New Publication: Citizen science project

We published a new paper on our citizen science project, and the work in the Netherlands and on the Lesser Antilles.

Figure 1

Figure showing sampling locations on project

Abstract: Microplastics (<5 mm) are contaminants of emerging global concern. They have received considerable attention in scientific research, resulting in an increased awareness of the issue among politicians and the general public. However, there has been significant variation in sampling and extraction procedures used to quantify microplastics levels. The difference in extraction procedures can especially impact study outcomes, making it difficult, and sometimes impossible, to directly compare results among studies. To address this, we recently developed a standard operating procedure (SOP) for sampling microplastics on beaches. We are now assessing regional and global variations in beach microplastics using this standardized approach for 2 research projects. Our first project involves the general public through citizen science. Participants collect sand samples from beaches using a basic protocol, and we subsequently extract and quantify microplastics in a central laboratory using the SOP. Presently, we have 80+ samples from around the world and expect this number to further increase. Second, we are conducting 2, in-depth, regional case studies: one along the Dutch coast (close to major rivers, a known source of microplastic input into marine systems), and the other on the Lesser Antilles in the Caribbean (in the proximity to a hotspot of plastics in the North Atlantic Ocean). In both projects, we use our new SOP to determine regional variation in microplastics, including differences in physicochemical characteristics such as size, shape, and polymer type. Our research will provide, for the first time, a systematic comparison on levels of microplastics on beaches at both a regional and global scale.

New Publication: Zebrafish and microplastics

We published new research on the uptake and effect of microplastics on zebrafish embryos and larvae. The main take home messages:

  • Zebrafish larvae exposed to PS particles had minimal biodistribution.
  • Internalized particles caused an immune response by activating the complement system.
  • Enriched toxicity pathways for lipid metabolism and oxidative stress were detected.
  • Our results can be used to develop Adverse Outcome Pathways for microplastics.


Figure showing uptake of polystyrene particles by neutrophils using fluorescence microscopy.

Visit from 8-10 year old “university students”

Recently we were visited by students from Transvaal University,  an enrichment programme for low-income children in Transvaal neighborhood in the city of The Hague. Transvaal University is an initiative of the primary school ‘Het Galjoen’ and  community centre ‘Boerenplein’ in the Transvaal district in The Hague.  Every Saturday morning a class of fifteen eager students are taught a variety of different (socially oriented) subjects in order to enhance the talents and skill-sets of these children. I gave a workshop on microplastic and plastic pollution in the aquatic systems, and linked it to possible effects on fish. As part of the class we dissected a fish with the kids, and discussed how plastics and other pollutants can cause harm to organisms.



Kids and plastics…

Together with kids aged 9-12 I conducted a beach clean-up Ameland, the Netherlands. Ameland is located in the north of the Netherlands, and is a scarcely populated area. The goal of the collection was to show them how much plastic can be found on a beach… even when it appears to be very clean when you look at the beach from a distance. We collected several garbage bags full of plastic (and other) waste within 30 minutes. Next we identified some of the plastics using a standardized guide.

We found, among other items, the following:

  • Shopping bags
  • Garbage bags
  • Drink bottles
  • Caps/lids
  • Pens
  • Beach toys
  • Straws
  • Ropes, strings and fibers
  • Nets
  • Fishing lines

We discussed how these plastics could impact the environment, including a paper on garbage in sperm whales, and the amount of “invisible”microplastics. A follow-up series of mini-lectures at school will focus in more depth about this issue… to be continued!

Paper published with optimized protocol for sampling and extracting microplastic from sand samples

Aiken Besley, a recent graduate from Leiden University College, managed to publish his work in the international journal Marine Pollution Bulletin.

His undergraduate research focused on standardizing extraction and sampling methods for microplatics on beaches. A range of studies have found significant levels of microplastics in beach sand. However, he highlighted that there is a considerable amount of methodological variability among these studies. This variation makes it difficult, and often impossible, to compare across studies, as there is no standard procedure for sampling or extraction of microplastics. He identified key variations in sampling and extraction procedures across the literature through a detailed review. He found that sampling depth, sampling location, number of repeat extractions, and settling times are the critical parameters of variation.

Next, using a case-study he determined whether and to what extent these differences impact study outcomes. By investigating the common practices identified in the literature with the case-study, he provides a standard operating procedure for sampling and extracting microplastics from beach sand.

The full article can be found here.

Aiken Besley in the lab working  on optimizing the extraction of microplastics from beaches