• Energy Research

Across the 28 EU member states there were nearly half a million premature deaths in 2015 as a result of exposure to PM2.5, O3 and NO2. To set the target for air quality levels and avoid negative impacts for human and ecosystems health, the National Emission Ceilings Directive (NECD, 2016/2284/EU) sets objectives for emission reduction for SO2, NOx, NMVOCs, NH3 and PM2.5 for each Member State as percentages of reduction to be reached in 2020 and 2030 compared to the emission levels into 2005. One of the innovations of NECD is Article 9, that mentions the issue of "monitoring air pollution impacts" on ecosystems. We provide a clear picture of what is available in term of monitoring network for air pollution impacts on Italian ecosystems, summarizing what has been done to control air pollution and its effects on different ecosystems in Italy. We provide an overview of the impacts of air pollution on health of the Italian population and evaluate opportunities and implementation of Article 9 in the Italian context, as a case study beneficial for all Member States. The results showed that SO42- deposition strongly decreased in all monitoring sites in Italy over the period 1999-2017, while NO3- and NH4+ decreased more slightly. As a consequence, most of the acid-sensitive sites which underwent acidification in the 1980s partially recovered. The O3 concentration at forest sites showed a decreasing trend. Consequently, AOT40 (the metric identified to protect vegetation from ozone pollution) showed a decrease, even if values were still above the limit for forest protection (5000 ppb h-1), while PODy (flux-based metric under discussion as new European legislative standard for forest protection) showed an increase. National scale studies pointed out that PM10 and NO2 induced about 58,000 premature deaths (year 2005), due to cardiovascular and respiratory diseases. The network identified for Italy contains a good number of monitoring sites (6 for terrestrial ecosystem monitoring, 4 for water bodies monitoring and 11 for ozone impact monitoring) distributed over the territory and will produce a high number of monitored parameters for the implementation of the NECD.

This work investigates the possibility of implementing a nature-based solution (NBS) based on the photosynthetic process of Laurus nobilis L. (common laurel), for reducing peak CO2 concentrations in an air-tight museum environment, namely the Refectory of the Santa Maria delle Grazie Church (Milan, Italy), home of Leonardo da Vinci’s painting “Last Supper”. The phytoremediation potential of laurel plants was evaluated at CO2 ≅ 1000 ppm under controlled environmental conditions. Furthermore, light-saturated net assimilation (Pnmax) was measured at two CO2 concentrations (380 and 1000 ppm) during the growing season. Steady-state gas exchanges were not affected by elevated CO2 in the short-term, while Pnmax was significantly increased, also showing higher values in spring and autumn, and a reduction during summer. Our estimated CO2 removal rates indicate that, in order to control visitors’ respiratory CO2 emissions in view of an increase in visitor numbers in the Refectory, a possible NBS in the form of an external greenhouse, connected to the HVAC system of the museum, should allocate from 58 to 112 young laurel plants, depending on their seasonal phytoremediation capacity. These results, although preliminary, allow to hypothesize the possibility of controlling CO2 indoors through a combination of traditional air-cleaning systems and a properly designed NBS, thus increasing the sustainability of air-tight museum environments.

Urban forests provide important ecosystem services, such as urban air quality improvement by removing pollutants. While robust evidence exists that plant physiology, abundance, and distribution within cities are basic parameters affecting the magnitude and efficiency of air pollution removal, little is known about effects of plant diversity on the stability of this ecosystem service. Here, by means of a spatial analysis integrating system dynamic modeling and geostatistics, we assessed the effects of tree diversity on the removal of tropospheric ozone (O3) in Rome, Italy, in two years (2003 and 2004) that were very different for climatic conditions and ozone levels. Different tree functional groups showed complementary uptake patterns, related to tree physiology and phenology, maintaining a stable community function across different climatic conditions. Our results, although depending on the city‐specific conditions of the studied area, suggest a higher function stability at increasing diversity levels in urban ecosystems. In Rome, such ecosystem services, based on published unitary costs of externalities and of mortality associated with O3, can be prudently valued to roughly US$2 and $3 million/year, respectively.