The overarching goal of this conference is to assess the impact of mismanaged plastic waste and nano- and microplastics litter on freshwater and terrestrial systems. We will explore how synthetic polymers and plastics are currently used, how waste is managed, and how these materials will enter into and affect natural and engineered ecosystems. We will address the concerns related to the effects of increased plastics usage in terms of the sources, fluxes and accumulation of nano- and microplastics. The key topics that will be introduced by well-established experts in the field include:

Synthetic polymers and microplastics: innovation vs. risks

Synthetic polymers and plastics are used for their unique properties and functionality as well as their low-cost price point. Many plastics are produced at large scales, but others represent specialized products such as bioinspired materials, targeting specific applications. What tradeoffs exist between plastic usage and environmental effects? How might regulations restricting plastic usage affect industrial production of larger scale plastics – and would these changes be beneficial for the environment? We will explore these questions at the beginning of the conference to frame the production, use and management of plastic as well as at the end of the conference to explore reformulations of plastic (e.g. biodegradable plastic) and alternatives in given case studies.

Sources and fluxes

The environmental release of incidentally produced particulate plastic from aging of mismanaged plastic waste dominates the direct release of plastic from consumer materials. However, degradation rates of macroplastic and release mechanisms of microplastics from products are poorly understood and the characteristics of the released plastic fragments remain very vague. Mass flow models can help to estimate the extent to which plastic particles are transported within and through different technical and environmental compartments. In this session, we will take stock of waste management practices, identify the most important point sources of plastics in the environment and discuss the use and the degradation of plastics under environmental conditions.

Developments and Challenges of Analytical and Sampling Methodologies

Due to the variability of synthetic polymers, their large polydispersity spanning over several orders of magnitude, and their relatively low environmental concentrations, (micro)plastics are very challenging to quantify in complex matrices. Furthermore, reference materials, standardized sampling methods or sample preparation protocols are currently lacking. We will discuss novel analytical techniques and innovative sampling and sample preparation approaches, which will be beneficial to the whole community working on particulate plastics.  We hope to stimulate cross-disciplinary knowledge exchange by in-depth discussion between scientist specialized in different topics.

Freshwater systems

Recent reports document that considerable amounts of microplastics have been detected in freshwater systems, such as lakes and rivers. It is hypothesized that microplastics detected in oceans dominantly originate form land based sources. In this session, we will focus on transport pathways of particulate plastics and factors which influence particulate plastic fate in freshwater environments. We will discuss aggregation kinetics of under different environmental conditions, assess sedimentation rates of aged plastic particles (including biofouling), and evaluate fluxes from rivers to the ocean. Engineered systems, including drinking water treatment plants which rely on healthy freshwater bodies, or waste water treatment plants, which stand at the interface between natural and technical environments, will also be covered in this session.

Terrestrial and agricultural systems

Data relating to particulate plastics in soils are progressively emerging since it has become evident that the terrestrial compartment represents one of the largest environmental sinks for (particulate) plastic. Agricultural soils are often in the focus as soil quality is essential to crop vitality and yield. Significant influxes of plastics into agricultural fields are anticipated both from the use of mulch films and from the application of microplastic-containing sewage sludge and biogas digestate. In this session, we invite contributions focusing on fate and transport of plastics in unsaturated and saturated porous media, specific degradation mechanisms for plastic in soils, and potential effects of (micro)plastic on soil ecosystem services.

Plastics across ecosystem boundaries

The study of plastic in the environment does not always fit neatly into the study of one ecological compartment alone. In this session, we specifically will address the changes plastics may undergo along their life-cycle, the fluxes of plastic across ecosystem boundaries, and address specific challenges researchers face when conducting complex experiments such as in mesocosms.

Interaction with biota and humans

Assessment of the risks associated with the increasing amount of particulate plastics accumulating in the environment requires both data on the exposure and hazards which these materials may pose. In recent years, the interactions of microplastics with biota ranging from single cell organisms, such as algae, to larger organisms from all trophic levels have been studied. Ultimately, potential impacts on human health drives the concerns from many stakeholders, especially the public. In this session, we address the hazards which particulate plastics may pose to both environmental and human health.