Influence of Volatile Organic Compounds Emissions from Road Marking Paints on Ground-level Ozone Formation: Case Study of Kraków, Poland

Abstract

Ground-level ozone, worldwide recognised amongst key pollutants responsible for smog and a significant pulmonary irritant is formed in troposphere via a photolytic process from nitrogen oxides (NOx). Volatile Organic Compounds (VOC) during their decomposition in the atmosphere interact with NOx and thus affect ozone formation. Their interactions are not equal and have been quantified in Maximum Incremental Reactivities (MIR). Using MIR, calculated was ozone formation potential of VOCs emitted from an aromatic solvent-containing paint that is used for marking of roads in Kraków, Poland. To simulate possible environmental benefits of using alternative materials, analysis was then extended to model paint without aromatic solvent and a waterborne paint.Ozone formation potential of the road marking paint currently used as standard in Kraków was calculated to be more than twice the amount of VOCs it emits: 240kg of solvents evaporating from one tonne of paint might cause formation of over 550kg of ozone – in Kraków that means up to 42 tonnes of tropospheric ozone annually. Elimination of the aromatic solvent would not lead to lesser VOC emissions, but decrease ozone production capability by about 50%. Further reductions could be realised with waterborne paint – VOC emissions lowered by 79% and potentially formed ozone reduced by up to 93%.A cradle-to-grave Life Cycle Assessment (LCA) performed on the three analysed paints demonstrated that durability is the main environmental impact factor. Assuming service life achieved at our test field, where modern waterborne paints applied at 600μm wet film and reflectorised with properly selected high-performance glass beads complied with the specification for two years, they definitely are more sustainable choices as compared to solventborne materials.Quantification of the effect of produced ozone on health was beyond the scope of this work, but based on literature reports a measureable effect is anticipated due to a well-documented correlation between increased tropospheric ozone level and increased mortality and morbidity.