THE ACTUAL IMPACT OF WASTE-TO-ENERGY PLANT EMISSIONS ON AIR QUALITY: A CASE STUDY FROM NORTHERN ITALY

In recent decades there has been an intense debate about the impact of waste-to-energy (WTE) plant emissions on air quality, and therefore on public health. Currently available data from emissions inventories show the negligible impact of waste incineration on air quality. A number of impact assessment studies are currently available too. A few of them are site-specific, but none of them makes a direct comparison between the local impact of the emissions from a WTE plant and emissions from other "common" sources (such as vehicles and domestic heating) perceived as less potentially hazardous in the public opinion. This paper examines the impact on air quality of actual emissions from a WTE plant in the municipality of Desio (located to the North of Milan in the Lombardy region) using CALPUFF atmospheric dispersion model. Continuous emission monitoring data were used to measure the plant's actual emissions of PM10, NOx, cadmium, and dioxins (PCDD/F) as inputs for model simulations. For comparison purposes, the impact of traffic emissions along the main roads in Desio was also simulated. The results of the model show that the WTE plant has a marginal impact on local air quality compared with pollution from vehicular traffic. The contribution of the plant's actual emissions to ambient pollution concentration levels in the urban area of Desio is between two (NOx and cadmium) to four (PM10 and PCDD/F) orders of magnitude smaller than the contribution from road traffic emissions.