Industrial chemicals in irrigated agricultural soils: a case study on the Great Bačka Canal, Vojvodina Province, Serbia

Industrial chemicals, together with other micropollutants, are increasingly found in agricultural soils, mainly due to irrigation with surface waters receiving wastewater discharges, as well as the use of treated wastewater or sludge in crop production. In Serbia’s intensively cultivated Vojvodina Province, irrigation practices often rely on water from the Danube-Tisa-Danube Hydro-System. Within this canal network, the Great Bačka Canal represents one of the most contaminated stretches due to a prolonged history of industrial and municipal effluents. Continuous use of the Great Bačka Canal water for agricultural irrigation creates conditions in which soils may act as long-term repositories for a broad spectrum of different contaminants. Thus, the objective of this study is to characterise the occurrence and distribution patterns of industrial chemicals in soils exposed to irrigation with water from the Great Bačka Canal.

To assess this potential occurrence, 100 soil samples were collected from four agricultural fields regularly irrigated with water from Great Bačka Canal. The samples were processed using the QuEChERS extraction protocol and analysed by liquid chromatography - high-resolution mass spectrometry. A comprehensive suspect-screening workflow was implemented to identify industrial chemicals repeatedly occurring in the soil samples. Contaminants were ranked according to detection frequency and annotation confidence, after which selected candidates were quantified using reference standards. Among detected compounds were triphenyl phosphate, tributyl phosphate, dodecyl sulfate, 2,5-di-tert-butylhydroquinone, triethyleneglycol bis(2-ethylhexanoate), dibutyl phosphate, triethyleneglycol bis(2-ethylhexanoate), and triphenylphosphine oxide with maximum concentrations up to 300 ng/g. The results highlight the importance of robust monitoring schemes that capture realistic exposure scenarios in agricultural areas affected by contaminated water sources, thereby supporting more reliable ecological and human health risk evaluations.

Acknowledgement - This research was supported by the Science Fund of the Republic of Serbia, #GRANT No. 7335, Sustainable environmental monitoring and prediction of pollutants spread – EnviLife.