment and time evolution of Total Petroleum Hydrocarbons (TPH) Fractions in soils

Pratarolo Paolo Risk Assessment and time evolution of TPH Fractions in soils 5 1. Introduction Soil represents one of the most difficult environmental compartment to characterize, because it is a complex system, that can be defined in many ways depending on the discipline. One of its definitions is: “Soil is a three-dimensional body performing a wide range of socio-economic and ecological functions. It is a complex media formed by a porous matrix, in which air, water and biota occur together with the fluxes of substances and fluids between these elements. Alteration of soil processes leads to changes in the functioning of ecosystems, and many environmental problems which become apparent in other media actually originate within the soil” (Environmental European Agency, EEA 2013). Each of the land exploitation types (chemical, petrochemical, oil refinery, petrol stations …) represents a potential source of contamination for soil; particularly, as soil includes different environmental matrices and living being, any of these elements can be contaminated from a potential source. As shown by Figure 1, soil pollution can have different origins:  an industrial origin, due to the presence of a polluting industry failing to take all precautions necessary to prevent leakage  an agricultural origin, following the massive use of fertilizers or insecticides that seep into the soil.  urban-origin, due to the accumulation of domestic waste, the fallen freeway traffic ... The latter is also increasingly important, because nowadays most of population of Western Europe lives in cities and this causes the rising of different kinds of pollution. Soil pollution is becoming a difficult component of urban development that is faced by local communities and institutions in charge, both to ensure the health of populations and accompany economic development.