Life cycle assessment of energy flow and packaging use in food purchasing

The aim of this project is to obtain quantitative data on the metabolic flows (energy consumption, not only by the establishment but also in the transportation of workers and customers, and packaging use) and their resulting environmental impacts of a standard shopping basket purchase in five city center municipal markets and a hypermarket in a suburban retail park in the province of Barcelona (Catalonia, Spain). The main results show that a standard shopping basket purchased in a retail park requires 20 times more energy than one purchased in a municipal market (11.1 kWh and 0.57 kWh, respectively). Customer transportation represents 83.2% of energy consumption in a retail park, while the greatest impacts in a municipal market stem from the establishment itself (49.5%) and worker transportation (40.4%). Secondly, the packaging use inventory is higher in a hypermarket (253 g) than in a municipal market (102 g). However, the overall environmental impact associated with a standard shopping basket is 10 times higher on average in a hypermarket than in a municipal market, and the carbon footprints of the hypermarket and the municipal market are 3.8 and 0.4 kg of CO 2 eq., respectively. According to the sensitivity analysis, current policies for reducing the amount of plastic bag packaging have little repercussion in a retail park because its relative weight in terms of total packaging use is only 7%. Nevertheless, they have notable effects in municipal markets where plastic bags represent 25% of the packaging use. Finally, if customers selected the least packaged products available in hypermarkets, each shopping basket could reduce up to 47.2% of its used packaging weight and between 15.4 and 59.0% of its associated environmental impact. © 2011 Elsevier Ltd. All rights reserved.