Phthalate Esters in Agricultural Soils of Udu, Delta State, Nigeria; Spatial Distribution and Potential Risks Assessment

Abstract

Phthalate esters (PAEs) are widely used plasticizers that can leach into agricultural soils through plastic mulching films, irrigation pipes, and agrochemical residues, posing potential ecological and human health risks. This study assessed the spatial distribution and potential risks assessment of six PAEs in agricultural soils from Udu, Delta State, Nigeria. Soil samples were collected from twenty locations and analyzed using gas chromatography–mass spectrometry detector (GC–MSD) after extraction by ultrasonication. Total PAE concentrations (Σ6 PAEs) ranged from 8.46 to 40.3 ng g^-1. On average, Diethyl Phthalate (DEP), Di(2-ethylhexyl) phthalate (DEHP) and Butyl benzyl phthalate (BBP) were the dominant congeners. Analysis of variance (ANOVA) indicated no significant variations (p > 0.05) in PAEs concentrations in among the locations. The potential risks assessed using hazard index and total cancer risk indicated that the risks for both children and adults were generally within acceptable limits. Although the overall risk levels were low, the persistence and bioaccumulative nature of DEHP and related congeners indicate potential long-term impacts on soil quality and food safety. The findings highlight the need for continuous monitoring, regulation of agricultural plastic usage, and adoption of biodegradable alternatives to mitigate phthalate contamination in farmlands and safeguard public health.