Toxicological health risk analysis of hazardous trace elements accumulation in the edible fish species of the Black Sea in Türkiye using multivariate statistical and spatial assessment

In the current study, the levels of eleven hazardous trace elements (HTEs) were measured in five different fish species frequently consumed in eleven cities along the Black Sea coast of Türkiye. And also the maximum permissible limits (MPLs) specified by international standards are compared to 11 HTEs levels. In addition, human health risk levels from fish consumption were assessed using multiple approaches. The highest metal concentrations of Fe, Mn, Co, Cr, Ni, Cd and Hg were detected in the fish sampled from Samsun city. It was determined that Cu, Zn, Pb and As metal concentrations were the highest in fish sampled from Düzce city. In the demersal Mullus barbatus (MB), the highest quantities of As, Cr, Mn, Fe, Co, Ni, Hg, and Pb were discovered. The highest concentrations of Zn and Cd were found in Engraulis encrasicolus (EE), which is a topminnow fish. The highest concentrations of Cu were found in Sarda sarda (SS), which is a topminnow fish. For all HTEs, the metal hazard index (MPI) and target hazard quotients (THQ) from metal intake by ingesting fish species were less than 1, indicating no risk from consumption. All investigated fish species were acceptable (10^-4 to 10^-6) in terms of carcinogenic risks (CR) from exposure to inorganic arsenic (_iAs). Additionally, because the hazard index (HI) is less than 1, it has been determined that consuming certain fish species will not pose a risk to public health. The predicted daily intakes of HTEs in each fish species were far lower than their corresponding acceptable daily intakes, indicating that consuming fish would not put consumers at risk for health problems from daily intakes of HTEs. In addition, the multivariate statistical analysis justified that HTEs were from anthropogenic and lithogenic origin.

A GIS-based multi-criteria model for offshore wind energy power plants site selection in both sides of the Aegean Sea

Location selection for offshore wind farms is a major challenge for renewable energy policy, marine spatial planning, and environmental conservation. This selection constitutes a multi-criteria decision-making problem, through which parameters like wind velocity, water depth, shorelines, fishing areas, shipping routes, environmental protection areas, transportation, and military zones should be jointly investigated. The aim of the present study was thus to develop an integrated methodology for assessing the siting of bottom-fixed offshore wind farms in two different countries (with different legal, political, and socio/economic characteristics). Our methodology combined multi-criteria decision-making methods and geographical information systems and was implemented in Cyclades (Greece) and in the sea area of İzmir region (Turkey). Experts used fuzzy sets and linguistic terms to achieve more consistent and independent rankings and results. In the Turkish region, the results showed that 519 km² (10.23%) of the study area is suitable for offshore wind farms, while in the Greek region, only 289 km² (3.22%) of the study area was found to be suitable. This spatial suitability analysis may contribute to provide some useful recommendations for the spatial marine planning at the regional scale, as well as for the preliminary assessment of new offshore wind farms in both countries.

Geographic information system-assisted site quality assessment for hazelnut cultivation using multi-criteria decision analysis in the Black Sea region, Turkey

Developing land suitability models for strategically critical agricultural products to expand sustainable agricultural policies and sensitive agriculture management has become a significant trend. This study aims to improve a unique land suitability model for hazelnut cultivation by applying the criteria set (7 main criteria, 35 sub-criteria) including qualitative and quantitative reasons, integrated fuzzy analytic hierarchy process, inverse distance weighting, multi-criteria decision analysis, geographic information system, and weighted linear combination approaches. The model developed in the present study was applied and tested in Ünye District of Ordu Province, where hazelnut production in the Eastern Black Sea region of Turkey is an important economic activity. While 71.17% of the study area is classified as very highly suitable, highly suitable, and moderately suitable, 28.83% of the study area has marginally suitable and unsuitable properties for hazelnut cultivation. Generally, it was determined that the coastal parts of the study area were the most suitable areas for hazelnut growing. The hazelnut land suitability model's two main criteria impacting the final score values are climatic and topographic conditions, respectively. Heavy metal pollution and physical, chemical, and fertility conditions related to soil properties followed these, respectively. The first ten sub-criteria with the highest weight value were determined as elevation, annual average temperature, annual average precipitation, aspect, annual average relative humidity, nickel (pollution), slope, annual average maximum temperature, lead (pollution), and soil depth, respectively. Existing hazelnut cultivation areas were used to test the model. Of the existing cultivation areas, 75.59% coincided with the very highly suitable, highly suitable, and moderately suitable classes presented in this study, while 17.15% were in marginally suitable and 7.26% in unsuitable classes. The study results reveal that the hazelnut land suitability model developed is suitable in mild climate conditions. Using this model as a general transition model will be beneficial to test it in areas containing similar climatic conditions and various soil properties. This study will create a rational background in ensuring the sustainable food production system and security, agricultural land use planning, strategic planning and management of the hazelnut plant, increasing agricultural productivity and income, and the ecosystem.

Spatial distribution of health risk assessment of a drinking water reservoir exposed to urban agglomeration and industrial lead contamination in Istanbul, Türkiye

The Ömerli Dam, supplied by multiple rivers that provide a major amount of Istanbul's water demands for drinking and irrigation, is experiencing toxicological threats due to rapid expansion, increased industrial activity, and population growth in light of the impending global drought. In this study, multivariate statistical analysis and spatial distribution based on geographic information system (GIS) was used to examine the status of pollution and health risk, irrigation water quality, and stochastic geo-environmental risk sources of 16 potentially toxic elements (PTEs: Na, Mg, K, Ca, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Cd, Hg, and Pb) concentrations from samples in the dam. Also, spatial analyzing of quality indices was used to assess the dam's feasibility for irrigation and drinking. As per the results of the study, the dam water has mild heavy metal (loid) pollution, which is measured at 16 PTE by the heavy metal (loid) pollution index (HPI) and heavy metal (loid) evaluation index (HEI) values. The pollution level is low during the rainy season and moderate during the dry season. The water at sampling station S3 (HPI = 146.50) is unfit for consumption and cannot be used for drinking. The majority of harmful metal species exhibited elevated concentrations (notably Pb: 51.78 μg/L, Cr: 8.55 μg/L) in the dam lake water, particularly during the dry season. The toxic metals Pb and Cd account for 15.95% of the total variance, with a high degree of loading. Lead concentrations were found to be above WHO and USEPA limit values only in S2 and S4 during the wet season, but above 0.01 mg/L in all stations except S1 during the dry. Dam water is acceptable for agricultural use, according on the results of the, sodium absorption rate, the percentage of Na and the magnesium damage index, average SAR < 0.9, Na% < 25, and MH < 50, respectively. HQingestion and HI values (all less than 1 in all PTEs) indicate that noncarcinogenic impacts might occur. PRACTITIONER POINTS: Ömerli Dam provides most of the drinking and potable water needs of a mega city like Istanbul. With this study, toxic metal pollution of dam surface water and its possible effects on human health were analyzed for the first time on a spatially wide scale.