Plastic occurrence in fish caught in the highly industrialized Gulf of İzmit (Eastern Sea of Marmara, Türkiye)

Microplastic contamination in some beverages marketed in türkiye: Characteristics, dietary exposure and risk assessment

In this study, microplastic contamination in water, natural mineral water and mineral water, sparkling soft drinks, cold tea and some traditional beverages marketed in Türkiye were assessed. Microplastics physically and chemically characterized by microscope and ATR/FT-IR, respectively. Microplastics were detected in 9 out of 47 beverage samples. A total of 250 microplastics with 5 different polymers, 2 different shapes, and 7 different colours were detected in 47 beverage samples. The average microplastic concentration was 2.24 ± 9.86 particles/L for all beverages analysed. The highest average microplastic concentration was found in mineral waters in glass bottles (average 11.3 particles/L). No microplastics were found in cold tea and other drinks. The total annual microplastic exposure from beverage consumption in male and female individuals aged >15 years was 2029 and 1786 particles/mL/year, respectively. The microplastic load index category of all beverage samples was determined as "moderate". The average pRi level of all beverages was 117 ± 260 and the risk level was determined as "low". The study provides evidence that microplastics are common in beverages and that microplastics are directly ingested by humans.

Microplastic pollution in wild and aquacultured Mediterranean mussels from the Sea of Marmara: Abundance, characteristics, and health risk estimations

Microplastic (MP) pollution raises urgent concerns about the environmental well-being and the safety of the food supply for humans. Mussels are essential filter-feeding organisms that may be highly susceptible to MPs uptake due to their global distribution and sedentary lifestyle. There is also a knowledge gap regarding MP levels in commercially-farmed and wild-sourced mussels for human consumption, creating gaps in risk identification for food safety. This study aims to fill this gap in understanding by (a) investigating the presence and abundance of MPs in both wild and aquacultured mussels collected from six different stations in the Sea of Marmara, (b) comparing the levels of MPs between aquacultured and wild mussels, and (c) evaluating the potential health risks associated with the consumption of these contaminated mussels. Polymer types were verified by ATR-FTIR (Attenuated Total Reflectance Fourier Transform- Infrared Spectroscopy), and 6 different polymers have been identified. Among the total 753 identified MPs, the majority (79.8%) were fibers, with the predominant size range (42.4%) falling between 0.1 and 0.5 mm. Consuming wild mussels was associated with a 187.6% higher risk of MP intake compared to aquaculture. A consumer can potentially be exposed to 133.11 to 844.86 MP particles when consuming a 100 g serving of mussels, with risks becoming more significant as portion sizes increase, as is the case in some countries where portions reach 225 g. In this study, detailed information is presented on MP pollution in both wild and aquacultured mussels from Sea of Marmara, providing valuable insights for ensuring food safety, effective management and control of MP pollution in this region.

Exposure to bisphenol A and fiber-type microplastics induce oxidative stress and cell damage in disk abalone Haliotis discus hannai: Bioaccumulation and toxicity

Along with environmental pollution caused by rapid economic development and industrialization, plastic waste is emerging as a global concern in relation to marine ecosystems and human health. Among the microplastics, fiber-type microfibers (MF) and bisphenol A (BPA), which are widely used as plasticizers, do not decompose well in the ocean, and tend to accumulate in organisms, generating an increased oxidative stress response. This study investigated the abalones' antioxidant and cell death responses following exposure to the environmental pollutants MF and BPA. Levels of malondialdehyde (MDA) and DNA damage increased over time, demonstrating the degree of lipid peroxidation and DNA damage in abalones exposed to individual and combined environmental conditions of MF and BPA. Compared to the single MF and BPA exposure groups, the combined exposure group showed a higher expression of antioxidant enzymes. A similar pattern was seen in the expression of the apoptosis enzyme caspase-3. Both MF and BPA caused oxidative stress and antioxidant enzymes were expressed to alleviate it, but it is believed that cell damage occurred because the stress level exceeded the allowed range.

Spatiotemporal distribution of microplastics in true frogs (Ranidae:Pelophylax) populations from Türkiye

Microplastics (MPs), which are of increasing concern in almost all ecosystems, continue to be an environmental threat. In the present study, the presence of MPs is investigated by using the gastrointestinal tracts (GITs) obtained from the true frog individuals sampled in the past years. The sample consists of a total of 146 individuals obtained from various regions of Türkiye. The results show that MPs were found in 87 adult frog individuals. The most predominant shape of MPs found was fiber, with a predominance of transparent color, and ethylene-vinyl acetate (EVA) was also the most abundant microplastic material. The highest amount of MPs among adult frog populations were found in the Denizli province. The size of MPs ranged between a minimum of 66 and a maximum of 3770 μm. In addition, no relationship was found between the body length and weight of the frogs and the sizes of MPs. Historically, most MPs were found in samples from 1990 and the highest content in terms of both color and material was detected in 1990. MPs were detected in almost all the years studied, but microplastic abundance varied from year to year. These results can be explained by the number of samples, habitat, and feeding behavior of adult frogs.