Ecological risk assessment, source identification and spatial distribution of organic contaminants in terms of mucilage threat in streams of Çanakkale Strait Basin (Türkiye).

In this study, the spatial distributions of organic contamination stressors in water of fluvial habitats in the Çanakkale Strait (ÇS) watershed were investigated and the data were assessed in terms of human health and mucilage threat. Seven significant riverine ecosystems flowing into the ÇS were defined in the basin. Water samples were taken in the spring season (2023), when the phytoplankton communities reach their highest densities. Then they were tested for a total of 8 limnological parameters. The Nutrient Pollution Index (NPI) and Water Quality Index (WQI) were applied to assess the comprehensive quality characteristics of waters. The Hazard Quotient (HQ) and Hazard Index (HI) were applied to indicate the prospective non-carcinogenic human health risks of organic stressors. Principal Component Analysis (PCA) and Cluster Analysis (CA) were applied to categorize the investigated habitats and define the sources of investigated contamination parameters. Also, Geographic Information System (GIS) was used to make an effective assessment through visualization. The determined spatial mean values of the measured variables in ÇS watershed as follows: 18.21 °C for temperature, 8.51 mg/L for DO, 4.57 NTU for turbidity, 3.95 mg/L for suspended solids, 1.11 mg/L for NO3-N, 0.012 mg/L for NO2-N; 0.173 mg/L for PO4-P and 2.32 mg/L for BOD. It has been determined that the organic pollution loads and water temperature values of the investigated sub-basins increase from the upstream to the downstream locations and Çanakkale Stream was recorded as the riskiest fluvial habitat for the ÇS watershed. According to the results of health risk assessment indices, non-carcinogenic risks of organic pollutants would not be expected for all age groups.

Ecotoxicological evaluation of organic contamination in the world's two significant gateways to the Black Sea using GIS techniques: Turkish Straits.

This study was carried out to determine the spatial-temporal distributions of limnological parameters of Çanakkale Strait (ÇS) and Istanbul Strait (IS), Turkiye. Fluvial (n = 11) and lacustrine (n = 4) habitats water samples were collected in the dry and rainy seasons of 2022-2023. Among limnological parameters, the highest mean electrical conductivity values of 6063 µS/cm were noted in the IS basin during the rainy season and the lowest was 0.04 mg/L for nitrite in the ÇS basin. Generally, the levels of organic contaminants and ecological risk indices were as follows: rivers of IS > rivers of ÇS > Alibey Dam Lake (IS) > Atikhisar Dam Lake (ÇS). The highest non-carcinogenic health risks of 0.88 were noted for children in the ÇS basin during the dry season and the lowest of <0.01 in Atikhisar Dam Lake during the rainy season. Multivariate statistical techniques were applied to data to categorize investigated ecosystems and sources apportionment of contaminants and geospatial distribution.

Assessment of the effects of COVID-19 lockdown period on groundwater quality of a significant rice land in an urban area of Türkiye.

In the current research, the impact of the COVID-19 lockdown period on groundwater quality of Lower Meriç Plain (Thrace Region of Türkiye) was evaluated. Some significant nutrient characteristics (NO3-, NO2-, and PO43-), salinity characteristics (EC, TDS, and salinity), and physical characteristics (temperature, DO, pH, and turbidity) were investigated in groundwater samples collected from 45 sampling points in pre-lockdown and lockdown periods. Water quality index (WQI) and nutrient pollution index (NPI), Pearson correlation index (PCI), cluster analysis (CA), one-way ANOVA test (OWAT), and factor analysis (FA) were applied to assess ecological risk. Excluding recorded statistical differences in temperature and DO due to climatic conditions (p < 0.05), levels of all the investigated water quality parameters show no statistically significant differences and no significant reduction in pollutants measured in the lockdown period. On the contrary, the WQI and NPI scores have increased between the rates of 4.76-27.10% during the lockdown period. In the lockdown period, although the reduction of industry or limited production of many industrial facilities reduced the inorganic contaminant releases to the environment, ongoing agricultural activities and domestic wastes caused to prevent the reduction of organic pollutants in groundwater of the region during the lockdown period.