The primary objective of this study was to investigate the effects of climate change on mercury (Hg) mobilization in areas of the Büyük Menderes River (BMR) basin, where sediment is transitioning to soil or has the potential to do so. Fractionation studies using the European Community Bureau of Reference (BCR) sequential extraction procedure yielded the following ranges: for sediment F1 nd-3.93%, F2 nd-9.81%, and F3 + F4 88.40–99.84%; for soil F1 nd-11.75%, F2 nd-25.86%, and F3 + F4 62.40–99.86%. The combined F1 + F2% fraction, which is easily released into the ecosystem and bioavailable to organisms, was found to be higher in soil areas (5.3%) than in sediment (3.1%). Although the fractional analysis indicates that a greater proportion of Hg is present in the less mobile F3 + F4 phases compared to F1 and F2, the sum of all fractions (∑F) and the total Hg concentration reveal that soil generally attains higher values than sediment. The mean Hg concentration (6.43 μgL −1 ) in water samples was higher than the WHO standard value, and high values were detected in plant samples and physicochemical parameters (except pH) in the soil ( p < 0.05). The mean contamination and ecological risk indices were also higher in the soil than in the sediment. In the human health risk assessment, the Hazard Index (HI) for both sediment and soil was determined to be <1. Based on the integration of different chemical and analytical approaches, it was concluded that Hg is more mobile and has higher bioavailability for living organisms in the soils of the BMR basin. • Soil areas that are transforming to a potential source of Hg are affected by climate change. • BCR sequential extraction procedure F1 + F2 fraction results are higher in soil than in sediment. • The average results of contamination and ecological risk indices are higher in soil than in sediment. • Hg is more mobile and has greater bioavailability for living organisms in soil compared to sediment.
Zeynalova et al. (Mon,) studied this question.