Extending the theory of planned behaviour to investigate the issue of microplastics in the marine environment

The attention to microplastics and the consequences of its presence in the marine environment is increasing in scientific fields as well as on common media channels. In the absence of regulation in many countries, manufacturers are not required to exclude microplastic from their products, however consumers could force the production in a more sustainable direction with their choices. This study demonstrates the utility of the Theory of Planned Behaviour (TPB) in understanding the publics' intention to avoid buying products which contain microplastics. All three TPB antecedents of intentions are important. The study, based on a sample of respondents in NSW (Australia), also reveals respondents' habitual behaviour of avoiding buying products containing microplastics strongly predicts their intended future behaviour. Last, modelling reveals direct and indirect means through which intentions to avoid buying microplastics can be increased, via increased environmental concerns and public knowledge and health concerns about microplastics.