Supervisor: Karl Ljung, Department of Geology, karl.ljung@geol.lu.se

The total global supply of plastic pollution to the world’s oceans amounted to between 4.8 and 12.7 million metric tons in 2010 (Jambeck et al., 2015). In the ocean, plastic is successively broken down into smaller and smaller pieces and finally ends up as microplastic. Microplastic pollution has been found in all oceans and all parts of the ocean, including in the high arctic and in sediments retrieved from the deepest ocean basins. The negative environmental effects of microplastic particles are of great concern because they can enter the food webs and have diverse detrimental effects on organisms’ health. Microplastics also enter humans through food and drink, and microplastics have been found in such diverse foods and beverages as beer, fruit, shellfish and sea salt (Blackburn and Green, 2022).

Microplastic is concentrated in sea salts because of the production process that involves evaporating large amounts of seawater, and salt is one important source of microplastics in humans. It has also been shown that the concentrations of microplastics in sea salts track ocean pollution levels well and can potentially be a way of monitoring ocean plastic pollution levels (Kim et al., 2018).

In this project, we will measure microplastic concentrations in natural salts from Denmark, Norway and Iceland. We will target one brand of salt produced from groundwater (Læsø salt https://www.laesoesalt.com/en/), and three salts produced from ocean water (Norður Salt https://nordurco.com/, Saltverk https://saltverk.com/, North Sea Salt Works https://www.northseasaltworks.no/?lang=en_us). The microplastic concentrations in these brands will be used to assess the marine pollution levels and significance for human exposure to microplastics.

Quantification of microplastic concentrations will be done by dissolving the salt and filtering out the microplastic particles. Identification and quantification of microplastic particles will be done under the microscope (Kim et al., 2018). During the project we will also investigate the possibility to identify the type of plastic by means of spectroscopy (i.e. FTIR), but no detailed plans for this has been done yet.

The project will add important quantification of microplastic in a product for human consumption and add knowledge on the levels of microplastic pollution in the North Atlantic and North Sea.

The project suits you who wants to work in a laboratory, like microscopy and want to work with a research question concerning plastic pollution and the potential human health effects.

References

Blackburn, K., Green, D., 2022. The potential effects of microplastics on human health: What is known and what is unknown. Ambio 51, 518–530. https://doi.org/10.1007/s13280-021-01589-9

Jambeck, J.R., Geyer, R., Wilcox, C., Siegler, T.R., Perryman, M., Andrady, A., Narayan, R., Law, K.L., 2015. Plastic waste inputs from land into the ocean. Science 347, 768–771. https://doi.org/10.1126/science.1260352

Kim, J.-S., Lee, H.-J., Kim, S.-K., Kim, H.-J., 2018. Global Pattern of Microplastics (MPs) in Commercial Food-Grade Salts: Sea Salt as an Indicator of Seawater MP Pollution. Environ. Sci. Technol. 52, 12819–12828. https://doi.org/10.1021/acs.est.8b04180

Uppdaterat: Nina Reistad | 2022-11-28