Effects of Irrigation with Untreated Wastewater on Plasticizer Accumulation and Uptake in Olive Trees

In many developing countries, the reuse of wastewater for irrigation is increasingly practiced as a strategy to address water scarcity. However, this approach raises concerns about the environmental dispersion of contaminants, particularly persistent, bioaccumulative, and potentially endocrine-disrupting chemicals. This study investigated the occurrence of phthalic acid esters (PAEs), non-phthalate plasticizers (NPPs), and bisphenol A (BPA) in untreated industrial poultry wastewater (PWW), their accumulation in soil, and their uptake by young olive trees (Olea europaea L., cv. Chemlali) irrigated through drip systems. Three experimental plots were established: one irrigated with tap water (TW), another with undiluted PWW, and a third with PWW diluted with tap water (50:50) (v/v). Water, soil, olive leaf, and root samples were analyzed using a GC/MS based workflow validated for seven target analytes, including PAEs, NPPs and BPA. Bibliographic data demonstrated that poultry breeding wastewater is a potential reservoir of microplastics. Surprisingly, none of the target contaminants were detected in the wastewater, yet all soil samples contained measurable levels of the investigated pollutants (0.468 to 5.736 µg/kg), most likely originating from previous agricultural practices. Bis(2-thylhexyl) Phthalate (DEHP) and diisononyl phthalate (DiBP) were the most prevalent compounds. In plant tissues, plasticizer concentrations were low (0.046 to 2.465 µg/kg), suggesting limited uptake by olive trees, while BPA was absent from both leaves and roots. Although the concentrations remained below international safety thresholds, the detection of contaminants highlights the need for continuous monitoring. Further research is necessary to investigate other emerging contaminants and evaluate their combined impact on agroecosystems.