Abstract

In recent years, the problem of tiny plastic particles, or microplastics, in the environment has attracted considerable attention. Microplastics degrade slowly, if at all, and are found everywhere around us. Not much is known about microplastics in air inside homes. The Ministry of Infrastructure and Water Management (IenW) would very much like to know more about this because small particles of certain substances are detrimental to air quality and consequently to public health.

RIVM has therefore looked into the possible presence of microplastics in indoor air and has summarised the knowledge found in scientific literature on this topic. This knowledge will enable IenW to take any measures that may be necessary. It can also be used to assess whether these substances entail health risks and the data needed to make such assessments.

Generally speaking, the concentrations appear to be low. On average, there are between 1.6 and 9.3 microplastic particles per cubic metre. The particles measured are fairly large, i.e. more than 11 micrometres in diameter. This makes them larger than the ultrafine particles normally measured to assess air quality (PM2.5 and PM10 or smaller than 2.5 and 10 micrometres in diameter). It is possible that much smaller microplastics are also present in the investigated homes. But it is currently difficult to measure the smaller types of microplastic particles in air. It is precisely smaller particles that are not good for air quality (e.g. PM2.5 and PM10).

The most significant sources of microplastics in homes are textiles, such as clothing, carpets and curtains. Besides fibres, many fragments of microplastics are found in indoor air. Further research is needed to determine whether these particles also originate from textile fibres or from other sources. Besides this, information is needed on the smallest type of microplastic particles. With this knowledge more effective measures can be taken to improve air quality.