First report of quantification and classification of buried litter on the public beaches around the Sea of Marmara, Turkey

Differential scanning calorimetry (DSC): An important tool for polymer identification and characterization of plastic marine debris

Differential scanning calorimetry (DSC), a routine thermoanalytical method in material science, is gaining utility in plastic pollution research to improve polymer identification. We optimized a DSC method, experimentally testing pan types, temperature ramps, number of melts, and minimum sample masses. Using the optimized method, we created an in-house thermogram library from 201 polymer reference standards. We determined peak melting temperature cutoffs for differentiating variants of PE and nylon. PE cutoffs remained stable after experimentally weathering standards outdoors or for severely weathered HDPE debris found on Hawaii's beaches. Marine debris samples, across a range of weathering severity and previously identified as either low-density or high-density polyethylene (LDPE or HDPE) based on the 1377 cm-1 peak indicating methyl groups by attenuated total reflectance Fourier-transform infrared spectroscopy (ATR-FTIR), were analyzed by DSC to confirm or challenge the ATR-FTIR PE differentiation. ATR-FTIR was correct for >80% of the HDPE samples, but <40% of those initially identified as LDPE by ATR-FTIR. Accuracy did not relate to weathering extent. Most samples mis-identified as LDPE were HDPE that had formed methyl groups likely from chain scission during photooxidation. ATR-FTIR alone is unreliable for differentiating weathered PE, DSC is required. We provide a multiple-method workflow for complete and accurate polymer identification, even for microplastics ≥0.03 mg. Applying these methods can better identify the polymer composition of marine debris, essential for sourcing and recycling efforts.

A characterization and an exposure risk assessment of microplastics in settled house floor dust in Istanbul, Turkey

The presence of microplastics in the indoor environment presents growing environmental and human health risks because of their physicochemical and toxic characteristics. Therefore, we aimed to isolate, identify, and characterize plastic debris in settled house floor dusts. This study is a rare study which assess the risks of plastic debris in settled house dust through multiple approaches including the estimated daily intake, pollution loading index, and polymer hazard index. The results indicated that polyethylene and polypropylene were the predominate polymer type of plastic debris in settled house dust with various shapes and colors. The risk assessment results also indicated the serious impact of microplastics in terms of extremely dangerous contamination as well as the fact that they present a polymer hazard. Results indicated that humans have a higher risk of exposure to microplastics via ingestion rather than inhalation. In addition, infants had a higher risk of potential intake compared to other age groups.

Macro- and microplastic abundance from recreational beaches along the South Aegean Sea (Türkiye)

This study aimed to evaluate the abundance and diversity of macro- and microplastics in sand samples collected during summer and winter from eight different beaches used for recreational purposes located on the South Aegean coasts of Türkiye. According to the results, microplastic in fiber shape was dominant on all the beaches. The highest microplastic abundance was determined at Ölüdeniz Kumburnu Beach (360.00 ± 237.66 particles kg-1 dw) in summer and at Aktur Beach (358.33 ± 397.24 particles kg-1 dw) in winter. A significant positive correlation was found in the winter between microplastic amounts and wind speed. The study area is an important touristic center faraway from major cities and industrial areas. Thus, plastic pollution in this area may be the result of tourism activities in the summer, discharge waters from wastewater treatment plants or transportation by meteorological factors (like waves, wind or river flows).

Plastic debris, persistent organic pollutants and their toxicity impacts in coastal areas in Central Chile

The chemical components of plastic wastes have made their disposal a major economic, social, and environmental problem worldwide. This study evaluated the acute toxicity and genotoxicity of marine plastic debris on the beaches of Concepción Bay, Central Chile, taken during three periods (spring, summer, and winter). An integrated approach was used, including chemical and toxicological data, using the Microtox® test with Vibrio fischeri and SOS chromotest with Escherichia coli and concentrations of polychlorinated biphenyls (PCBs), Organochlorine Pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs). The results presented here exclusively include the novel data obtained from the winter campaign, revealing high concentrations of PBDEs (238 ± 521 ng g-1). In addition, the genotoxicity and acute toxicity tests were sensitive for most of the samples studied. This investigation is the first attempt to analyse the toxicity of plastic debris in coastal areas along the Chilean coast.

Changes in Sources and Composition of Beach Waste in Coastal Cities around the Bohai Sea of China during the Tourist Peak and Off-Peak Seasons

Beach waste is an important pollutant in the Bohai Sea and coastal cities around the Bohai Sea and has raised many social and environmental concerns in China. The semi-closed characteristics of the Bohai Sea, the well-developed tourism, the special industrial structure and residents' living habits endow the beach waste around Bohai sea with a unique character that should be explored. This study investigated changes in the sources and composition of beach waste in coastal cities around the Bohai Sea of China during the tourist peak and off-peak seasons. Beach waste from twenty beaches in thirteen coastal cities around the Bohai Sea was sampled and analyzed in March and August 2021, respectively. The results showed that beach waste around the Bohai Sea was characterized by large quantities and small weights and was greatly affected by human coastal activities. The sources and composition of beach waste from different coasts and different seasons varied, whereas the overall trend was consistent. In terms of composition, beach waste in both the tourist peak season and off-peak season was mainly composed of plastics, fabrics and paper, which accounted for more than 70% of the total in weight. Meanwhile, the proportion of plastics in the total quantity of beach waste was greatest (maximum of up to 71%) and exhibited seasonal fluctuations, trending higher in the tourist peak season than in the off-peak season. In contrast, trends in the proportion of paper and fabrics in the total quantity and total weight of beach waste were relatively stable in different seasons. In terms of sources, beach waste mainly derived from human coastal activities, the proportion of which in the total quantity of beach waste in the tourist peak season reached 70.55% and was 11% higher than that in the tourist off-peak season. Shipping/fishing activities were the second largest source of beach waste, and their proportion in the total quantity of beach waste in the tourist peak season was 5% lower than that in the tourist off-peak season, as the tourist peak season around the Bohai Sea coincides exactly with the fishing moratorium. The quantity of smoking-related waste only accounted for 9.35% and 7.73% of beach waste in the tourist peak and off-peak seasons, respectively. The special semi-enclosed structure of the Bohai gulf, surrounded by land on three sides, aggravated the accumulation of beach waste on the coast. Source reduction and classified recovery, collaborative management of marine waste and beach waste, and joint prevention and control mechanisms of three provinces (Liaoning, Hebei and Shandong) and one municipality (Tianjin) were suggested for comprehensive management of beach waste in coastal cities around the Bohai Sea of China. This study provided valuable information for beach waste management in coastal cities around the Bohai Sea of China.

Beach debris quantity and composition around the world: A bibliometric and systematic review

Anthropogenic pollution of marine ecosystems caused by beach debris has become a serious environmental concern in the last few decades. Regarding the raising production of beach debris, the present work aimed to summarize the quantity and quality of beach debris reported from different beach areas of the world. Also, a bibliometric analysis was used to analyze research trends and upgrade knowledge in this research area. Using Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA), the eligible papers reviewed regarding beach debris abundance along with their composition from 2010, which were extracted from the Scopus database. The results of the study showed that plastic items represented the dominant material (61.25%), followed by food (5.88%), wood (5.78%), metals (5.2%), and glass (5%). Further, the beaches studied were classified into three degrees, including highly polluted (31.5 items/m2), moderate polluted (3.47 items/m2), and low polluted (0.37 items/m2), based on the average abundance of debris.

A review of plastic pollution in aquatic ecosystems of Turkey

Turkey is one of the major plastic pollution sources in the Mediterranean and the Black Sea. This review summarizes present information, data, and legislation on plastic pollution in Turkish aquatic ecosystems. According to results derived from reviewed studies, both macro- and microplastic pollutions were documented in Turkish aquatic ecosystems. Most of the studies on plastic pollution in Turkish waters were performed in the marine environment while only four were conducted in freshwater environments. Spatially, the majority of these studies, which were on levels in the marine environment, were conducted on the northeastern Mediterranean coasts of Turkey, especially Iskenderun and Mersin Bays. Additional studies were carried out on either the ingestion/presence/impact of microplastics by/to aquatic organisms or the entanglement of marine organisms in plastics. There were also studies assessing the microplastic content of commercial salt, and another has reported microplastic presence in traditional stuffed mussels sold in Turkish streets. Some studies were conducted on microplastic presence and/or their removal in wastewater treatment plants in Mersin, Adana, Mugla, and Istanbul cities. Macro- and microliter loading from a few Turkish rivers to the sea was also estimated. All these investigations indicate that Turkish aquatic environments have significant plastic pollution problems, which were also underlined by the legislative studies. The need for further studies in this field still exists, especially in freshwater environments.

Is coastal erosion a source of marine litter pollution? Evidence of coastal dunes being a reservoir of plastics

This baseline reports scientific evidence of marine litter items embedded in the dune volume at two study sites on the North Atlantic Portuguese coast. We described how stranded litter participate in the sand dune growth/erosion processes on a natural beach-dune system. From the storm-eroded foredunes on the urbanized beach, we documented exhumed plastics with age up to 38 years. Whether litter burial was due to beach-dune morphodynamic processes, or to irresponsible and/or illegal dumping in the past, this work emphasises the need of improving buried litter census and monitoring on coastal dunes. Coastal erosion processes may further exhume litter buried in dune volumes and on other coastal environments over short- and long-term, re-exposing items into the marine environment. Thus, coastal erosion can be accounted as a secondary diffuse source of littering pollution, beside the multiple sources already identified in the environment.

A seasonal comparison of litter impacts along the Viña del Mar - Concón coastal strip, Valparaiso region of Chile

The Vina del Mar - Concón Coastal strip is well known for its urban beaches, which play an essential role in the national economy. With extreme urban development, these beaches have become more polluted by litter. This paper evaluates the abundance, spatio-temporal distribution, typology, and sources of beach litter in 14 sectors located inside this coastal strip. A total of 19,886 litter items were collected and grouped into 50 different categories (11 litter typologies). Overall average litter abundance was 0.21 items/m² while during the fall and winter averages were 0.25 items/m² and 0.17 items/m². Values changed along the area and between seasons. Plastics, cigarette butts and paper-cardboard typologies dominated the samples with 42% (0.088 items/m²), 25.4% (0.053 items/m²) and 20.8% (0.043 items/m²).

Quantifying plastics waste accumulations on coastal tourism sites in Zanzibar, Tanzania

Plastic pollution is becoming a growing concern on coastal tourism sites. Unquantified amounts of plastic materials are discharged into coastal waters with detrimental effects on local marine environments. With the expansion of the tourism industry, waste increasingly originates from tourism activities and ends up into the ocean due to poor management of solid waste post-consumption. This study explores the sources, abundance, and type of litter in Zanzibar, Tanzania by surveying four coastal tourism sites. The analysis illustrates the contributions to plastic pollution of four sectors of Zanzibar's economy (residential households, building and construction, tourism, and commercial sector). Findings suggest that plastic accounted for almost half (48.5%) of the waste inflow to the environment, and single-use packaging was the dominant litter item on all sampled sites.