A new NMVOC speciated inventory for a reactivity-based approach to support ozone control strategies in Spain

Ozone (O3) pollution is a persistent problem in many regions of Spain, so understanding O3 precursor emissions and trends is essential to design effective control strategies. We estimated the impact of Non-Methane Volatile Organic Compounds (NMVOC) species upon O3 formation potential (OFP) using the maximum incremental reactivity approach. For this, we developed a speciated NMVOC emission inventory for Spain from 2010 to 2019 combining national reported emissions with state-of-the-art speciation profiles, which resulted in a database of emissions for over 900 individual NMVOC species and 153 individual sectors. Additionally, we analysed 2030 emission projections to quantify the expected impact of planned measures on future OFP levels. Overall, the main activities contributing to OFP in Spain are paint manufacturing and applications (20 %), manure management (16 %), and domestic solvent use (6 %). These activities contribute unevenly across regions. The more urbanised areas report a larger contribution from the solvent sector (64 % in Madrid), while in rural areas, manure management and agricultural waste burning gain importance (24 % in Extremadura), indicating that local control measures should be implemented. The top 10 NMVOC species contributing to OFP are ethanol, ethene, xylenes, propene, toluene, formaldehyde, 1,3-butadiene, styrene, n-butane, and cyclopentane, which together are responsible for 54 % of the total OFP. Our trend analysis indicates a reduction of NMVOC emissions and OFP of -5 % and -10 % between 2010 and 2019, respectively. The larger decrease in OFP is driven by a bigger reduction in xylenes (-29 %) and toluene (-28 %) from paint application industries and the road transport sector. By 2030 a significant increase (+37 %) in the OFP from the public electricity sector is expected due to the planned increase in biomass use for power generation. Our results indicate that policies should focus on paint reformulation, limiting aerosol products, and implementing NMVOC control devices in future biomass power plants.

The research leading to these results has received funding from the Ministerio para la Transición Ecológica y el Reto Demográfico (MITECO) as part of the Plan Nacional del Ozono project (BOE-A-2021-20183); from the Ministerio de Ciencia, Innovación y Universidades (MICINN) as part of the BROWNING project RTI2018-099894-B-I00; from the VITALISE project (PID2019-108086RA-I00) funded by MCIN/AEI/10.13039/501100011033; from the AXA Research Fund; and from the European Research Council (grant no. 773051, FRAGMENT). K. Oliveira acknowledges the support received by the grant PRE2020 − 092616 funded by MCIN/AEI/10.13039/501100011033 and ESF Investing in your future. The authors would also like to acknowledge M.J. Alonso, J. Pérez-Ilzarbe, and N. Alonso from MITECO for the information provided on the emission inventory and their feedback on the analysis of the results; to Antonella Gutierrez (TRAGSATEC) for her input on the parts of the manuscript related to emission legislation, and to Dr. Erika von Schneidemesser (IASS) for her feedback on the title of the paper. We thank the anonymous reviewers for their careful reading of our manuscript and their many insightful comments and suggestions.

Peer reviewed