A Multidisciplinary Assessment of Pharmaceuticals in Wastewaters: A Comparative Study of Oman and South Australia

<p dir="ltr">The escalation of human activities, particularly the proliferation of pharmaceutical traces in waterways, poses a substantial threat to the environment and human well-being. This issue has become a global concern due to the widespread impact of pollution resulting from heightened pharmaceutical production and usage. Despite the gravity of the situation, environmental laws, regulations, and policies on pharmaceutical control are yet to attain a comprehensive global maturity. The incongruity between the surge in pharmaceutical production and the nascent state of regulatory frameworks is a cause for significant concern. The current state of global environmental legislation, regulatory mechanisms, and policy frameworks emphasizes their inadequacy in addressing the burgeoning challenges posed by pharmaceutical contamination.</p><p dir="ltr">In this research project, an examination was conducted on pharmaceutical contamination of influent, and effluent wastewater samples from two countries that employ different wastewater treatment methodologies. Additionally, sludge samples from Oman were included to assess radiopharmaceutical contamination. These samples, known for their wide reusage and rich history in pollution research, were analysed to survey the extent of pharmaceutical contamination. Then, field studies focused on regions in Oman and South Australia, and reporter genes bioassays were employed to quantify responses precisely elicited by biologically active chemicals present in the samples. Furthermore, antibiotics' impacts on environmental aquatic organisms, particularly the non-targeted duckweed species, Lemna minor (L. minor), were examined.</p><p dir="ltr">In Chapter 3, influent, effluent, and sludge samples were obtained from eight wastewater treatment plants (WWTPs) in Oman, quantifying nineteen pharmaceuticals and four radiopharmaceuticals in influent, effluent, and sludge samples. Sixty-nine percent of pharmaceuticals were partially or fully removed, while thirty-one percent showed higher effluent concentrations, suggesting accumulation after treatment. Most compounds detected as prominent pharmaceutical constituents were identical in diverse wastewater samples, with variations in concentrations.  </p><p dir="ltr">In Chapter 4, wastewater samples from 10 WWTPs in Oman and 2 WWTPs in South Australia were exposed on a panel of mammalian cell lines using CALUX® (Chemically Activated LUciferase eXpression) assays and epithelial fish cell line. Significant ROS levels and glucocorticoid receptor (GR) activity accumulated in cell lines exposed to wastewater from certain WWTPs in Oman, while notable ERα activity (0.045-0.073 ng/L E2 equivalent) was found at specific sites in Oman and South Australia. In Chapter 5, three antibiotics that are commonly found in the environment and in wastewater effluents—Ciprofloxacin (CIP), Erythromycin (ERY), and Sulfamethoxazole (SMX)— were studied to investigate their impact on the growth and physiological variables of the higher-order aquatic plant L. minor over 3 subsequent generations. Significant antibiotic effects on frond number, frond and root areas were found across generations and treatment days. The study underscores the urgent need for more robust and coordinated efforts to improve wastewater treatment and to safeguard the environment and human civilization from the adverse consequences of pharmaceutical contamination in the present and future scenarios.</p>