Plastics have been instrumental in providing innovative solutions to society, owing to their versatility, durability, and adaptability. As a result, plastic manufacturing has seen an exponential increase, with global production reaching almost 390 million tons in 2021 (57 million tons in Europe). This surge in plastic production has led to the proliferation of micro- and nanoplastics, which are small plastic particles generally less than 5 millimetres in size. These particles originate from various sources like cigarette filters, textile fibres, cleaning products, personal care items, and also from tyre wear and weathered plastic products. Unfortunately, their small size and persistence have resulted in their widespread presence in land, water, food, and air, posing significant environmental risks and potential threats to human health. The European Commission (EC) has responded to this pollution and health challenge through key policy documents like the Green Deal and the European Strategy for Plastics. Although there has been considerable research on the presence of microplastics in soil, water, and food, their occurrence in the air, both indoors and outdoors, has not been given sufficient attention so far. Limited data exists on the quantitative characterization of microplastics in urban and non-urban atmospheres, but this data is growing. However, the atmospheric emission rates from specific materials, actions, and environments are largely unknown at present. Furthermore, there is a scarcity of data regarding particles smaller than 3 µm, which are specifically those capable of reaching deep into the lungs. The introduction of regulatory instruments must be rooted in scientific evidence, and effective monitoring tools are required to assess their implementation and impact. Currently, the absence of fit-for-purpose technologies and harmonised methods is hindering progress in this regard. This report addresses some of these challenges, which are pivotal for a precise evaluation of the presence of micro- and nanoplastics and their potential impact on health and the environment. It aims to systematically review and evaluate the available published literature on methodologies used to measure primarily micro-plastic (to a lower extent also nanoplastic) in the air as well as their sources and transport.