Projects - JN (Julia) Möller

COMP-L - Compostable Microplastics and Leachates

Studying the fate and effects of compostable plastic products under realistic conditions

Compostable plastic products are commonly perceived as an environmentally friendly alternative to conventional plastics. However, European standard tests used to certify a material as compostable do not reflect realistic conditions in municipal composting facilities. Studies have shown that high numbers of microplastics (< 1 mm) derived from compostable plastic products remain in the compost and may have a higher resistance to enzymatic degradation than previously assumed. The compost, including residual microplastics, is then spread onto agricultural fields and incorporated in the soil. To date, there are no studies showing if these microplastics degrade in an appropriate time frame under field conditions, or if they accumulate due to repeated compost application, with potential negative effects on overall soil health and crop production.
Furthermore, it has been shown that compostable plastic products contain additives and non-intentionally added substances (so-called NIAS) - chemicals that can leach from the product during the use phase and at the latest during the composting phase. Negative effects of these leachates have been reported for aquatic organisms, but studies concerning the effects on soil dwelling organisms and plant growth are lacking.
EU-legislation currently does not regulate the use of compostable plastic products, but policy makers have called for scientifically based information on the sustainability of compostable plastic products for future legislations. Thus, COMP-L aims to assess:

1) If residual microplastics derived from (already composted) compostable plastic products degrade in mesocosms under field conditions within two years.

2) How residual microplastics and chemical leachate from compostable plastic products affect plant health and crop production by assessing various plant health related endpoints in phytotoxicity tests on the common bean.

3) How chemical leachate from compostable plastic products affects earthworm fitness, reproduction and juvenile development

This is a Veni Project funded in the scope of the NWO Talent Programme

Duration of Project: September 2024 - September 2027

Previous Projects:

MiKoBo (Germany) - Microplastics in compost and soils

BabbA (Germany) - Fate of biodegradable plastic bags in composting plants

Ongoing Projects:

MINAGRIS (EU, Netherlands)- Microplastic occurence and effects on agricultural soils