Evaluation of ecological and health risks of trace elements in soils of olive orchards and apportionment of their sources using the APCS-MLR receptor model.

Izmir, Turkey's third most populous city, is in an important position in terms of both agriculture and industry. The province, which contributes 9.3% to the country's industrial production, also has an important potential in terms of olive cultivation. However, until now, no research has been undertaken to analyze the content of trace elements (TEs) in the soil of olive orchards in Izmir. This study was carried out to determine the pollution level and ecological risks of TEs in the olive orchards soils of Izmir province, to reveal their potential sources and to evaluate their health risks. Among the TEs, the average content of only Ni (37.9 mg/kg) exceeded the world soil average content (29 mg/kg), while the average content of only Cd (0.176 mg/kg) exceeded the upper continental crust content (0.09 mg/kg). Enrichment factor revealed that there was significant enrichment for Cd in 73.6%, Ni in 11.6% and Cr in 5.4% of olive orchards, respectively, due to polluted irrigation water and agrochemicals. Similarly, ecological risk factor indicated that there were moderate and considerable ecological risks for Cd in 48.8% and 23.3% of olive orchards, respectively. Absolute principal component scores-multiple linear regression (APCS-MLR) model showed that Ni and Cr in the study area are affected by agricultural sources, Al, Co, Cu, Fe, Mn, Pb and Zn originate from lithogenic sources, and Cd originates from mixed sources. Based on health risk evaluation methods, non-carcinogenic and carcinogenic effects would not be expected for residents. This study provides significant knowledge for evaluating soil TE pollution in olive orchards and serves a model for source apportionment and human health risk evaluation of TEs in other agricultural regions.

Boron contamination and related health risk assessment in the soils collected from olive groves in Izmir province, Türkiye.

Although boron (B) is an essential element for plants, high levels are also toxic. In this respect, pollution of soils by B may pose a serious problem for ecosystem and human health. On the other hand, studies evaluating the ecological and human health risks that may arise due to B contamination in agricultural soils are limited. In this study, it was aimed to determine the B pollution degree of the soils taken from the olive groves of Izmir province, which is approximately 180 km away from the B deposits in the Bigadiç district. In addition, the factors affecting boron adsorption and availability were discussed and the ecological and health risks of boron were evaluated. For this, soil samples were collected at depths of 0-30 cm from 118 olive groves and their B, Al, Fe, pH and organic matter contents were determined. The mean B content (47.08 mg/kg) of the study area was comparable to world-soil average B concentration (42 mg/kg). Also, B had a "low potential ecological risk" in the study area according to the ecological risk index results. On the other hand, based on the results of contamination factor (Cf) and enrichment factor (EF), "moderate contamination" and "significant enrichment" were found in the study area for B. These findings indicated that the B content in the study area is mainly related to the soil parent material, but irrigation water also contributes slightly to B content. Correlation analysis results suggested that Al and Fe contents of the soils in the study area may have an effect on B adsorption. The results of health risk assessment indicated non-carcinogenic effects are not expected for adults and children exposed to soil B content by ingestion, dermal contact and inhalation.