Prevalence of pharmaceutical compounds and heavy metals in municipal wastewater and river waters of Gazipur District of Bangladesh: ecological risk assessment

The occurrence of heavy metals and pharmaceuticals in aquatic ecosystems poses significant threats to human health and ecological integrity, profoundly affecting fisheries productivity and the availability of drinking water. This study intended to evaluate the current status of heavy metals and pharmaceuticals (metronidazole and ibuprofen) in the hospital wastewater, river water, effluents of pharmaceutical industries, and municipal wastewater of Gazipur district, elucidating their potential health and ecological hazards. Heavy metals (Cr, Ni, Cd, Pb, Cu) were detected via Inductively Coupled Plasma Mass Spectrometry (ICP-MS), while pharmaceutical compounds (metronidazole and ibuprofen) were analyzed using the HPLC-UV. The mean concentrations of Cd (7.4–35.3 μg/L), Ni (<LOD – 275.2 μg/L), Pb (257.2–517.2 μg/L), Cr (<LOD – 226.3 μg/L), and Cu (6.52–100 μg/L) were varied among different water sources. The most abundant metals were Pb and Cu in the effluent of the pharmaceutical industry, while high concentrations of Ni were observed in river water and Cd and Cr in municipal wastewater. Remarkably, Cr was not detected in river water. The CF values indicated comparatively high Pb, and Cd contamination levels, whereas Ni, Cr, and Cu showed a lower risk. The PLI underscored substantial pollution levels in the study area. Hospital water exhibited no presence of metronidazole, while ibuprofen was absent from all types of samples. Metronidazole was detected in municipal wastewater (0.80 ± 0.042 μg/mL) and river water samples (0.56 ± 0.047 μg/mL), surpassing permissible limits and HQ, indicating potential harmful effects on public well-being and the environment. This study emphasizes the pressing need for local authorities and regulatory agencies to establish stringent guidelines to mitigate water pollution effectively and safeguard environmental and public health.