Atmospheric particulate matter 1 Comparative studies 1 Ecological response 1 Ecotoxicity 1 European Union 1 Heavy metals 1 Herbaceous plants 1 OECD 1 Particles (particulate matter) 1 Peroxidase (POD) 1 Plants (botany) 1 Point contacts 1 Polyaromatic hydrocarbons Roadside community 1 Roadsides 1 Species specifics 1 Terrestrial plants 1 Vegetative vigour test 1 atmospheric pollution 1 chlorophyll a 1 herb 1 particulate matter 1 phytotoxicity 1 reactive oxygen species 1 roadside environment 1