Oman is a high-income country with a pharmaceutical market estimated at USD 421 million, and most pharmaceuticals are provided to people for free. These pharmaceuticals can be released into aquatic environments. There are direct pathways, such as treated wastewater (WW) and manure usage in cultivation, and indirect pathways, due to human and animal intake.
Currently, there is a lack of studies reporting environmental sources and levels of pharmaceuticals in Oman. The main objective of this study was to assess the extent and magnitude of pharmaceuticals and specifically antibiotics in the environment that allow estimation of their potential hazards as mixtures in the receiving environment in Oman.
Samples were collected from influent and effluent WW and sludge samples from WWTPs in Oman according to standard sampling procedures. The quantification of the pharmaceuticals residues was carried out using liquid chromatography-mass spectrometry techniques. For the detection of radiopharmaceuticals, samples were processed using Low Gamma-Ray Spectrometry.
Various pharmaceuticals were detected in different sample matrices, including paracetamol, atenolol, erythromycin, gliclazide, metformin, and metronidazole. For the radiopharmaceuticals, Ga-67 was the highest detected radiopharmaceutical in WW samples, while in sludge samples, the highest detected radiopharmaceutical was I-131.
This study confirms the presence of pharmaceuticals and radiopharmaceuticals in WWTPs' influent, effluent, and sludge in Oman. These pharmaceuticals are accumulating over time, and they could be of concern as their presence in receiving environment have potential ecotoxicological risks.
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