4.3.3. Impact Assessment

There are many works in which the environmental impact assessment is carried out taking into account a small number of indicators, of which the CO2 emissions are the most popular [35,36]. Despite the importance of the emission of CO2, a complete impact assessment must consider a set of indicators that represent a complete environmental profile. That implies the use of environmental

impact assessment methods. These methods can be separated depending on the approach used: midpoint or endpoint. On one hand, the midpoint approach defines the environmental profile by means of a set of impact categories. One of the most popular methods that take into account the midpoint approach is the CML. On the other hand, the endpoint approach defines the environmental profile considering only a small set of damage categories. One of the most frequently used methods that consider the endpoint approach is the Eco-indicator. Both approaches are necessary to carry out a complete environmental interpretation of the bridge. On one hand, the midpoint approach can provide a more accurate and complete environmental profile. On the other hand, the endpoint approach can be easier to interpret. For these reasons, the environmental impact assessment method used in this work is the ReCiPe method [18], whose main objective is to provide a combination of the Eco-indicator and CML, considering the midpoint and endpoint approaches.
