پديد آورندگان :
محمدي گلنگش، محسن دانشگاه گيلان صومعه سرا - دانشكده منابع طبيعي - گروه علوم و مهندسي محيط زيست , عچرش، علي دانشگاه گيلان صومعه سرا - دانشكده منابع طبيعي , صنعتي، علي محمد دانشگاه خليج فارس بوشهر - پژوهشكده خليج فارس - گروه محيط زيست
چكيده لاتين :
Background and Objectives: The abstract is one of the essential parts of a paper. The abstract must be presented on Plastic products have a growing trend due to ease of production, flexibility, strength, and economic efficiency. These products are used in various industries, including construction, automobiles, marine industries, aerospace, electricity and electronics, transportation, medicine and pharmaceuticals, cosmetics, paints, agriculture, home appliances, etc. It can be said that today, plastic has become a part of human life, and no one can claim that who doesn’t relate to plastic daily. This is illustrated that our environment is facing a massive amount of plastic pollution in the air, soil, and water. Also, this concern is exacerbated by the slow rate of degradation of these compounds in nature. The presence of compounds such as phthalates and bisphenols in the structure of plastics, which their carcinogenic effects and hormonal disorders have been reported in humans, can also intensify human concerns in public health and environmental issues. Scientists attempt to control the unbridled expansion of plastics in the environment by changes in the chemical structure of them into biodegradable forms, finding alternative products, and categorizing the primary sources of contamination. The largest enclosed water body of the Caspian Sea, with its unique sturgeon fish species and fragile ecological conditions, is one of the most important habitats. Due to the growing development trend in the surrounding countries of the Caspian Sea, microplastic pollution is increasing in this ecosystem. The present study was conducted on the southwestern shores of the Caspian Sea in the province of Guilan owing to the ecological importance of this habitat Methods: In this study, sampling of surface sediments from the southwestern coastlines of the Caspian Sea was performed at 13 stations in September and October 2016. About 3kg of Sediment samples were collected from the surface section of 0-5 cm at each station. After dewatering, the samples were dried at 60 ° C and then passed through a sieve with a 5 mm mesh for homogenization. A two-step extraction method based on density was done by two saturated solutions prepared from NaCl and NaI to separate the microplastics from the sediment samples. The number of fragments, shape, and color separation of microplastics was performed using the stereomicroscope. The Fourier transform infrared spectroscopy device was also used to identify the chemical structure of microplastics. Findings: A total of 909 microplastic fragments were obtained from sediment samples of the region. The results showed more microplastics in tourist and commercial centers such as Astara, Bandar Anzali, Caspian free zone, and areas of Chamkhaleh were more than other stations. Studies have demonstrated that in terms of shape, microplastics are separated into three categories, including filaments, disintegrating fragments, and membranes. The consequences of spectroscopy showed that the microplastics in the study area are composed of 4 different types of polymers: polyethylene, polypropylene, polyester, and polystyrene. The outcomes also displayed that the region's average microplastic particle size is 1.43 ± 1.06 mm. Conclusion: According to the results, commercial and tourist sectors have a significant role in spreading micro-plastics in the study area. The continued use of fishing nets and plastic ropes in the fishing industry are other sources of this type of pollution in the region. Among the collected samples, microplastics with polyethylene structure had the highest amount between polyester, polypropylene, and polystyrene groups. This illustrates the use of large amounts of plastic bags and bottles in tourist areas has an essential role in increasing this type of polymer. The small microplastics and their greater ability to be swallowed by aquatic animals also show their extraordinary potential as a substrate for the absorption of other pollutants.
