Urbanization-driven soil degradation; ecological risks and human health implications

Urban soils contaminated with heavy metals and pesticide residues are of great concern because of their adverse impact on human health. A total of 66 agricultural topsoil samples (15 cm) were collected to represent the study area and determine how anthropogenic activities adversely affect soil quality and human health. Sampling was conducted in the summer, when it was dry and hot, and in the winter, after atmospheric deposition. Seventeen potentially hazardous metals/metalloids (Ag, As, Al, B, Ba, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Mo, Pb, Se, Zn, and V) were measured in the soils. The mean concentrations of metals ranged between 0.05 and 8080 mg/kg, and their distribution was site-specific, with high pollution at the sampling sites owing to proximity to human activities. In agricultural areas, the greatest arsenic concentration was recorded at 48 mg/kg. The potential ecological risk index (PERI) and health hazard index (HI) were calculated, as well as metal contamination indices including contamination factor (Cf), geo-accumulation index (Igeo), and pollution load index (PLI). The mean PLI was calculated to be 4.89, indicating that the area is highly polluted. The potential ecological risk index showed remarkably high risks for As, Cd, and Hg, and moderate risks for Ni and Pb. The arsenic hazard index (HI) was greater than one (2.41) in children, indicating a risk of exposure through ingestion. Pesticide residue analyses were performed in areas where the metal intensity was high. Banned or restricted organochlorine pesticide (OCPs) residues, including, dieldrin, endrin ketone, endosulfan I, II, heptachlor, heptachlor epoxide, lindane (γ-HCH), PP-DDD, and methoxychlor, were detected between 0.002 and 1.45 mg/kg in the soil samples.

Method validation for the analysis of pesticide residue in aqueous environment

Rapid industrialization and urbanization have led to severe pollution into water resources which limits to reach safe drinking and irrigation water globally. One of the most important pollutants of environment that brought along with industrialization and technology are pesticides. In this study, it was aimed to investigate the pesticide residues in Dim Stream, due to intense touristic and agricultural activities in the region. Thus, four locations alongside the river were selected for sampling to evaluate the pesticide residue in the stream. The water samples were collected representing the rainy and dry seasons and extracted according to the Quechers method which is validated in terms of accuracy, specificity, limit of detection (LOD), and quantification (LOQ). Pesticide residues were analyzed by injecting LC-MSMS and GC-MS. The most recurrent pesticides were cypermethrin, endosulfan, deltamethrin, dicofol, metribuzin, parathion-methyl, permethrin, malathion, and tetradifon in the samples. Some of the levels of pesticides detected in water were significantly high compared with guideline values set by the Surface Water Quality Regulation of Turkey, EU, and World Health Organization, and this may be hazardous to aquatic life and human health. The obtained 18 recoveries of pesticides in the samples varied between 70 and 120%. LOD was ranged 19 from 0.23 to 9.67 μg/L. LOQ of 11 of the pesticides were higher than 1 μg/L.