Available online since June 25, 2022, various Imptox scientists from Europe and South Korea collaborated to understand the accumulation of microplastics in Manila clams.

Microplastics in marine animals and the ingestion of those particles by humans via the food chain are becoming an emerging concern.  Imptox researchers and advisory board members from Ghent University, Sciensano, the University of Belgrade, the Korea Institute of Analytical Science and Technology, the University of Vienna and the Serbian Academy of Sciences and Arts participated to better understand microplastics accumulation in differently sized Manila clams from South Korea.

For that purpose, they measured microplastics in small and large Manila clams, using Nile red staining and μFTIR imaging. They found that microplastics accumulation was not affected either by the size or the age of the clams. Their research was presented in the article entitled “Comparative profiling and exposure assessment of microplastics in differently sized Manila clams from South Korea by μFTIR and Nile Red staining” and published in the Marine Pollution Bulletin.

Imptox scientists and contributing authors: Maria Krishnade Guzman, Mirjana Andjelković, Vesna Jovanović, Jaehak Jung, Lea Ann Dailey, Andreja Rajković, Tanja Ćirković Veličković

Further authors: Juyang Kim, Bruno De Meulenaer

Marine Pollution Bulletin, June 2022

https://doi.org/10.1016/j.marpolbul.2022.113846

Comparative profiling and exposure assessment of microplastics in differently sized Manila clams from South Korea by μFTIR and Nile Red staining

Abstract:

The accumulation of microplastics in marine organisms is an emerging concern. Due to trophic transfer, the safety of seafood is under investigation in view of the potential negative effects of microplastics on human health. In this study, market samples of Manila clams (Ruditapes philippinarum) from South Korea were segregated into two groups of considerably different size (p < 0.05), namely small clams with shell length of 40.69 ± 3.97 mm, and large clams of shell length 51.19 ± 2.86 mm. Comparative profiling of the number, size, shape, and polymer type of microplastics were performed using μFTIR imaging and Nile red staining. Overall, μFTIR detected only 1559 microplastics while 1996 microplastics were counted based on staining from 61 Manila clams (30 small and 31 large), leading to an overestimation of 18 to 75 %. Comparable microplastics concentration, based on μFTIR, were observed at 2.70 ± 1.66 MP/g or 15.64 ± 9.25 MP/individual for the small samples, and 3.65 ± 1.59 MP/g or 41.63 ± 16.90 MP/individual for the large ones (p > 0.05). Particle diameters of 20–100 μm was the most dominant, accounting for 44.6 % and 46.5 % of all microplastics from the small and large groups, respectively. Particles, with a circularity (resemblance to a circle) value between 0.6 and 1.0, were the most prevalent, followed by fragments and fibers. At least 50 % of microplastics from the small and large samples were polystyrene, making it the most abundant polymer type. Despite the substantial difference in the size of the animals, only a weak to moderate correlation was observed between microplastics content and the physical attributes of the clams such as shell length and weight, (soft) tissue weight, and total weight (Spearman's coefficient < 0.5). The estimated intake of microplastics by the Korean population was 1232 MP/person/year via small clams, 1663 MP/person/year via large clams, and 1489 MP/person/year via clams independent of size.