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 ap-proach. For this, we developed a speciated NMVOC emission inventory for Spain from 2010 to 2019 combining na-tional 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, sty-rene, n-butane, and cyclopentane, which together are responsible for 54 % of the total OFP. Our trend analysis indi-cates 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.

Automated summary

Ozone pollution is a persistent problem in Spain, and understanding the emissions and trends of Non-Methane Volatile Organic Compounds (NMVOC) is crucial for effective control strategies. A speciated NMVOC emission inventory for Spain from 2010 to 2019 revealed that paint manufacturing, manure management, and domestic solvent use were the main contributors to Ozone formation potential (OFP). The top 10 NMVOC species responsible for OFP were identified, and a reduction in NMVOC emissions and OFP was observed between 2010 and 2019, with a larger decrease driven by paint application industries and the road transport sector. However, an increase in OFP from the public electricity sector is expected by 2030 due to the planned increase in biomass use.