Biodegradation: Biological process of organic matter, which is completely or partially converted to water, CO2/methane, energy and new biomass by microorganisms (bacteria and fungi).

Degradation: The partial or complete breakdown of a polymer as a result of e.g. UV radiation, oxygen attack, biological attack. This implies alteration of the properties, such as discolouration, surface cracking, and fragmentation

End of Life Tyre (ELT): A tyre that can no longer serve its original purpose (including on a passenger car, truck, two-wheel, airplanes, as well as off-road tires). This excludes used tyres that are retreaded, reused, or exported in used cars.

Microplastics: Solid synthetic polymer particulates with a size < 5 mm.

Nanoplastics: Solid synthetic polymer particulates with a size < 1 or < 100 µm

Non-exhaust emissions: Non-exhaust emissions are particle emissions from road traffic consist of airborne particulate matter (PM) generated by the wearing down of brakes, clutches, tyres and road surfaces, as well as by the suspension of road dust.

Primary/secondary microplastics: Primary microplastics are manufactured at the micro scale to be used in particular applications.

Secondary microplastics stem from the fragmentation of larger plastics

River catchment area: A catchment area is any area of land from which precipitation waters flow into a river.

Road dust: Road dust is composed of all particles found on a road. It may consist of particles from road wear (road surfacing and markings), vehicle wear (e.g. brake pads, tyres, and studs), vehicle emissions, atmospheric deposition, and other particles, including organic materials from nearby vegetation that settle on the road.

Road runoff: The portion of precipitation which flows from road surfaces

Rubber granulate: Rubber particles generally manufactured from ELTs as well as from rubber derived from other sources (e.g. virgin elastomer alternatives such as EPDM rubber and TPE), intended to be used in a variety of industrial applications.

Stormwater runoff: Precipitation that flows over the ground, usually also transporting pollutants deposited on surfaces.

Toxicity: Inherent property of being poisonous or harmful to plant, animal or human life

Tyre and Road Wear Particles: Particles emitted due to the friction occurring between the vehicle tyres and the road surface, during normal use of tyres. These are composed of a mixture of tyre tread material (e.g. synthetic and natural rubber, silica, oil, carbon black, sulphur compounds, zinc oxide) and road pavement material. Other mineral particles originating from road surfaces or contained in road dust may be present in samples collected in the environment.

Tyre tread: The portion of the tyre that comes in contact with the road surface.

Value chain: A very large-scale business process that results in the delivery of a process or service to a customer.

Waste mismanagement: Waste that is either littered or inadequately disposed of.

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