Investigation of the origin of heavy metals in stream sediment and soils in Abana-Bozkurt (Kastamonu) regions and their risk factors for human health

The study area covers the regions between Ezine Stream (Tezcan, Kozköy, Koşmapınar, Kızılcaelma) and İlişi Stream (Yakaören, Görentaş, Köseali, Deliktaş, Erenler and Alınören) of Abana-Bozkurt (Kastamonu) districts. The study area is located in the northeastern part of Kastamonu city center and covers an area of 2611.411 km² while the study area covers an area of 474.5909 km2 (Ezine basin = 378.6215 km² and İlişi basin = 95.96944 km²). As a result of the field studies, 5 rock (OK), 7 soil (OT), 12 stream sediment (OP) samples were taken from the Ezine stream and 6 rock (IOK), 7 soil (IOT) and 9 stream sediment (IOP) samples were taken from the İlişi stream. 65 element analyses were performed on these samples. Elements that were important for the study were selected for the geochemistry of rock, soil and stream sediments and student-t test was performed and values were calculated. The relationships between trace elements analyzed in rocks, soils and stream sediments collected from the Ezine stream and İlişi stream were evaluated with simple correlation analyses. Considering the analysis results of soil and stream sediments collected from the study area, the indexes used for pollution studies in the literature (geoaccumulation index (Igeo), enrichment factor (EF), pollution factor (CF), pollution load index (PLI), potential ecological risk index (Eri), potential toxicity index (RI), Nemerow pollution index (NIPI) were taken as basis and calculations were made. In addition, in the examination of carcinogenic risk factors, the results of 3 factors, namely inhalation, ingestion and dermal effects, were investigated for adults and children. In order to determine the risk levels for human health based on the analysis results of soil and stream sediment samples collected from the Ezine and İlişi streams, "average daily dose" calculations of heavy metals for adults and children were carried out, including ingestion, inhalation and dermal contact, and classifications were made as "negligible", "low", "moderate" and "high" according to the results obtained. Within the scope of the evaluation of the distribution and anomaly of elements in rocks, soils and stream sediments, anomaly maps were prepared according to the content of heavy metals (in ppm) in the samples in accordance with their distribution environments in the field and were interpreted by comparing them with standard values in various environments (earth crust, mafic and acidic rocks, ultramafic rocks, calcareous rocks, sandstones and soil). Within the scope of the thesis study, non-carcinogenic health risks (HI) and total carcinogenic risks (TCR) of heavy metals were calculated for adults and children using Monte Carlo simulation based on Crystal System Ball software, which can analyze the probabilistic distribution of health risks. Graphs were drawn using the values found and risk values were interpreted on the basis of average values, considering the distributions. In soil samples collected from Ezine and İlişi streams, EF values calculated for heavy metals were taken and Q-Q plot graphics were drawn in OriginPro program and the origin of these metals was examined as geogenic, anthropogenic or both. In the evaluation made for Ezine stream soil samples, it was determined that Cd heavy metal showed a symmetrical distribution. This indicates that the origin of the source metal is geogenic. The distributions of Al, As, Cr, Cu, Hg, Mn, Ni, Pb and Zn heavy metals are asymmetric. According to these results, the concentration ranges of these heavy metals in Ezine stream soil indicate the existence of multiple populations originating from geogenic and anthropogenic enrichment. In the evaluation made for İlişi stream soil samples, it was determined that Cd and Hg heavy metals showed a symmetrical distribution. This indicates that the origin of the source metal is geogenic. The distributions of Al, As, Cr, Cu, Mn, Ni, Pb and Zn heavy metals are asymmetric. According to these results, the concentration ranges of these heavy metals in the İlişi stream soil indicate the existence of multiple populations resulting from geogenic and anthropogenic enrichment. In the studies conducted within the scope of the Evaluation of Heavy Metal Amounts in Soil Samples Collected from Ezine and İlişi Stream According to Regulations; Based on the World Health Organization/Food and Agriculture Organization data; it was determined that As in the Ezine Stream region; "Contaminated area that needs to be cleaned in accordance with the process determined by the Ministry"; and for Ni, Fe and Mn; "A site that requires follow-up subject to the second stage assessment process". It was determined that Mn in the İlişi Stream region; "A site that requires follow-up subject to the second stage assessment process". Within the scope of the thesis study, it is recommended to use methods such as electrokinetic extraction, in situ chemical immobilization, vitrification, which have been used worldwide in recent years, in order to eliminate pollution in soil and stream sediments and to minimize their negative effects on living health (non-carcinogenic and carcinogenic risk factors).