Numerous studies have identified tyre abrasion as the leading cause of microplastics emissions into the environment, far outweighing other sources such as manufacturing resin, washing of synthetic clothing, and fishing gear.[1] Globally, it is estimated that tyres leak around 1.5 million tonnes of microplastics each year.[2] Because of the currently limited opportunities to capture microplastics from tyres, these are also predicted to be the largest source of microplastics entering the aquatic environment.

… tyre abrasion is the leading cause of microplastics emissions into the environment, far outweighing other sources such as manufacturing resin, washing of synthetic clothing, and fishing gear

In a report prepared for the European Commission, Eunomia estimated the cost-effectiveness of different methods to prevent microplastics from tyres entering the environment.

The study considered:

  • Development of a standard measure of tyre tread abrasion rate as a pre-requisite to
    1. Including tyre tread abrasion rates on the tyre label to inform consumer choices, or
    2. Using regulation for tyre tread abrasion to restrict the worst performing types from the market.

The study concluded that restricting certain types of tyres from the market alone, or in combination with labelling measures, were relatively cost-effective ways to prevent emissions at source. However, estimates suggested that even the most effective measure would at most reduce microplastics from tyres reaching surface water by 33%. Further capture systems would be needed to prevent tyre microplastics entering waterways, but the costs of this were not estimated in this study.

The findings from this study could be used to prioritise policy measures that will reduce microplastics from tyres entering the environment in Aotearoa New Zealand.

References
[1] Ryberg et al., “Global Environmental Losses of Plastics across Their Value Chains,” Resources, Conservation and Recycling 151 (2019) Sutton, “Understanding Microplastic Levels, Pathways, and Transport in the San Francisco Bay Region”, 2019

[2] Ryberg et al., “Global Environmental Losses of Plastics across Their Value Chains”

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