Basin scale monitoring of microplastics and phthalates in sediments from the Persian Gulf and the Gulf of Makran using GIS-based algorithms: Insights towards spatial variation and potential risk assessment

• Published in: The Science of the total environment Vol. 927; p. 171950
• Main Authors: Aghadadashi, Vahid, Mehdinia, Ali, Rezaei, Mahdie, Molaei, Saeideh, Seyed Hashtroudi, Mehri, Ahmadian, Fatemeh, Hamzehpour, Ali, Rahnama, Reza
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.06.2024
• Subjects: basins; confidence interval; environment; fuzzy logic; Microfibers; microplastics; Persian Gulf; phthalates; Phthalates esters; risk assessment; Spatial outliers; Trend analysis; Voronoi polygons; Persian Gulf; Voronoi polygons; Microfibers; Phthalates esters; Spatial outliers; Trend analysis
• ISSN: 0048-9697; 1879-1026; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.171950

Information on sedimentary microplastics and phthalates has been restricted to the coastal regions of the Persian Gulf and the Gulf of Makran. Our basin-wide study monitored their levels, spatial behaviors, and potential risks using GIS-based techniques. Microplastics and phthalates ranged from 5 to 75 particles/kg d.w and 0.004–1.219 μg g−1 d.w, respectively. Microplastics were in the size category of 100 μm to 3 mm, and black microfibers (< 1 mm) and high-density polymers were dominant. The total number of microplastics was between 356.333 × 1012 and 469.075 × 1012 particles in the surface sediments of the studied regions (confidence interval = 99 %). Diethylhexyl phthalate (DEHP) and Di-isobutyl phthalate contributed 88 % of detected phthalates. Significant correlations among microplastic abundance, total phthalates, and DEHP were distinguished (p < 0.05). Overall, the findings reiterated the widespread presence of microplastics and a potential link between phthalates and microplastics. Semi-variogram, cluster Voronoi polygons, and Trend analysis identified spatial outliers and major deposition sites of microplastics and phthalates and consequently outlined the localities where upcoming studies should be concentrated. A hotspot of potential risks was marked using Fuzzy logic and GIS-based algorithms in the Sea of Makran, covering an area equal to 342. 99 km2. [Display omitted] •Black fibers (0.5–1 mm) and high-density microplastics (MPs) were dominant.•The total number of MPs was between 3.56 × 1014 and 4.69 × 1014 in the studied regions.•A significant correlation existed between Diethylhexyl phthalate (DEHP) and MPs.•Di-isobutyl phthalate and DEHP contributed 88 % of the detected phthalates.•Phthalate and MP load were independent of sediment properties except for MPs <1 mm.